The lamellated connective tissue constituting the thickest layer of the cornea between the Bowman and Descemet membranes.
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Inflammation of the cornea.
Fibroblasts which occur in the CORNEAL STROMA.
A sulfated mucopolysaccharide initially isolated from bovine cornea. At least two types are known. Type I, found mostly in the cornea, contains D-galactose and D-glucosamine-6-O-sulfate as the repeating unit; type II, found in skeletal tissues, contains D-galactose and D-galactosamine-6-O-sulfate as the repeating unit.
Stratified squamous epithelium that covers the outer surface of the CORNEA. It is smooth and contains many free nerve endings.
Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.
Diseases of the cornea.
Partial or total replacement of the CORNEA from one human or animal to another.
A noninflammatory, usually bilateral protrusion of the cornea, the apex being displaced downward and nasally. It occurs most commonly in females at about puberty. The cause is unknown but hereditary factors may play a role. The -conus refers to the cone shape of the corneal protrusion. (From Dorland, 27th ed)
Filarial infection of the eyes transmitted from person to person by bites of Onchocerca volvulus-infected black flies. The microfilariae of Onchocerca are thus deposited beneath the skin. They migrate through various tissues including the eye. Those persons infected have impaired vision and up to 20% are blind. The incidence of eye lesions has been reported to be as high as 30% in Central America and parts of Africa.
A layer of the cornea. It is the basal lamina of the CORNEAL ENDOTHELIUM (from which it is secreted) separating it from the CORNEAL STROMA. It is a homogeneous structure composed of fine collagenous filaments, and slowly increases in thickness with age.
Bilateral hereditary disorders of the cornea, usually autosomal dominant, which may be present at birth but more frequently develop during adolescence and progress slowly throughout life. Central macular dystrophy is transmitted as an autosomal recessive defect.
The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.
An excessive amount of fluid in the cornea due to damage of the epithelium or endothelium causing decreased visual acuity.
A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).
New blood vessels originating from the corneal veins and extending from the limbus into the adjacent CORNEAL STROMA. Neovascularization in the superficial and/or deep corneal stroma is a sequel to numerous inflammatory diseases of the ocular anterior segment, such as TRACHOMA, viral interstitial KERATITIS, microbial KERATOCONJUNCTIVITIS, and the immune response elicited by CORNEAL TRANSPLANTATION.
Single layer of large flattened cells covering the surface of the cornea.
A dye obtained from the heartwood of logwood (Haematoxylon campechianum Linn., Leguminosae) used as a stain in microscopy and in the manufacture of ink.
Gas lasers with excited dimers (i.e., excimers) as the active medium. The most commonly used are rare gas monohalides (e.g., argon fluoride, xenon chloride). Their principal emission wavelengths are in the ultraviolet range and depend on the monohalide used (e.g., 193 nm for ArF, 308 nm for Xe Cl). These lasers are operated in pulsed and Q-switched modes and used in photoablative decomposition involving actual removal of tissue. (UMDNS, 2005)
Connective tissue cells of an organ found in the loose connective tissue. These are most often associated with the uterine mucosa and the ovary as well as the hematopoietic system and elsewhere.
A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
Partial or total replacement of all layers of a central portion of the cornea.
A surgical procedure to correct MYOPIA by CORNEAL STROMA subtraction. It involves the use of a microkeratome to make a lamellar dissection of the CORNEA creating a flap with intact CORNEAL EPITHELIUM. After the flap is lifted, the underlying midstroma is reshaped with an EXCIMER LASER and the flap is returned to its original position.
A type of refractive surgery of the CORNEA to correct MYOPIA and ASTIGMATISM. An EXCIMER LASER is used directly on the surface of the EYE to remove some of the CORNEAL EPITHELIUM thus reshaping the anterior curvature of the cornea.
A family of structurally related collagens that form the characteristic collagen fibril bundles seen in CONNECTIVE TISSUE.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Loss of epithelial tissue from the surface of the cornea due to progressive erosion and necrosis of the tissue; usually caused by bacterial, fungal, or viral infection.
Glycoproteins which have a very high polysaccharide content.
Surgical procedures employed to correct REFRACTIVE ERRORS such as MYOPIA; HYPEROPIA; or ASTIGMATISM. These may involve altering the curvature of the CORNEA; removal or replacement of the CRYSTALLINE LENS; or modification of the SCLERA to change the axial length of the eye.
A versatile red dye used in cosmetics, pharmaceuticals, textiles, etc., and as tissue stain, vital stain, and counterstain with HEMATOXYLIN. It is also used in special culture media.
Restoration of integrity to traumatized tissue.
A species of parasitic nematodes widely distributed throughout central Africa and also found in northern South America, southern Mexico, and Guatemala. Its intermediate host and vector is the blackfly or buffalo gnat.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Damage or trauma inflicted to the eye by external means. The concept includes both surface injuries and intraocular injuries.
Proteoglycans consisting of proteins linked to one or more CHONDROITIN SULFATE-containing oligosaccharide chains.
A superficial, epithelial Herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (KERATITIS, DENDRITIC). (Dictionary of Visual Science, 3d ed)
Nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as FLAVIN MONONUCLEOTIDE and FLAVIN-ADENINE DINUCLEOTIDE.
A naturally occurring glycosaminoglycan found mostly in the skin and in connective tissue. It differs from CHONDROITIN SULFATE A (see CHONDROITIN SULFATES) by containing IDURONIC ACID in place of glucuronic acid, its epimer, at carbon atom 5. (from Merck, 12th ed)
Measurement of the index of refraction (the ratio of the velocity of light or other radiation in the first of two media to its velocity in the second as it passes from one into the other).
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
The diffusion or accumulation of neutrophils in tissues or cells in response to a wide variety of substances released at the sites of inflammatory reactions.
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball.
An annular transitional zone, approximately 1 mm wide, between the cornea and the bulbar conjunctiva and sclera. It is highly vascular and is involved in the metabolism of the cornea. It is ophthalmologically significant in that it appears on the outer surface of the eyeball as a slight furrow, marking the line between the clear cornea and the sclera. (Dictionary of Visual Science, 3d ed)
Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.
A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
Heteropolysaccharides which contain an N-acetylated hexosamine in a characteristic repeating disaccharide unit. The repeating structure of each disaccharide involves alternate 1,4- and 1,3-linkages consisting of either N-acetylglucosamine or N-acetylgalactosamine.
A CXC chemokine with specificity for CXCR2 RECEPTORS. It has growth factor activities and is implicated as a oncogenic factor in several tumor types.
One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.
The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Infections in the inner or external eye caused by microorganisms belonging to several families of bacteria. Some of the more common genera found are Haemophilus, Neisseria, Staphylococcus, Streptococcus, and Chlamydia.
A TGF-beta subtype that was originally identified as a GLIOBLASTOMA-derived factor which inhibits the antigen-dependent growth of both helper and CYTOTOXIC T LYMPHOCYTES. It is synthesized as a precursor molecule that is cleaved to form mature TGF-beta2 and TGF-beta2 latency-associated peptide. The association of the cleavage products results in the formation a latent protein which must be activated to bind its receptor.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
A ring of tissue extending from the scleral spur to the ora serrata of the RETINA. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., COLLAGEN; ELASTIN; FIBRONECTINS; and LAMININ).
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Fluids composed mainly of water found within the body.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
Spherical, heterogeneous aggregates of proliferating, quiescent, and necrotic cells in culture that retain three-dimensional architecture and tissue-specific functions. The ability to form spheroids is a characteristic trait of CULTURED TUMOR CELLS derived from solid TUMORS. Cells from normal tissues can also form spheroids. They represent an in-vitro model for studies of the biology of both normal and malignant cells. (From Bjerkvig, Spheroid Culture in Cancer Research, 1992, p4)
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)
A factor synthesized in a wide variety of tissues. It acts synergistically with TGF-alpha in inducing phenotypic transformation and can also act as a negative autocrine growth factor. TGF-beta has a potential role in embryonal development, cellular differentiation, hormone secretion, and immune function. TGF-beta is found mostly as homodimer forms of separate gene products TGF-beta1, TGF-beta2 or TGF-beta3. Heterodimers composed of TGF-beta1 and 2 (TGF-beta1.2) or of TGF-beta2 and 3 (TGF-beta2.3) have been isolated. The TGF-beta proteins are synthesized as precursor proteins.
Group of chemokines with paired cysteines separated by a different amino acid. CXC chemokines are chemoattractants for neutrophils but not monocytes.
A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.
A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
A layer of epithelium that lines the heart, blood vessels (ENDOTHELIUM, VASCULAR), lymph vessels (ENDOTHELIUM, LYMPHATIC), and the serous cavities of the body.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.

Regulation of gelatinase B production in corneal cells is independent of autocrine IL-1alpha. (1/726)

PURPOSE: The matrix metalloproteinase gelatinase B is synthesized by cells at the leading edge of the corneal epithelium migrating to heal a wound. Recent data from the authors' laboratory suggest that excessive synthesis contributes to repair defects. The goal of the study reported here was to investigate mechanisms controlling gelatinase B production by corneal epithelial cells. METHODS: Freshly isolated cultures of corneal epithelial cells and early passage stromal fibroblasts from rabbit were used for these studies. RESULTS: In a previous study, it was found that the cytokine interleukin (IL)-1alpha is released into the culture medium of corneal epithelial cells more efficiently when they are plated at low density with limited cell-cell contact than when plated at high density. In this study, we show that production of gelatinase B by these cells is similarly affected by cell plating density. However, it is further demonstrated that these two events are not dependent on one another but occur in parallel: IL-1alpha does not regulate gelatinase B production (synthesis), nor was there evidence that any other secreted autocrine cytokine acts as mediator. Instead, our data suggest that gelatinase B production is downregulated directly by high cell density and indicate a connection to the level of protein kinase C activity. Nevertheless, the anticancer agent suramin, which blocks collagenase synthesis by interfering with autocrine cytokine-receptor interactions, still inhibits synthesis of gelatinase B. CONCLUSIONS: Unlike collagenase synthesis by corneal stromal fibroblasts, production (synthesis) of gelatinase B does not appear to be controlled by secreted autocrine cytokines but can still be inhibited by suramin. Suramin may make an effective therapeutic agent for controlling pathologic overproduction of gelatinase B in corneal ulcers.  (+info)

Human corneal ablation threshold using the 193-nm ArF excimer laser. (2/726)

PURPOSE: To determine the human corneal threshold ablation energy density for the 193-nm ArF excimer laser, approximating clinical conditions. METHODS: The VISX Star (Santa Clara, CA) 193-nm argon fluoride excimer laser was used to ablate the cornea in human eye bank eyes under clinical conditions. Corneas were exposed to energy densities of 10, 20, 30, 35, 40, 45, and 140 to 160 mJ/cm2. Corneas were fixed for light and transmission electron microscopy immediately after laser exposure. RESULTS: Different ablation thresholds for various corneal structural elements were observed. The ablation threshold for the collagen in the corneal stroma was determined to be 30 mJ/cm2. Keratocytes had ablation thresholds of 40 mJ/cm2. These different ablation thresholds accounted for the production of stromal peaks and valleys, with the keratocytes atop the peaks. CONCLUSIONS: Different corneal structural elements have different ablation threshold energy densities.  (+info)

Differential inhibition of collagenase and interleukin-1alpha gene expression in cultured corneal fibroblasts by TGF-beta, dexamethasone, and retinoic acid. (3/726)

PURPOSE: Expression of the genes for collagenase and interleukin-1alpha (IL-1alpha) are induced as stromal cells become activated to the repair fibroblast phenotype after injury to the cornea. This investigation examines the mechanisms whereby expression of these genes is inhibited by transforming growth factor-beta (TGF-beta), dexamethasone (DEX), or retinoic acid (RET A). METHODS: A model of freshly isolated cultures of corneal stromal cells and early passage cultures of corneal fibroblasts was used in these studies. This model reproduces the events of stromal cell activation in the corneal wound. RESULTS: In early passage cultures of corneal fibroblasts, expression of collagenase is under obligatory control by autocrine IL-1alpha. IL-1alpha controls its own expression through an autocrine feedback loop that is dependent on transcription factor NF-kappaB. TGF-beta, DEX, and RET A were each effective inhibitors of collagenase gene expression in these cells. Furthermore, these agents have the capacity to inhibit expression of IL-1alpha and this was correlated with their ability to affect DNA-binding activity of NF-kappaB. However, TGF-beta, DEX, and RET A were also effective inhibitors of the low level of collagenase expressed by freshly isolated corneal stromal cells that cannot express IL-1alpha. CONCLUSIONS: In cells with an active IL-1alpha autocrine loop there are at least two distinct signaling pathways by which collagenase gene expression can be modulated. The results of this study demonstrate that TGF-beta, DEX, and RET A differentially inhibit collagenase and IL-1alpha gene expression. This information will be useful in the design of therapeutic modalities for fibrotic disease in the cornea and other parts of the eye.  (+info)

A new surgical technique for deep stromal, anterior lamellar keratoplasty. (4/726)

AIMS: To describe a new surgical technique for deep stromal anterior lamellar keratoplasty. METHODS: In eye bank eyes and sighted human eyes, aqueous was exchanged by air, to visualise the posterior corneal surface--that is, the "air to endothelium" interface. Through a 5.0 mm scleral incision, a deep stromal pocket was created across the cornea, using the air to endothelium interface as a reference plane for dissection depth. The pocket was filled with viscoelastic, and an anterior corneal lamella was excised. A full thickness donor button was sutured into the recipient bed after stripping its Descemet's membrane. RESULTS: In 25 consecutive human eye bank eyes, a 12% microperforation rate was found. Corneal dissection depth averaged 95.4% (SD 2.7%). Six patient eyes had uneventful surgeries; in a seventh eye, perforation of the lamellar bed occurred. All transplants cleared. Central pachymetry ranged from 0.62 to 0.73 mm. CONCLUSION: With this technique a deep stromal anterior lamellar keratoplasty can be performed with the donor to recipient interface just anterior to the posterior corneal surface. The technique has the advantage that the dissection can be completed in the event of inadvertent microperforation, or that the procedure can be aborted to perform a planned penetrating keratoplasty.  (+info)

Proteoglycan synthesis by bovine keratocytes and corneal fibroblasts: maintenance of the keratocyte phenotype in culture. (5/726)

PURPOSE: To determine the effect of serum on morphology, growth, and proteoglycan synthesis by primary cultures of collagenase-isolated bovine keratocytes. METHODS: Keratocytes were isolated from bovine corneas using sequential collagenase digestion and cultured in Dulbecco's modified Eagle's medium (DMEM), with and without fetal bovine serum (FBS). Proteoglycans synthesized by the cells in culture and by keratocytes in intact cornea culture were metabolically radiolabeled with 35SO4. The proteoglycans were characterized by their sensitivity to keratanase, chondroitinase ABC, and heparatinase and by their size on Superose 6 HR. Cell number was determined by measuring DNA content of the culture dishes. RESULTS: Keratocytes cultured in 10% FBS proliferated, appeared fibroblastic, and synthesized only 9% of the total glycosaminoglycan as keratan sulfate (KS), whereas cells in serum-free media were quiescent, appeared dendritic, and synthesized 47% KS, a value similar to the 45% KS for corneas radiolabeled overnight in organ culture. This increased proportion of KS synthesis in serum-free media was caused by a moderate increase in KS synthesis combined with a substantial decrease in chondroitin sulfate (CS) synthesis. Fractionation on Superose 6 High Resolution showed the size and relative amounts of the CS- and KS-containing proteoglycans synthesized by keratocytes in serum-free media also more closely resembled that of keratocytes in corneas in organ culture than keratocytes in media containing serum. CONCLUSIONS: A comparison of proteoglycan synthesis and cell morphology between keratocytes in corneas in organ culture and in cell culture indicates that keratocytes maintain a more native biosynthetic phenotype and appearance when cultured in serum-free media. These results also suggest that culturing in the presence of serum fundamentally alters the keratocyte phenotype to an activated cell, mimicking certain changes observed during wound healing.  (+info)

Failure to activate transcription factor NF-kappaB in corneal stromal cells (keratocytes). (6/726)

PURPOSE: Freshly isolated cultures of corneal stromal cells (keratocytes) are incompetent to synthesize the tissue remodeling proteinase, collagenase, in response to agents such as cytochalasin B (CB) or phorbol myristate acetate (PMA), which are strong stimulators of collagenase expression in subcultured fibroblasts of all types, including those from corneal stroma. Incompetence is due to failure to activate an autocrine interleukin (IL)1alpha feedback loop required to mediate cell response. The goal of the present study was to investigate the mechanism for this failure. METHODS: A cell culture model of freshly isolated corneal stromal cells and subcultured stromal fibroblasts from rabbits was used for these studies. RESULTS: Competence to synthesize collagenase in response to CB was acquired as a differentiation property by corneal stromal cells placed in culture, and did not require subculture. Competence acquisition correlated with transition to a fibroblastic spindle shape, assembly of actin stress fibers, and the acquired capacity to collapse in response to CB. It was demonstrated that competence could be more precisely defined as the capacity to express IL-1alpha in response to IL-1, making possible activation of the feedback loop. Investigation into the signaling pathway for IL-1alpha expression in response to IL-1 revealed a requirement for reactive oxygen species and activity of the transcription factor nuclear factor (NF)kappaB. Importantly, freshly isolated stromal cells were found to be relatively incompetent to activate NF-kappaB in comparison to subcultured stromal fibroblasts. CONCLUSIONS: Failure to activate NF-kappaB explains incompetence for expression of IL-1alpha in corneal stromal cells. Because NF-kappaB regulates many cell functions with potential to disturb corneal structure, including expression of inflammatory, stress, and degradative proteinase genes; protection against apoptosis; and cell replication; this seems likely to be an important mechanism protecting corneal stasis and preserving function.  (+info)

Functional human corneal equivalents constructed from cell lines. (7/726)

Human corneal equivalents comprising the three main layers of the cornea (epithelium, stroma, and endothelium) were constructed. Each cellular layer was fabricated from immortalized human corneal cells that were screened for use on the basis of morphological, biochemical, and electrophysiological similarity to their natural counterparts. The resulting corneal equivalents mimicked human corneas in key physical and physiological functions, including morphology, biochemical marker expression, transparency, ion and fluid transport, and gene expression. Morphological and functional equivalents to human corneas that can be produced in vitro have immediate applications in toxicity and drug efficacy testing, and form the basis for future development of implantable tissues.  (+info)

Distribution of ascorbate in the anterior bovine eye. (8/726)

PURPOSE: To analyze the ascorbate distribution in the anterior eye wall to better understand the functional significance of this compound in the eye. METHOD: Ascorbic acid was determined by high-performance liquid chromatography using an LC-10 system (Shimadzu, Kyoto, Japan). Bovine eye samples were used. RESULTS: The highest ascorbate concentration was observed in the corneal epithelium, with significantly higher values in the central (1.56 mg/g) than in the peripheral (1.39 mg/g) area. The ascorbate content was similar in the corneal stroma (0.22 mg/g), the Descemet's membrane (DM)/endothelium (0.22 mg/g), and the aqueous humor (0.21 mg/ml). By comparison, the sclera (0.15 mg/g) and the conjunctiva (0.11 mg/g) showed lower values, as did the lacrimal gland (0.09 mg/g) and the serum (0.0008 mg/ml). CONCLUSIONS: (1) Peak ascorbate concentration was observed in the central corneal epithelium covering the pupillary area. This is compatible with the idea that the ascorbate may act as an UV filter shielding internal eye structures from radiation damage. (2) The ascorbate concentration in the corneal stroma and DM/endothelium was as high as in the aqueous humor, and it is suggested that the aqueous humor plays a key role in the distribution of ascorbate to the anterior eye wall.  (+info)

TY - JOUR. T1 - Quantitative assessment of anteroposterior keratocyte density in the normal rabbit cornea. AU - Petroll, W. M.. AU - Boettcher, K.. AU - Barry, P.. AU - Cavanagh, D.. AU - Jester, J. V.. PY - 1995. Y1 - 1995. N2 - The anteroposterior keratocyte density distribution in the rabbit cornea was measured. Unsectioned tissue blocks from the central cornea of five rabbits were stained with propidium iodide and imaged using a Leica laser scanning confocal microscope. A z-series of images was acquired in each sample, from anterior to posterior stroma in either 3- or 8-μm steps. Software was developed to allow interactive marking of the keratocyte nuclei within each section of the z-series and for calculating cell density. For convenience, cell density was expressed as the number of cells per corneal volume element (CVE), where CVE is a newly defined volume unit with x, y, and z dimensions of 250, 250, and 10 μm, respectively. The calculated keratocyte density was 20.2 ± 1.0 cells/CVE (n ...
The expression of keratocyte- and/or myofibroblast-specific markers and the involvement of VSX1 in wound-healing responses was further investigated in normal and wounded corneas. As expected, wounded corneas showed positive VSX1 staining in the corneal stroma, whereas no signal was observed in normal tissues (Fig. 5) . When VSX1 expression was correlated with CD-34 (keratocyte-specific marker) and α-SMA (myofibroblast-specific marker) expression in normal or wounded corneas, we observed that VSX1 was strongly associated with upregulation of α-SMA and downregulation of CD-34. Normal corneas typically characterized by a quiescent keratocyte population showed high CD-34 (Fig. 6I)expression and barely detectable α-SMA (Fig. 6E)expression, but did not express VSX1 (Fig. 6A) , which is consistent with the presence of a quiescent keratocyte population. In wounded corneas (n = 3) VSX1 expression was strictly correlated with that of α-SMA. Corneas exhibiting increasing values of α-SMA (Figs. 6E 6F ...
The substantia propria (or stroma of cornea) is fibrous, tough, unyielding, and perfectly transparent. At its centre, human corneal stroma is composed of about 200 flattened lamellæ (layers of collagen fibrils), superimposed one on another.[1] They are each about 1.5-2.5 μm in thickness. The anterior lamellæ interweave more than posterior lamellæ. The fibrils of each lamella are parallel with one another, but at different angles to those of adjacent lamellæ. The lamellæ are produced by keratocytes (corneal connective tissue cells), which occupy about 10% of the substantia propria. Apart from the cells, the major non-aqueous constituents of the stroma are collagen fibrils and proteoglycans. The collagen fibrils are made of a mixture of type I and type V collagens. These molecules are tilted by about 15 degrees to the fibril axis, and because of this, the axial periodicity of the fibrils is reduced to 65 nm (in tendons, the periodicity is 67 nm). The diameter of the fibrils is remarkably ...
Purpose : Upon injury to the cornea, the composition of the extracellular matrix (ECM) rapidly changes to promote wound healing through its interactions with integrins. We hypothesize that ECM remodelling occurring during corneal wound healing causes the activation of very specific signal transduction mediators that favor faster closure of the wound. Our goal is to proceed to the pharmacological inhibition and/or activation of the PI3K/Akt mediators Akt and CREB using the human tissue-engineered cornea (hTECs) as a model. Methods : hTECs produced by the self-assembly approach were wounded with a 8-mm diameter biopsy punch and deposited on another reconstructed human corneal stroma to allow wound closure on a natural ECM. Total RNAs and proteins were prepared from the epithelial cells of wounded and unwounded areas and their gene expression pattern was determined by microarrays. The wounded tissues were then incubated with or without C646 (a CREB inhibitor) or with or without SC79 (an AKT ...
De-epithelialised and de-endothelialised bovine corneal stromas with a hydration of 3.2 equilibrated at 154 mM NaCl and buffered at pH 7.4 had their optical density (400-750 nm) measured. Stromas equilibrated against 10, 20, 30, 50 or 100 mM NaCl made isotonic to 154 mM NaCl by supplementing with sorbitol were progressively more transparent as NaCl increased. Hypertonic equilibration against 300, 600 or 1000 mM NaCl resulted in a progressive loss of transparency compared with 154 mM NaCl. Light scattering as a function of wavelength fitted a l_3 function well for 10, 30, 50, 100 and 154 mM NaCl preparations between 450 and 650 nm, but not at higher wavelengths. However, hypertonic 300, 600 and 1000 mM NaCl preparations showed a l_2 dependence in the 450-750 nm range. Experiments with 154 mM NaCl and either 0 or 300 mM sorbitol suggested that the changes in light scattering in hypertonic preparations are unlikely to be caused by osmotic alterations to the stromal keratocytes. Psychophysical ...
Figure 5. TEM of collagen fibrils from mouse corneal stroma. Transmission electron micrographs containing cross-sections of collagen fibrils from corneal stroma from wild-type (A) and mutant (C) mice. Morphometric analysis of corneal collagen fibrils in wild-type (B) and in mutant (D) mice. Fibril diameter was measured as described in methods and presented in a histogram. The average fibril diameter, the variance and the total number (n) of fibrils measured are indicated.. ...
The laboratory mouse is an unsurpassed animal model for studying human diseases due to the abundant availability of mutant species, and the close homology of the human and mouse genomes [14,15]. The physical dimensions of the mouse eye and resulting difficulty in performing manual surgery using conventional instrumentation however complicates accurate ocular surgical models in this animal. In this study we have demonstrated that it is possible to adapt and use a conventional clinical femtosecond laser platform to perform intrastromal lamellar surgery on the mouse eye. The FSL laser causes tissue photo-disruption, which results in the formation of plasma that rapidly expands and collapses, to create an interlamellar (collagen lamellae) cavitation at a precise depth [16]. In the TEM analyses of these cavitations in the mouse cornea we were able to demonstrate distinct localized plasma cavitations with dimensions of ~1 µm. The size of these plasma cavitations is in part related to the energy ...
Data Availability StatementThe datasets used and/or analyzed during the current study are available from your corresponding author on reasonable request. were prepared and subsequently stained with eosin and hematoxylin or antibodies for immunofluorescence observation of human being corneal stroma-related proteins. Results SP marketed the appearance of corneal stroma-related collagens (collagen types I, III, V, and VI) through the differentiation induced by KDM. Patterned silk membrane led cell position of PDLSCs, and essential ECM the different parts of the corneal stroma had been been shown to be transferred with the cells. The built multi-lamellar tissues was found to aid cells developing between every two levels and expressing the primary kind of collagens (collagen types I and V) and proteoglycans (lumican and keratocan) of Clofarabine price Clofarabine price regular individual corneal stroma. Conclusions Multi-lamellar individual corneal stroma-like tissues could be built in vitro by ...
C: Stromal thickness of the Fb was found to be significantly smaller than for ASC in presence of urothelial cells. The UTS of the Fb group was significantly higher compared to the ASC. The failure strains were not significantly different between the two constructions. Tests were performed using 3 different cellular populations (N) for Fbs and ASCs and each construct was produced in triplicate (n). Each column represents mean +/-standard error of the mean, with p,0.05 indicating significance (*p,0.05, ** p,0.005 ...
Herpetic stromal keratitis (HSK) is an immunopathological and tissue destructive corneal lesion caused by herpes simplex virus (HSV) infection, which induces an intense inflammatory response and finally leads to blindness. Accumulating evidence using the murine model has shown that Th-1 phenotype CD4+ T cells orchestrating the inflammation mainly contribute to the immunopathological reaction in HSV-1 infected cornea. However, prior to CD4+ T cell infiltration into corneal lesions, various innate immune cells recruit and produce numerous inflammatory and angiogenic molecules into the corneal stroma those in turn drive the corneal immunopathology. The first part (Part I) of this dissertation focuses on the understanding of HSV-1 induced immunoinflammatory processes in the cornea and trigeminal ganglia including the secondary lymphoid tissues. The next three parts (Part II-IV) focus on different inflammatory and anti-inflammatory mechanisms that are activated following virus infection in the
After corneal injury, keratocytes become activated and transform into repair phenotypes-corneal fibroblasts or myofibroblasts, however, these important cells are difficult to identify histologically, compromising studies of stromal wound healing. Recent studies indicate that expression of the cell surface protein, Thy-1, is induced in fibroblast populations associated with wound healing and fibrosis in other tissues. We investigated whether keratocyte transformation to either repair-associated phenotype induced Thy-1 expression. Human corneal keratocytes were isolated by collagenase digestion. The cells were either processed immediately (i.e. freshly isolated keratocytes) or were cultured in the presence of 10% fetal bovine serum or transforming growth factor-β to induce transformation to the corneal fibroblast and myofibroblast phenotypes, respectively. Thy-1 mRNA and protein expression by freshly isolated keratocytes and corneal fibroblasts were assessed by RT-PCR and Western blotting. mRNA ...
3DBT corneas are comparable to human donor corneas 3DBT corneas are made from human cells, without artificial materials or scaffolds They have the same physical characteristics as the human corneal stroma They can be seen as a direct replacement to donor tissue for anterior keratoplasty
Most studies of herpetic corneal disease use a primary infection model. However, primary infection with HSV-1 does not typically lead...
We measure the surface ablation threshold fluence of porcine corneal stroma for 100 fs laser pulses, with wavelengths between 800 nm and 1450 nm, generated by a Ti:sapphire-pumped optical parametric amplifier. The ablation threshold was found to vary only slightly within this wavelength range, between 1.5 and 2.2 J/cm2. The data suggest a rapid increase of the ablation threshold for wavelengths up to about 1000 nm, followed by a plateau for longer wavelengths. This behavior is partly confirmed by a simple theoretical model of the ablation process. The influence of the wavelength on the physics of surface ablation is discussed on the basis of the model.. ©2008 Optical Society of America. Full Article , PDF Article ...
Corneal collagen crosslinking (CXL) is a minimally invasive procedure that is currently supposed to arrest the progression of corneal ectatic conditions. CXL induces crosslinks in the stromal collagen of the cornea.
An electromechanical model for charged, hydrated tissues is developed to predict the kinetics of changes in swelling and isometric compressive stress induced by changes in bath salt concentration. The model focuses on ionic transport as the rate limiting step in chemically modulating electrical interactions between the charged macromolecules of the extracellular matrix. The swelling response to such changes in local interaction forces is determined by the relative rates of chemical diffusion and fluid redistribution in the tissue sample. We have tested the model by comparing the experimentally observed salt-induced stress relaxation response in bovine articular cartilage and corneal stroma to the response predicted by the model using constitutive relations for the concentration dependent material properties of the tissues reported in a related study. The qualitatively good agreement between our experimental measurements and the predictions of the model supports the physical basis of the model ...
Stromal swelling in human, cat, and rabbit cornea is biphasic, interpretable as an elementary cusp catastrophe proposed by Thom, with t* ═ log t and Q* ═ log Q (stromal charge Q, time t) as control parameters, and H0.5 (hydration H) as the state variable. A thermodynamic potential with two attractor regions, each with a local minimum, governs corneal stromal swelling. Transitions follow a saturation convention whereby the second minimum is preferred upon availability. Corneal swelling is an example of a space-equivalent unfolding, where the transition plane moves in time. It is proposed that the transition plane coincides with the uncoupling of interfibrillary linkages or springs in the corneal stroma, and is associated with a critical hydration of ca. 10 kg H2O per kilogram dry mass, and stromal charge ca. 1 x 10-7 mol electrons. ...
This study evaluates the intrastromal correction of ametropia with a femtosecond laser made by 20/10 PERFECT VISION. This laser generates a beam of ultrashort, infrared pulses which enables very precise cuts in the cornea. By these cuts lamellae of the cornea are separated locally, and in the consequence the curvature of the cornea is changed, and the correction of the diagnosed ametropia can be achieved. On the contrary to cuts which are generated with a sharp knife, the cuts generated when using a laser can be generated just inside the cornea without opening the surface of the cornea. This means the procedure is minimal-invasive.. The study hypothesis is: Different types of ametropia can be corrected safely and on long-term by intrastromal cuts. ...
Xiao-Tang Yin is the author of these articles in the Journal of Visualized Experiments: Recurrent Herpetic Stromal Keratitis in Mice, a Model for Studying Human HSK, Murine Corneal Transplantation: A Model to Study the Most Common Form of Solid Organ Transplantation
With regard to TIMP 3, the total amount of this protein associated with the matrices of confluent stromal cell cultures of normal corneas maintained over a period of time of 8e10 days was approximately 5-fold higher than that within their regularly obtained culture media examples. After infecting stromal cells with RAdTIMP 3 very little of the freshly synthesised TIMP 3 was recovered in their culture media but the quantity connected with the matrices, which was measured 13 days after infection, was significantly more than normally present. Normal corneal stromal cell cultures, when 70-80 Cabozantinib price confluent infected with RAdTIMP 3, all showed symptoms of cell death between day 2 and 5 after infection. As well as the appearance of detached cells in the growth medium, significant pockets developed. As shown in Fig. 3a, these were without both cells and matrix and, because of the unusually dense packing of cells round the holes, appeared to be due to matrix contraction. Eventually ...
The Lasik flap is both an advantage and a disadvantage. Without the Lasik flap (PRK) you have no possibility of a Lasik flap related problem during surgery or your lifetime. Even though Lasik flap problems are relatively rare, no possibility is almost always better than low probability ...
A microkeratome is a precision surgical instrument with an oscillating blade designed for creating the corneal flap in LASIK or ALK surgery. The normal human cornea varies from around 500 to 600 micrometres in thickness; and in the LASIK procedure, the microkeratome creates a 100 to 200 micrometre thick flap ...
There were no statistically significant differences in the thicknesses of pre-ocular tear film, corneal epithelium, Bowman layer, corneal stroma, and Descemets membrane-endothelium complex in the myopic patients and controls (p >0.05). The anterior scleral thickness values of 1 mm, 3 mm, and 5 mm from the limbus were similar in both the study and control groups (p >; 0.05). There were no significant correlations between central cornea stromal thickness and anterior scleral thickness for all the participants (p >0.05 ...
This presentation is from the session SYM-104: Keratoconus: Consensus and Controversy from the 2019 ASCRS Annual Meeting held on May 4-7, 2019 in San Diego, California.. ...
The cornea of the eye is a unique, transparent connective tissue. It is comprised predominantly of collagen fibrils, remarkably uniform in diameter and regularly spaced, organized into an intricate lamellar array. Its establishment involves a precisely controlled sequence of developmental events in which the embryonic cornea undergoes major structural transformations that ultimately determine tissue form and function. In this article, we will review corneal developmental dynamics from a structural perspective, consider the roles and interrelationships of collagens and proteoglycans, and comment on contemporary concepts and current challenges pertinent to developmental processes that result in an optically clear, mature cornea. Developmental Dynamics 237:2607-2621, 2008. © 2008 Wiley-Liss, Inc. ...
It is well understood by oncologists that tumor growth and metastasis depend on changes in the tumor microenvironment or stroma. Stromal changes have been the focus of numerous research publications and have led to insights in both tumor development and promising new avenues for treatment [1-7].. In order to study molecular changes in stroma from tissue samples, it is necessary to separate tumor tissue from stromal tissue. Without this separation we have sample heterogeneity, which is well known to severely limit the conclusions that can be made about the specificity of molecular changes and their biological causes [5, 7-11]. This separation can be difficult in contexts where tumors are small or not well differentiated. For example, in mouse tumor xenograft models, human cancer cells are grown in immune-suppressed mice [12-15]. These models are popular in oncologic research for studying mechanisms of tumor growth and metastasis, as well as drug response. In such studies, secondary tumors (at ...
Intrastromal Rings are inserted inside the cornea to support it. It helps to restore cornea & reduces keratoconus progress. NMC Eyecare offers this treatment.
Lamella of keratocytes generate a small rearward traction force against the micromachined substratum. Bar, 5 μm. Once the lamella of a keratocyte is over the m
Increased mammographic density is associated with increased incidence of breast cancer, and is largely attributed to increased levels of stromal collagen and ch...
Guertin, Inaba T, Propranolol gagueira S, et al. Evidence brought forward at the disciplinary hearing in Lon- don in June 1992 concluded that the same individual probably had provided the samples and that an opportunity had existed for the athletes to catheter- propranolol gagueira urine from another person prior to the sample collection. (a) Immunoglobulin deposits in the corneal stroma appear as red-staining, fusiform structures.
Scientists have developed a new technique to regrow human corneas. Using key tracer molecules, researchers have been able to hunt down elusive cells in the eye
Why are pancreatic tumors so resistant to treatment? One reason is that the wound-like tissue that surrounds the tumors, called stroma, is so dense, likely preventing cancer-killing drugs from reaching the tumor. A team has now discovered heterogeneity in the fibroblast portion of the stroma, opening up the possibility of targeted treatment.
Cornea , Cornea , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی
கருவிழிப் படலம் அல்லது விழி வெண்படலம் (cornea) என்பது கண்ணில் ஒளி ஊடுருவக்கூடிய வட்டவடிவ முன்பகுதியாகும்.[1]விழிவெண்படலத்தில் இரத்த நாளங்களோ அல்லது நிணநீர் நாளங்களோ கிடையாது. இதனால் இரத்த ஓட்டம் இல்லாத இந்த விழி வெண்படலத்திற்கு தேவைப்படும் ஆக்சிசன் மற்றும் உணவுப்பொருட்களை கண்ணின் நடு இரத்த நாள அடுக்கான விழியடி கரும்படலத்தின் முன் பகுதியில் இருக்கும் சிலியரி ...
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The human cornea contains stem cells that can be induced to express markers consistent with multipotency in cell culture; however, there have been no studies demonstrating that human corneal keratocytes are multipotent. The objective of this study is to examine the potential of human fetal keratocytes (HFKs) to differentiate into neural crest-derived tissues when challenged in an embryonic environment. HFKs were injected bilaterally into the cranial mesenchyme adjacent to the neural tube and the periocular mesenchyme in chick embryos at embryonic days 1.5 and 3, respectively. The injected keratocytes were detected by immunofluorescence using the human cell-specific marker, HuNu. HuNu-positive keratocytes injected along the neural crest pathway were localized adjacent to HNK-1-positive migratory host neural crest cells and in the cardiac cushion mesenchyme. The HuNu-positive cells transformed into neural crest derivatives such as smooth muscle in cranial blood vessels, stromal keratocytes, and ...
Cellular therapy of the corneal stroma, with either ocular or extraocular stem cells, has been gaining a lot of interest over the last decade. Multiple publications from different research groups are showing its potential benefits in relation to its capacity to improve or alleviate corneal scars, improve corneal transparency in metabolic diseases by enhancing the catabolism of the accumulated molecules, generate new organized collagen within the host stroma, and its immunosuppressive and immunomodulatory properties. Autologous extraocular stem cells do not require a healthy contralateral eye and they do not involve any ophthalmic procedures for their isolation. Mesenchymal stem cells have been the most widely assayed and have the best potential to differentiate into functional adult keratocytes in vivo and in vitro. While embryonic stem cells have been partially abandoned due to ethical implications, the discovery of the induced pluripotent stem cells (iPSC) has opened a new and very promising field for
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On June 21, 2002, uneventful LASIK was performed OS first followed by OD seven days later on June 28, 2002. There were no intraoperative complications. Excimer laser ablation was performed with a VISX Star S3 IR Excimer Laser System (VISX Technology, California) after a superiorly hinged flap was made with a Hansatome microkeratome (Bausch & Lomb, Rochester, NY) using a 9.5-mm suction ring. A 160 micron Hansatome head was used being that it provided the thinnest available cut at the time of surgery. Intraoperative pachymetry was performed after lifting the flap, taking 3 central measurements, and recording the lowest. The residual stromal bed was calculated by obtaining the lowest central pachymetry and deriving the ablation depth from the laser. In this patient, the targeted flap thickness of 160 micrometers resulted in a measured flap thickness of 124 micrometers OD and 153 micrometers OS, thinner than the corresponding settings on the microkeratome. Hence, the calculated residual stromal bed ...
On June 21, 2002, uneventful LASIK was performed OS first followed by OD seven days later on June 28, 2002. There were no intraoperative complications. Excimer laser ablation was performed with a VISX Star S3 IR Excimer Laser System (VISX Technology, California) after a superiorly hinged flap was made with a Hansatome microkeratome (Bausch & Lomb, Rochester, NY) using a 9.5-mm suction ring. A 160 micron Hansatome head was used being that it provided the thinnest available cut at the time of surgery. Intraoperative pachymetry was performed after lifting the flap, taking 3 central measurements, and recording the lowest. The residual stromal bed was calculated by obtaining the lowest central pachymetry and deriving the ablation depth from the laser. In this patient, the targeted flap thickness of 160 micrometers resulted in a measured flap thickness of 124 micrometers OD and 153 micrometers OS, thinner than the corresponding settings on the microkeratome. Hence, the calculated residual stromal bed ...
TY - JOUR. T1 - Tissue-derived biological particles restore cornea properties in an enzyme-mediated corneal ectatic model. AU - Yin, Hongbo. AU - Wang, Xiaokun. AU - Majumdar, Shoumyo. AU - Sohn, Jeeyeon. AU - Kim, Byung Jin. AU - Stark, Walter Jackson. AU - Elisseeff, Jennifer H.. PY - 2019/12. Y1 - 2019/12. N2 - Purpose: To investigate the impact of tissue derived biological particles on enzyme-mediated weakened corneas. Methods: Rabbit corneas were treated with enzymes to create an ex vivo ectatic model that simulated representative characteristics of keratoconus (KC). Porcine cornea, cartilage, and lymph node tissues were processed to remove most cellular components and cryomilled into microparticles. The KC corneas were cultured in medium containing the tissue-derived biological particles (TDP) overnight. The mechanical, thermal, ultrastructural changes, and gene expressions of corneal stromal cells were characterized to evaluate the effects of the TDP treatment. Results: The enzyme ...
Corneal tattooing is a technique that has been used for centuries to improve either cosmesis or clinically significant anomalies.1 These anomalies include diplopia, glare and halos secondary to peripheral iridotomies (PI), and sector or total iris defects. The most commonly performed tattoo techniques are either by transepithelial intrastromal micropuncture or tattooing the anterior stroma after epithelial debridement.1 2 However, these techniques are known to be associated with several complications, including intra-operative microperforations, recurrent erosions, pigment non-homogeneity and fading of pigment over time.1 2 A newer procedure has been described, termed the intrastromal lamellar pocket technique. Several studies have investigated the use of this technique for aesthetic purposes in non-seeing … ...
The cornea is the primary refractive element of the eye and is also fundamental to the protection of the visual system. Collagen is the major constituent of the cornea, where it is organised in a lattice that enables corneal transparency. Proteoglycan macromolecules are thought to regulate the diameter and spatial order of collagen fibrils in the cornea, which are both pre-requisites for corneal transparency, although the mechanisms by which they organise fibrils are not fully elucidated. This investigation examined the morphology, morphometry and organisation of proteoglycans three-dimensionally, in both normal and genetically altered mouse corneas, to gain a greater understanding of proteoglycan structure-function relationships. In summary, we found that proteoglycans are primarily responsible for the remarkable collagen organisation in the mouse cornea, which allows for corneal transparency. The self- association of proteoglycans into complexes is likely to result in a robust attachment of ...
The cornea is made up of highly organized group of cells and proteins which are arranged in five layers; 1) the corneal ephithelium, which is a multicellular tissue layer of fast-growing and easily-regenerated cells; 2) Bowmans layer, a tough layer which protects the corneal stroma, consisting of irregularly-arranged collagen fibers; 3) the corneal stroma, which is a thick, transparent middle layer, consisting of regularly-arranged collagen fibers along with sparsely populated keratocytes; 4) Descemets membrane, which is a thin but strong sheet of tissue that serves as a protective barrier against infection and injuries; 5) endothelium, the extremely thin, innermost layer of the cornea, consisting of endothelial cells that are essential in keeping the cornea clear. ...
PURPOSE. The authors investigated the phenotypic characteristics of basally located transitional cells in peripheral superior cornea, characterized previously by their coexpression of cytokeratin 19 and vimentin and their negativity for AE5. METHODS. Twenty adult human corneas were studied, using in situ immunohistochemical techniques and a panel of specific monoclonal antibodies against various surface and cytoplasmic molecules. RESULTS. The transitional cells shared staining characteristics with limbal basal cells in their expression of alpha 6 beta 4-integrin, metallothionein, AE1, and transferrin receptor. CONCLUSIONS. These transitional epithelial cells exhibit a unique phenotype differing from that of the surrounding basal epithelial cells in the peripheral cornea but analogous to that of limbal basal cells. These findings further corroborate the hypothesis that, at least from an immunohistochemical point of view, transitional cells in the superior peripheral cornea exhibit stem cell ...
If you or someone close to you has been diagnosed with Keratoconus, you have probably done what most patients have done in the last 10 years. Googled it! When most patients look up their options online, they stumble across a million articles about corneal collagen crosslinking otherwise known as CXL. Now, luckily, the FDA has… Read More » ...
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ReLEx SMILE - Most Advanced Laser Eye Treatment, Beyond LASIK +ACI-Get Rid of your Spectacles in 15 Mins, only at Lotus Eye+ACI ReLEx SMILE (Refractive Lenticule Extraction, SMall Incision Lenticule Extraction) is a minimally invasive approach with advantage of 100+ACU bladeless form of laser eye surgery which does not require
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Magnification: 20X. Sponsored by Zeiss and awarded to an image created using one of its instruments, the award goes to an image by postdoctoral fellow Sarah Robertson and undergraduate researcher Johnson Thai, both from the lab of Dr. Sophie Deng.. The cornea is the transparent front part of the eye that covers the iris and pupil. When the middle layer of the cornea, the cornea stroma, is wounded, the healing process often causes corneal scars that lead to vision impairment. A corneal scratch is seen here (in black) at the center of the image. Collagen 1 (in green), a key player in wound healing, can be seen surrounding the nuclei of cells closest to the scratch.. The Deng lab studies the proteins that are involved in corneal stroma wound healing. They replicate the cellular processes that occur following corneal injury by growing corneal stroma fibroblasts in lab dishes and then scratching them to induce a wound. These studies are being done to inform the development of methods to regenerate ...
If you have had Intacs® and are interested in further options to improve your vision, Dr. Brian, who is one of the most experienced Keratoconus doctors, routinely evaluates patients who have had Intacs® placed elsewhere. Further vision improvement can be an option through 1) Intacs® adjustments for different size, 2) removal (also known as explant) of the upper Intac segment, 3) Holcomb C3-R®, also called corneal crosslinking, to stabilize Keratoconus, and 4) CK (conductive keratoplasty) to improve astigmatism.. If you are considering having Intacs® done by a surgeon other than Dr. Brian, here are some compelling reasons you want to re-think that and have Dr. Brian perform your Intacs®.. ...
Ocular infection with herpes simplex virus 1 (HSV-1) can result in a chronic immuno-inflammatory lesion that is a significant cause of human blindness. IFN-γ producing CD4 + T cells are generally considered the main orchestrators, and lesions are more severe if the regulatory T cell (Treg) response is compromised. Tregs have been shown to lose FoxP3 (Treg lineage factor) and adopt alternate lineage fates in a changing cytokine environment. Moreover, little is known about the stability of Treg cells in an ongoing inflammatory reaction such as is the case of SK. In this study-using fate mapping mice, we were able to demonstrate that the population of ex-Tregs increased at the site of infection that is the cornea and also at the secondary lymphoid organs after HSV-1 infection. In vivo studies showed that these ex-Tregs acquired the Th1 and Th17 phenotype, which may play a destructive role in stromal keratitis. We also demonstrate in vivo that CD25lo subset of Tregs is less suppressive and more ...
TY - JOUR. T1 - Stromal damage in rabbit corneas exposed to CO2 laser radiation. AU - McCally, R. L.. AU - Bargeron, C. B.. AU - Green, W. R.. AU - Farrell, R. A.. PY - 1983/12. Y1 - 1983/12. N2 - Threshold damage to the cornea from CO2 lasers is confined to the epithelium. Exposures well above the threshold for epithelial damage produce bowl-shaped stromal wounds. Light and electron microscopy and slit-lamp photographs all show a sharp demarcation between the damaged and undamaged regions 48 hr after exposure. The micrographs also show that the damaged region is accellular. Calculations of the expected temperature increases combined with analyses of slit lamp photographs show that the wound boundary corresponds to a surface of equal peak temperature increase. Comparisons with epithelial and endothelial damage conditions suggest that stromal, endothelial and epithelial cells have essentially the same thermal damage mechanism.. AB - Threshold damage to the cornea from CO2 lasers is confined to ...
CXL is a unique treatment because it is noninvasive and targets the root of the problem which is the weakened cornea in keratoconus. CXL significantly increases the number of collagen bonds between the corneal layers, in effect returning the cornea to a more stable state. In contrast to other procedures like intrastromal ring segments or laser surgery, only CXL offers the potential to target the underlying cause and thus offer long-term benefits for those suffer from keratoconus.. More interestingly, CXL can be a part of a process in the management of keratoconus patients. It can be combined with Intacs before or after the procedure, and fine tuned with surface laser procedures. ...
PURPOSE: To identify risk factors for opaque bubble layer (OBL) formation and compare the incidence of OBL using a cone modification technique versus the original technique for LASIK flap creation using the VisuMax laser (Carl Zeiss Meditec, Jena, Germany). METHODS: This retrospective study examined videos of flap creation using the VisuMax laser to identify OBL occurrence. Eyes were divided into three groups: eyes where OBL occurred using the original technique (OBL group), eyes where OBL did not occur using the original technique (no OBL group), and eyes in which the cone modification technique was used for LASIK flap creation (larger flap diameter) (cone modification technique group ...
CURRENT RESEARCH GRANTS 1. RO1 Grant from National Institute of Health (NEI). Ocular Mucosal Immunity Induced By HSV1 Lipopeptides. EY14900. September, 30, 2003 to May 31 2012. Principal Investigator: Lbachir BenMohamed. 2. Discovery Eye Foundation. Therapeutic vaccine against ocular herpes in HLA transgenic rabbits.. January, 1, 2009 to December 31 2015. Principal Investigator: Lbachir BenMohamed. 3. RO1 Grant from National Institute of Health (NEI). Role of TGFbeta in Corneal Stromal Wound Healing. EY007348 March, 1st, 2006 to April 31 2011. Co-Investigator (10%): Lbachir BenMohamed. 4. RO1 Grant from National Institute of Health (NEI). Corneal HSV-1: Immunopathologic Mechanisms of HSK. EY018171. January, 1st, 2008 to December 31 2010. Co-Investigator (10%): Lbachir BenMohamed. 5. R24 Core grant from National Institute of Health (NEI). Vision Research Infrastructure Development. EY016663. June 1, 2005-May 31, 2010. Co-Investigator, Director of Cell Culture Module (5%): Lbachir BenMohamed. 6. ...
Introduction and Background. The cornea remains transparent for many reasons. But the reason it is important to understand what is happening in a blue eye is that in a normal cornea, the collagen fibrils that make up the corneal stroma are uniformly spaced in a configuration that allows visible light to go through. While other tissues in the body have higher water contents, the cornea is only 78% water. This allows the collagen fibrils to maintain their optimal spacing. When excess water enters the cornea, it increases the space between the corneal fibrils, causing a wavelength-dependent decrease in light transmission through the cornea. This wavelength-dependent decrease is why the cornea not only turns cloudy when it is edematous, but it acquires a blueish hue as well.. As the cornea is surrounded by water (the tear film in front and the aqueous humor behind), the cornea must work very hard to regulate the water levels within its stroma. The outermost cells of the corneal epithelium have ...
A team of outstanding surgeons from all over the world who have made recent major advances in the management and treatment of Keratoconus, have shared their invaluable experiences in this book. Each one of them is a brilliant medical writer as well; the quality which is not commonly found. Includes latest techniques which were expressly ideated to strengthen or to replace a weakened corneal stroma. Collagen cross-linking may prove to be very effective in the management of Ectasia. ...
The mice were adminstered doxycycline (2 mg/mL) for seven days in the drinking water with 5% sucrose or with 9-t-butyl doxycycline at (02 and 2 mg/mL). When this LH surge reaches a certain point, bentyl price one of your ovaries releases an egg? Por lo tanto, interim himcolin gel price in india hindi Augmentin Bid jarabe 457 mg/5 ml posee las propiedades distintivas de un antibiótico de amplio espectro y un inhibidor de la beta-lactamasa. โรคซึมเศร้า เริ่มต้นด้วยขนาด 25-50 มกต่อวัน แล้วค่อย ๆ ปรับเป็นวันละ 150 มก. I would stop using Retin A for two days before the facial and for two days after. So my dermatologist perscribed retin a to help with sun damage and the lines! The results of this study were consistent with previous HEDS data showing that patients with a history of ocular HSV not affecting the corneal stroma rarely experience episodes of HSV stromal keratitis later? ...
RESULTS: The receptors for LXA4, ALX/Fpr-rs-2 and for RvE1, ChemR23 were each expressed by epithelium, stromal keratocytes, and infiltrated CD11b(+) cells in corneas. Compared to the vehicle-treated eye, ATLa-, RvD1-, and RvE1-treated eyes had reduced numbers of infiltrating neutrophils and macrophages and reduced mRNA expression levels of TNF-alpha, IL-1 alpha, IL-1 beta, VEGF-A, VEGF-C, and VEGFR2. Animals treated with these mediators had significantly suppressed suture-induced or IL-1 beta-induced hemangiogenesis (HA) but not lymphangiogenesis. Interestingly, only the application of ATLa significantly suppressed VEGF-A-induced HA ...
The analysis of the stress-strain curves showed a different corneal response between treated (TS) and untreated (CS) samples. TS showed a stiffer behaviour than CS. The treated corneal tissue (TS) resulted 1.8, 1.6, 1.7 and 1.5 fold stiffer than the untreated sample (CS) at 6, 8, 10 and 12% stretch, respectively. The histological analysis of TS showed an increased fibrillar density with decrease of interlamellar space in comparison with CS. Keratocyte apoptosis was observed in TS even at deep stromal level. There is an evident absence of nuclei in the treated sample compared to the control. Interlamellar spaces correspond to the presence of a cellular body, but the nucleus could not be present at the depth of the tissue section ...
Spontaneous symmetry breaking and motility initiation of keratocytes. Phase-contrast time-lapse video of a keratocyte spontaneously breaking symmetry ...
Keratoconus treatment for age above 45 years includes intacs, PIE, toric lens and c3R. Expert keratoconus surgeon can decide best option for your lifestyle.
Corneal inlays to correct refractive errors are not new-various materials have been tried for more than 50 years to correct blurred vision. The greatest barriers to success of corneal inlays have been a lack of biocompatibility with the cornea, the difficulty of placing them within the corneal stroma safely, and refractive predictably. ...
Birk, D E et al Collagen type I and type V are present in the same fibril in the avian corneal stroma.. The Journal of Cell Biology 106.3 (1988): 999-1008. Web. 16 Jan. 2018. ...
Very impressive attention to texture, lighting, and details. What software did you use to create these? It looks amazing! 7 years ago ...
3D printing is bringing ideas and images into the third dimension; being used in engineering and scientists have used the technology to print the first corneas.
second wave of migratory cells containing presumptive keratocytes invades the matrix, leading to formation of inner cornea and outer cornea. A unique cell mass (stroma attracting center) connects the two layers like the center pole of a tent ...
The cornea is the windshield through which you see the world. It is composed of collagen and different layers of transparent cells on the outermost part of the eye. Sometimes things can happen to the cornea, it can become badly scarred, thinned out or cloudy due to disorders of the cornea or due to injury. This can dramatically reduce your…
GPI 2780 Cornea Eye Cross-Section Model is a normal oversized eye model includes 4 interchangeable corneas that show various cornea conditions.
Cornea, the transparent layer of eye refracts light onto the lens. Dr. Agarwals Cornea Foundation offers comprehensive treatment for all cornea diseases.
Cornea surgery has developed rapidly over the last few years, with techniques that were unthinkable just a few years ago becoming increasingly commonplace. Examine the latest techniques in the field together with the Asia Cornea Society.. ...
Televiziunea Cornea TV emite deocamdata doar pe internet, solicitarea pentru licența depusa in aprilie 2018 la CNA fiind respinsa. Fanii emisiunii La Hanu lu Nea Mărin, difuzata pana in 2018 de Inedit TV, vor putea urmari show-ul preferat numai aici, la Cornea TV ...
As light enters the transparent cornea, the cornea bends the light rays. This is the first step in the focusing process, which projects a coherent im...
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MOLA HIDATIDOSA Ibu Reni A.Defenisi • Mola hidatidosa ialah kehamilan abnormal, dengan ciri-ciri stroma vilus korialis langka vaskularisasi, dan ...
The corneal stroma becomes severely disorganised; the lamellar arrangement of the fibrils becomes disrupted.[citation needed] ... Congenital hereditary corneal dystrophy (CHED) is a form of corneal endothelial dystrophy that presents at birth. CHED was ... Posterior polymorphous corneal dystrophy (for the condition previously referred to as CHED1) Corneal dystrophy Bowes Hamill, M ... Management of CHED primarily involves corneal transplantation. The age that corneal transplantation is required is variable, ...
Corneal epithelium suffered abrasions and stroma were punctured. There was also an infestation during the 1997-1998 summer and ...
Goodfellow, Julia (1975). Structural studies of the corneal stroma (PhD thesis). Open University. Goodfellow profile at the ...
Shimazaki, J; Harashima, A; Tanaka, Y (9 October 2009). "Corneal endotheliitis with cytomegalovirus infection of corneal stroma ... "Mapping owl's eye cells of patients with cytomegalovirus corneal endotheliitis using in vivo laser confocal microscopy". ...
"Synchrotron X-ray diffraction study of corneal stroma". Journal of Molecular Biology. 160 (4): 593-607. doi:10.1016/0022-2836( ... "Interpretation of the meridional X-ray diffraction pattern from collagen fibrils in corneal stroma". Journal of Molecular ...
In the examination of biomicroscopy, it appears as branches spread on the corneal stroma in the appearance of ghost vessels. ... Lattice corneal dystrophy type is a rare form of corneal dystrophy. It has no systemic manifestations, unlike the other type of ... Amyloid deposits are found throughout the corneal stroma. Linear and other shaped opaque areas accumulate particularly within ... the central corneal stroma, while the peripheral cornea remains relatively transparent.[citation needed] In case of corneal ...
During development of the embryo, the corneal stroma is derived from the neural crest (a source of mesenchyme in the head and ... At its centre, human corneal stroma is composed of about 200 flattened lamellæ (layers of collagen fibrils), superimposed one ... "Mesenchymal stem cells in the human corneal limbal stroma". Invest Ophthalmol Vis Sci. 53 (9): 5109-16. doi:10.1167/iovs.11- ... The stroma of the cornea (or substantia propria) is a fibrous, tough, unyielding, perfectly transparent and the thickest layer ...
... corneal stroma or the dental pulp of deciduous (baby) teeth. The cells do not have the capacity to reconstitute an entire organ ... "Mesenchymal stem cells in the human corneal limbal stroma". Investigative Ophthalmology & Visual Science. 53 (9): 5109-16. doi: ... "Isolation and characterization of human clonogenic osteoblast progenitors immunoselected from fetal bone marrow stroma using ...
March-April 1995). "Refractive index of the human corneal epithelium and stroma". J Refract Surg. 11 (2): 100-105. doi:10.3928/ ...
Neutrophils infiltrate the corneal stroma in a diffuse, multifocal pattern. Infiltration is confined to the surgical flap ... DLK can also occur following myopic keratomileusis, in which a disc of corneal tissue is removed, shaped and sutured back into ...
Quantock, A.J. and R.D. Young, Development of the corneal stroma, and the collagen-proteoglycan associations that help define ... Hamrah, P., et al., The corneal stroma is endowed with a significant number of resident dendritic cells. Invest Ophthalmol Vis ... Keratocytes are flattened cells found dispersed within the corneal stroma. The primary role of this sparse population of cells ... Corneal nerves serve as a form of defense by detecting the presence of foreign bodies on the corneal surface. This leads to ...
The corneal stroma consists of approximately 200 layers of mainly type I collagen fibrils. Each layer is 1.5-2.5 μm. Up to 90% ... Corneal pachymetry Corneal reflex Corneal tattooing Corneal topography Eye disease Keratometry List of keratins expressed in ... If the corneal stroma develops visually significant opacity, irregularity, or edema, a cornea of a deceased donor can be ... Corneal stroma (also substantia propria): a thick, transparent middle layer, consisting of regularly arranged collagen fibers ...
Macular corneal opacity is a semidense opacity produced when scarring involves about half the corneal stroma. Leucomatous ... The term corneal blindness is commonly used to describe blindness due to corneal opacity. Depending on the density, corneal ... Corneal transplantation Corneal ulcer Corneal button "WHO -Priority eye diseases". www.who.int. Archived from the original on ... Femtosecond laser-assisted corneal tattooing: Femtosecond laser-assisted corneal tattooing is a new corneal tattooing technique ...
... s (corneal fibroblasts) are specialized fibroblasts residing in the stroma. This corneal layer, representing ... As soon as the basement membrane of corneal epithelium is restored, TGF beta inflow into the stroma drastically decreases and ... Corneal crystallins, like the lens ones, are thought to help maintain the transparency and optimal refraction. They are also ... MACULAR DYSTROPHY, CORNEAL, 1; MCDC1 - OMIM. Patel S, McLaren J, Hodge D, Bourne W (February 2001). "Normal human keratocyte ...
These occur because descemet's membrane is less elastic than the corneal stroma. Tears are usually peripheral, concentric with ...
These infectious agents produce proteases and collagenases which break down the corneal stroma. Complete loss of the stroma can ... The epithelium sticks to the basement membrane, which also separates the epithelium from the stroma. The corneal stroma ... Posterior to the stroma is Descemet's membrane, which is a basement membrane for the corneal endothelium. The endothelium is a ... Melting ulcers are a type of corneal ulcer involving progressive loss of stroma in a dissolving fashion. This is most commonly ...
"The corneal stroma is endowed with a significant number of resident dendritic cells." Investigative Ophthalmology & Visual ... Hamrah P, Liu Y, Zhang Q, Dana MR (February 2003). "The corneal stroma is endowed with a significant number of resident ... "Corneal immunity is mediated by heterogeneous population of antigen‐presenting cells." Journal of Leukocyte Biology 74, no. 2 ( ... "Novel characterization of MHC class II-negative population of resident corneal Langerhans cell-type dendritic cells." ...
"BMP7 gene transfer via gold nanoparticles into stroma inhibits corneal fibrosis in vivo". PLOS ONE. 8 (6): e66434. Bibcode: ... Corneal haze in rabbits have been healed in vivo by using polyethylemnimine-capped gold nanoparticles that were transfected ... with a gene that promotes wound healing and inhibits corneal fibrosis. Toxicity in certain systems can also be dependent on the ...
These infectious agents produce proteases and collagenases which break down the corneal stroma. Complete loss of the stroma can ... which is taken up by exposed corneal stroma and appears green, helps in defining the margins of the corneal ulcer, and can ... Melting ulcers are a type of corneal ulcer involving progressive loss of stroma in a dissolving fashion. This is most commonly ... Deep ulcers extend into or through the stroma and can result in severe scarring and corneal perforation. Descemetoceles occur ...
... is corneal scarring due to chronic inflammation of the corneal stroma. Interstitial means space between cells i.e. corneal ... The corneal scarring is the end result of the initial invasion of blood vessels into the corneal stroma as part of the ... Since normal corneal tissue should be avascular (no blood vessel) and therefore clear to allow light to pass, the presence of ... Keratitis means corneal inflammation. Acutely, early symptoms include a painful, photophobic, red watery eye. This is due to ...
"Acquisition of type IX collagen by the developing avian primary corneal stroma and vitreous". Dev. Biol. 128 (2): 396-405. doi: ...
AS is caused by leakage of lipoproteins from limbal capillaries into the corneal stroma. Deposits have been found to consist ... It is the most common peripheral corneal opacity, and is usually found in the elderly where it is considered a benign condition ... Limbus sign is caused by dystrophic calcification at the corneal limbus, and can be confused with AS in geriatric populations. ... Chambless LE, Fuchs FD, Linn S, Kritchevsky SB, Larosa JC, Segal P, Rifkind BM (October 1990). "The association of corneal ...
He would then apply the ink into the anterior corneal stroma with each puncture. Samuel Theobald would inject the eye first ... Corneal opacities are the leading reason for undergoing cosmetic tattooing. The leading reason for corneal tattooing is to ... "Corneal Tattooing." British Journal of Ophthalmology. 1461. Theobald, Samuel. "A Practical Point in the Technic of Corneal ... "Corneal tattooing to mask subsequent opacification after amniotic membrane grafting for stromal corneal ulcer." Acta ...
Nodule formation can also occur when the abnormal corneal endothelium causes contractions around the iris stroma. Herpesvirus ... On exam patients have normal to decreased visual acuity, and a "beaten metal appearance" of the corneal endothelium, corneal ... The exact mechanism is unknown, however there appears to be a component of abnormal corneal endothelium that proliferates onto ... Other features include possible mild iris changes, corneal edema, and normal to slight elevations in intraocular pressure. ...
The extracellular mesenchyme forms the sclera, the corneal endothelium and stroma, blood vessels, muscles, and vitreous. The ... Surface ectoderm produces the following parts: lens corneal epithelium skin of eyelid Neural crest cells are themselves derived ... Surface ectoderm forms the lens, corneal epithelium and eyelid. ... Bowman's membrane and stroma According to Liem et al., the ...
When this happens, the blade inadvertently cuts into the collagenous corneal stroma and creates an irregularity. If this ... Less damage to corneal nerves, hence safer in dry eyes If cornea is abnormal for LASIK, epilasik may still be an option ... Chen WL.Bilateral complicated stromal dissections during mechanical epikeratome separation of the corneal epithelium.J Refract ... of cases is corneal stromal incursion during the microkeratome pass. ...
Their further investigation of this pre-Descemet stroma confirms that it is stroma, and not a new corneal layer...[D]espite ... Their further investigation of this pre-Descemet stroma confirms that it is stroma, and not a new corneal layer. "Scientists ... The images showed a thin layer of corneal collagen between the corneal stroma and Descemet's membrane. The findings were ... During surgery, tiny air bubbles are injected into the corneal stroma in what is known as the "big bubble technique". Sometimes ...
The healing corneal wounds consist of newly abutting corneal stroma, fibroblastic cells, and irregular fibrous connective ... Incisions that penetrate only the superficial corneal stroma are less effective than those reaching deep into the cornea, and ... Other sources cite surgeries leaving 20 to 50 micrometres of corneal tissue unincised (roughly equivalent to 90% of corneal ... Presbyopia Cataracts Corneal scars Corneal instability (thin/ectasia/trampoline effect) The PERK study demonstrated that people ...
... slowly progressive thinning of the peripheral corneal stroma. Usually diagnosed clinically by several clinical tests. Although ... corneal collagen cross-linking to strengthen a weak and ectatic cornea, or corneal transplant for advanced cases. "Corneal ... Corneal topography Corneal tomography Treatment options include contact lenses and intrastromal corneal ring segments for ... Corneal ectatic disorders or corneal ectasia are a group of uncommon, noninflammatory, eye disorders characterised by bilateral ...
... slowly progressive thinning of the peripheral corneal stroma. The cause of Terrien marginal degeneration is unknown, its ...
The corneal endothelial cells normally do not undergo mitotic cell division, and cell loss results in permanent loss of ... When endothelial cell counts drop too low, the pump starts failing to function and fluid moves anterior into the stroma and ... "Descemet's membrane endothelial keratoplasty versus Descemet's stripping automated endothelial keratoplasty for corneal ...
These cells lead to formation of most of the anterior segment structures of the eye (corneal stroma & endothelium, iris stroma ... refers to a spectrum of diseases characterized by malformations of the irido-corneal angle of the anterior chamber of the eye. ...
The second was using Nomarski optics to study how corneal fibroblasts migrated through the stroma in vivo and in collagen gels ... They cultured corneal epithelium in all types of ECM and were able to show that the ECM can induce cell differentiation and ... They used avian corneal epithelium rather than salamander epidermis in order to provide more examples of epithelium secreting ... The first was on corneal endothelium morphogenesis and they, with Sam Meller, showed that the key constraint on migration was ...
The corneal epithelial layer is generally removed to increase penetration of the riboflavin into the stroma, a procedure known ... Corneal cross-linking with riboflavin (vitamin B2) and UV-A light is a surgical treatment for corneal ectasia such as ... Corneal Collagen Cross-Linking on National Keratoconus Foundation website. Corneal Collagen Cross-Linking on EyeWiki from the ... "Corneal collagen crosslinking: A clinical update". "Corneal cross-linking" (PDF). Moorfields Eye Hospital NHS Foundation Trust ...
... appears at first glance to be poor for ocular health since heparanase release from invading lymphocytes in the corneal stroma ... Both corneal fluorescein staining and the symptom of burning/stinging were reduced. In keeping with a biphasic dose response, ... Also down regulated are tear lipocalin-1 and cystatin S. Fungal keratitis accounts for half of all corneal ulcers in Africa and ... Whitcher JP, Srinivasan M (Aug 1997). "Corneal ulceration in the developing world--a silent epidemic". Br J Ophthalmol. 81 (8 ...
... and at 10 years follow-up there was still no evidence of the inclusions in the stroma. Klintworth GK (2009). "Corneal ... Fleck corneal dystrophy, also known as Francois-Neetens speckled corneal dystrophy, is a rare form of corneal dystrophy. It is ... Small opacities, some of which resemble "flecks", are scattered in the stroma of the patients. Other opacities look more like ... In a single case report, a corneal transplantation was performed for concurrent keratoconus, ...
... stretch reflex striae gravidarum stria medullaris thalami stria terminalis striate cortex striate nucleus striatum stroma ... contralateral conus elasticus conus medullaris Coracobrachialis muscle coracoid coracoid process cordotomy cornea corneal ...
Arc-scanning very high-frequency ultrasound for 3-D pachymetric mapping of the corneal epithelium and stroma in laser in situ ... 3-D scans of the cornea that allowed measurement and mapping of corneal thickness as well as the thickness of the stroma and ... Corneal pachymetric topography. Ophthalmology 101:432-438, 1994. Reinstein DZ, Silverman RH, Raevsky T, Simoni GJ, Lloyd HO, ... This system allowed demonstration of the importance of arc-scanning for corneal analysis and led to the subsequent development ...
Corneal epithelial infiltrates Keratitis Corneal ulcer Corneal stroma Corneal neovascularisation Corneal oedema Corneal ... Ptosis Giant papillary conjunctivitis Superior limbic keratoconjunctivitis Epithelium Corneal abrasion Corneal erosion Contact ... infiltrates Corneal endothelium Endothelial polymegathism Effects of long-term contact lens wear on the cornea (Articles ...
... scientists in China described a CRISPR-Cas9 genome editing approach which could be used to treat HSV-1 in corneal stroma: ...
The brush contains a small burr that is capable of penetrating an eye's corneal stroma to reach small foreign objects lodged in ...
Pericytes present in the stroma of tumors of breast cancer patients express MMP-9. Animal models deficient of MMP-9 display ... Kato, T; Kure, T; Chang, JH; Gabison, EE; Itoh, T; Itohara, S; Azar, DT (2001). "Diminished corneal angiogenesis in gelatinase ... Both enzymes inhibit bFGF induced vascularization in the corneal pocket assay and inhibit VEGF induced angiogenesis in the ... For example, MMP-2 knockout mice develop normally but display significant inhibition of corneal angiogenesis. Numerous ...
... has potent angiogenic activity upon endothelial cells and induces neovascularization, first demonstrated in a corneal ... "CYR61 and αVβ5 Integrin Cooperate to Promote Invasion and Metastasis of Tumors Growing in Preirradiated Stroma". Cancer Res. 68 ...
A similar result was produced in the corneal micropocket assay, where FGF-2 is implanted into the cornea of mice and in normal ... Cathepsin S is a potential protease that acts on the core protein of perlecan in the basement membrane or stroma. The heparan ... Corneal opacification occurred in both transgenic lines early in development due to greatly increased expression of perlecan, ... Li W, He H, Kuo CL, Gao Y, Kawakita T, Tseng SC (June 2006). "Basement membrane dissolution and reassembly by limbal corneal ...
The condition can cause oedema of the surrounding tissue, including the stroma, and can cause irritation and pain. If it is ... "Mumps-Induced Corneal Endotheliitis" 2004 Cornea Chee, Soon-Phaik; Bacsal, Kristine; Jap, Aliza; Se-Thoe, Su-Yun; Cheng, Ching ... "Experimental Corneal Endotheliitis in Rabbits" 2000 Association for Research in Vision and Ophthalmology Singh, Kirti " ... Li; Tan, Ban Hock (2007). "Corneal Endotheliitis Associated with Evidence of Cytomegalovirus Infection". Ophthalmology. 114 (4 ...
In the reactive stroma hypothesis, tumor cells cause the proliferation of fibroblasts and subsequent secretion of collagen. The ... "Mosaic analysis of stem cell function and wound healing in the mouse corneal epithelium". BMC Developmental Biology. 9: 4. doi: ... A diagnosis of reactive stroma associated with prostate cancer is one of poor prognosis. Clinical presentation of a lump in the ... As such, the surrounding stroma plays a very important role in the progression of cancer. The interaction between cancer cells ...
Corrocher R, Tedesco F, Rabusin P, De Sandre G (February 1975). "Effect of human erythrocyte stromata on complement activation ... a blindness disease of the corneal limbus) while ABCB5- cells could not, indicating a therapeutic potential for treating some ... "ABCB5 is a limbal stem cell gene required for corneal development and repair". Nature. 511 (7509): 353-7. doi:10.1038/ ...
... a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium. The outer layer of ... With PRK, the corneal epithelium is removed and discarded, allowing the cells to regenerate after the surgery. The procedure is ... The amount of corneal hazing after surgery is also decreased with brush technique. The platelet activating factor LAU-0901 has ... Uncomplicated, successful corneal refractive surgery does not require a waiver and is noted as information only. The Navy and ...
... the most common injuries seen in this zone are foreign debris retention by the conjunctiva or corneal epithelium/stroma, as ... Application of the Seidel Test in Zone I will rule out seepage of the anterior chamber through a corneal perforation, while ... The Seidel test may be used to evaluate the status of the anterior chamber, thereby determining the presence of corneal ...
... a 15 micron thick layer between the corneal stroma and Descemet's membrane, Harminder Dua suggests that this finding will ... Corneal hydrops is an uncommon complication seen in people with advanced keratoconus or other corneal ectatic disorders, and is ... Corneal transplantation is not usually indicated during corneal hydrops. The person experiences pain and a sudden severe ... and understanding of corneal dystrophies and pathologies, such as acute hydrops. "Acute Corneal Hydrops". University of ...
When used in corneal surgery, picosecond and nanosecond disruptors are used on the lamellae of the corneal stroma, and the ... This modifies the outer corneal curvature, which affects the refractive property of the eye. Fankhauser, Franz; Kwasniewska, ...
This rapid coagulation produces a temporary framework so the fibrous stroma can be regenerated by host cells. Collagen based ... collagen films act like a barrier membrane and are used to treat tissue infections like infected corneal tissue or liver cancer ...
... corneal endothelium and keratocytes, trabecular cells, ciliary epithelium, and conjunctival and iridal stroma cells, and ... a reduction in the levels of Vascular endothelial growth factor and matrix metalloproteinase-9 expression in the tumor's stroma ...
Rieger H. Contributions to the knowledge of rare malformations of the iris II: hypoplasia of the iris stroma with dislocation ... The most characteristic feature affecting the eye is a distinct corneal posterior arcuate ring, known as an "embryotoxon". In ... This primordial endothelium also generates an excessive and atypical basement membrane, especially near the limbal corneal ... Lubin, J. R. (1981). Oculocutaneous Albinism Associated with Corneal Mesodermal Dysgenesis. American Journal of Ophthalmology, ...
Meek, KM; Knupp, C (2015). "Corneal structure and transparency". Prog Retin Eye Res. 49: 1-16. doi:10.1016/j.preteyeres.2015.07 ... glass and liquids as well as the collagen fibrils of the stroma in the cornea. Besides ordering of atoms, short-range ordering ...
An abnormality of the stroma of cornea, also known as the substantia propria of cornea. ... Corneal stromal edema. 0. Opacification of the corneal stroma +. 0. Posterior corneal stroma punctiform multicolored opacities ...
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"Cellular Changes of the Corneal Epithelium and Stroma in Herpes Simplex Keratitis." Ophthalmology 119 (9) (September): 1791- ... Cellular Changes of the Corneal Epithelium and Stroma in Herpes Simplex Keratitis. ... Changes were correlated to corneal sensation, number of nerves, and total length of nerves. Results There was a significant and ... To analyze the morphology of corneal epithelial cells and keratocytes by in vivo confocal microscopy (IVCM) in patients with ...
It occurs because of a disruption in the integrity of the corneal epithelium or because the corneal surface scraped away or ... Corneal abrasion is probably the most common eye injury and perhaps one of the most neglected. ... or poor healing may result in irregularity of the corneal epithelium or scar formation within the stroma. ... Adverse corneal events, such as corneal abrasions, have been reported with techniques of overnight corneal reshaping with ...
... the corneal stroma and then utilized morphometric studies to compute the specific hydraulic conductivity of the corneal stroma ... Specific Hydraulic Conductivity of Corneal Stroma as Seen by Quick-Freeze/Deep-Etch Darryl Overby, Darryl Overby ... Our studies demonstrated ultrastructural elements of the extracellular matrix of the corneal stroma that are not seen using ... A Synchroton X-Ray Study of the Changes Occurring in the Corneal Stroma During Processing for Electron Microscopy ...
In en face views the bands criss-crossed in the posterior stroma except in keratoconus where they tended to run parallel. OCT- ... The role of these soft, elastic regions of collagen 6A1 linking sets of collagen lamellae may be to maintain corneal shape ... these dark bands depart from anchor points at Descemets membrane in the posterior stroma obliquely in a V-shape, whereas in ... and their visibility is enhanced in pathologies where corneal shape is under stress. Methods : : Images of 24 normal and 47 ...
The stroma accounts for approximately 90% of the total corneal volume. It is ... separating the corneal epithelium from the stroma. It is usually 10-17 µm ... Corneal and epithelial thickness changes after 4 weeks of overnight corneal refractive therapy lens wear, measured with optical ... pump which removes fl uid by active transport from the corneal stroma to ...
Clinical observation of corneal stroma injection of different concentrations of fluconazole for fungal keratitis. August 31, ... Corneal stroma fluconazole injection is an effective method for treatment of fungal keratitis.In order to reduce the occurrence ... This study was to observe the clinical effects of corneal stroma fluconazole injection with different concentration for the ... injecting antifungal drugs to the corneal stroma not only enrich the treatment of the disease, but also achieve good clinical ...
Tissue engineering of the cornea: orthogonal scaffold of magnetically aligned collagen lamellae for corneal stroma ... orthogonal scaffold of magnetically aligned collagen lamellae for corneal stroma reconstruction ...
ep., corneal epithelium, mela, melanocyte, cor. str., corneal stroma, TM, trabecular meshwork, PE/NPE, ciliary (non) pigmented ... The distribution of putative TM cells between clusters 11 (corneal endothelium-like), 14 (corneal stroma/fibroblast) and 15/16 ... suggesting that these may represent the Cd34-positive corneal stroma population which has been previously described38. However ... Cluster 11 contained Cdh2-positive cells hypothesized to be corneal endothelium as well as Acta2-positive cells expressing ...
Categories: Corneal Stroma Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, CopyrightRestricted 2 ...
Figure 4-4 A break in Descemet membrane in keratoconus shows anterior curling of Descemet membrane toward the corneal stroma ( ...
... corneal abnormalities), there are other conditions that warrant caution (e.g., excessively dry eyes, contact lens intolerance, ... chronic pain syndromes). Postoperative dry eye, which may in part represent a corneal neuropathy, usually resolves after six to ... which reshape the corneal stroma using laser energy, have been marketed as simple and safe alternatives to glasses or contact ... The central stroma is made up of layers of collagen and accounts for 90% of overall corneal thickness. It also provides most of ...
Orthogonal scaffold of magnetically aligned collagen lamellae for corneal stroma reconstruction. Biomaterials. (2007) 28:4268- ...
To understand the significance of new imaging techniques, the relevant principles of corneal optics are reviewed. ... Stroma: The corneal stroma is composed of a combination of keratocytes, collagen, and amorphous ground substance. All 3 of ... Corneal Shape. The average anterior and posterior corneal power is 48.6 diopter (D) and -6.8 D, respectively. To simplify it in ... Limitations of corneal topography: The error of corneal topography is under optimal conditions in the range of ±0.25 D or 2-3 ...
Propagation of infrared wavelengths through the corneal stroma with reference to hydration changes. Presented at: Saratov Fall ... Propagation of infrared wavelengths through the corneal stroma with reference to hydration changes. Presented at: Saratov Fall ...
Corneal modification procedures may eliminate the need for eyeglasses or contact lenses or reduce the power of a prescription. ... in the midperipheral corneal stroma to flatten the radius of curvature. Intrastromal corneal ring segments are currently being ... The laser utilizes a 193 nm argon-fluoride beam to reshape the anterior corneal stroma by breaking collagen bonds and expelling ... Radiofrequency energy is delivered through a fine tip inserted into the corneal stroma. The collagen lamellae in the area ...
Opacification of the corneal stroma. 77 / 7739 42. (HPO:0000369) Low-set ears. 372 / 7739 ...
"Interestingly, the structure of collagen fibrils in fish scale is very similar to that of human corneal stroma," says Ikoma. " ... "So the investigation of fish scale will be useful for the reconstruction of corneal stroma." ...
Scattered T-lymphocytes also were seen in the peripheral corneal stroma and epithelium in animals with corneal ... we noted patchy IHC staining in the corneal endothelium deep to Descemets membrane. In 2 animals (Jos-1 and -9), patchy but ... Inflammation rarely extended into the stroma of the iris. Another prominent feature in 6 of 9 animals that died of LASV ... although the pyknotic debris and swollen endothelium in the new vessels at the corneal margin in LASV-infected guinea pigs ...
Daxer, A.; Fratzl, P.: Collagen fibril diameter in the human corneal stroma. In Investigative Ophthalmology and Visual Science ... Daxer, A.; Fratzl, P.: Quantitative characterisation of the structural anisotropy in the human corneal stroma. In Investigative ...
Axelsson, I. & Heinegård, D. (1980). Characterization of chondroitin sulfate-rich proteoglycans from bovine corneal stroma.. ... Axelsson, I. & Heinegard, D. (1978). Characterization of keratan sulphate proteoglycans from bovine corneal stroma. Biochemical ... Dahl, I. & Axelsson, I. (1980). The inhibition by retinoic acid of the biosynthesis of proteoglycans in corneal cell cultures. ... Axelsson, I. (1978). Biology of corneal and skeletal proteoglycans. I Biochimie des tissus conjonctifs normaux et pathologiques ...
Sudanophilic lipid deposits in Descemet membrane, Bowman zone and in a wedge-shaped portion of the peripheral corneal stroma. ... What I think your friend has is a corneal condition called CORNEAL ARCUS. It is a relatively common condition usually found in ... It involves all layers of the cornea except for the corneal epithelium. The deposition is most prominent in Descemet membrane ... is actually a ring of hazy/white deposits on the edge of his cornea and accumulates 360 degrees of the corneal periphery. This ...
... ultrastructure with light transmission has been made in an attempt to resolve recent contradictory explanations of corneal ... A theoretical and experimental analysis of the relationship of the corneal stromal ... Histograms of the collagen fibril diameter in normal rabbit corneal stroma revealed the range to be 12.5-32.5 nm and the mean ... The spatial distribution of collagen fibrils in electronmicrographs of rabbit corneal stroma has been analysed in terms of a ...
This technique is sufficient to restore sight in the absence of deep corneal stroma damage. Further, the combination of ... Holoclar® and corneal transplants can restore a normal cornea for, previously incurable, deep corneal burns. And, as only a ...
The Artemis maps the corneal epithelium and stroma layers, which optical scanners cannot. Artemis also provides an Integrated ... They cannot map individual corneal layers, the epithelium and the stroma, which contain important diagnostic information. ... The Artemis maps corneal thickness more accurately than optical scanners like the Orbscan. Failure to detect keratoconus (a ... Because it uses ultrasound instead of light, the Artemis sees and maps the corneal layers. 4-Even after optical and pachymetry ...
... which normally pumps fluid out from corneal stroma *Leads to chronic edema of stroma and epithelium, subepithelial bullae, pain ... Immunologic rejection of corneal endothelium *Fuchs dystrophy *Implantation of prosthetic intraocular lens ... Increased corneal thickness with loss of normal artifactual clefts between collagen lamellae ...
The layer of corneal tissue ablated in LASIK occurs in the stroma, a sublayer of the cornea. ... The doctor then applies the excimer laser, an ultraviolet laser used in eye surgery, to remove corneal tissue by ablation. ...
Material Properties of Porcine Corneal Stroma in Unconfined Compression NEMB2013. Tensile Properties of Polylactic Acid (PLA) ...
  • An abnormality of the stroma of cornea, also known as the substantia propria of cornea. (mcw.edu)
  • When the cornea does not have the correct shape and power for clear vision, a doctor of optometry may recommend one of several corneal modification techniques to correct the issue. (aoa.org)
  • All corneal modification procedures alter the curvature of the cornea so that incoming light is refracted at an angle that allows it to focus precisely on the retina. (aoa.org)
  • The ring of blue around his brown iris] is actually a ring of hazy/white deposits on the edge of his cornea and accumulates 360 degrees of the corneal periphery. (answerbag.com)
  • It involves all layers of the cornea except for the corneal epithelium. (answerbag.com)
  • Further, the combination of Holoclar ® and corneal transplants can restore a normal cornea for, previously incurable, deep corneal burns. (eurostemcell.org)
  • Failure to detect keratoconus (a tendency for the cornea to be conically shaped rather than spherical) because theepithelium (the outer corneal layer) compensates for and masks it in optical scans isanother principal cause of ectasia. (indmedica.com)
  • This occurs in the corneal epithelium (outermost layer of the cornea) and in the corneal stroma (middle layer of the corneal tissue). (glaucoma.org)
  • Light microscopy was used in the earliest studies of the cornea and lead to the first description of the lamellar structure of the stroma. (lancs.ac.uk)
  • Immunogold labelling has been used to map the distribution of several collagen types within the corneal and scleral stroma at the ultrastructural level and provided critical evidence for the role of type V collagen in the regulation of fibril diameter within the cornea. (lancs.ac.uk)
  • Currently, the only way to cure blindness caused by corneal endothelial dysfunction is via corneal transplantation of a cadaver donor cornea with healthy corneal endothelium. (medsci.org)
  • Human corneal endothelial cells (HCECs) are embryologically derived from cranial neural crest progenitor cells (reviewed in [ 1 ]) and form a single monolayer of hexagonal cells lining the posterior cornea [ 2 ]. (medsci.org)
  • As a result, bullous keratopathy due to either an insufficient cell density caused by HCEC dysfunction or a retro-corneal membrane elicited by endothelial mesenchymal transition (EMT) may occur resulting in a cloudy cornea and potential corneal blindness [ 12 , 13 ]. (medsci.org)
  • In a corneal collagen crosslinking procedure, the clinician saturates the cornea with topical riboflavin applied to the surface and then exposes the tissue to a narrow spectrum of UV-A. The procedure creates a biochemical reaction when the riboflavin is photo-activated, resulting in increased covalent bonding between collagen fibers. (reviewofoptometry.com)
  • A 3D-printed artificial cornea made of decellularised corneal stroma and stem cells may eventually replace the use of donated corneas in eye surgery. (medicaldevice-network.com)
  • Because the 3D-printed cornea is composed of materials deriving from corneal tissue it is biocompatible, with 3D cell printing technology recapitulating the corneal microenvironment so that its transparency is similar to the human cornea. (medicaldevice-network.com)
  • A 3D-printed artificial cornea derived from real corneal tissue could help to bypass both the difficulties of finding a donor match and the complications associated with synthetic corneas for patients with cataracts and other ocular complications. (medicaldevice-network.com)
  • Pohang University of Science & Technology professor Jinah Jang said: "The suggested strategy can achieve the criteria for both transparency and safety of engineered cornea stroma. (medicaldevice-network.com)
  • Human Keratocytes (HK), aka Corneal Fibroblasts, provided by Innoprot are isolated from human healthy cornea. (innoprot.com)
  • Corneal foreign body is foreign material on or in the cornea, usually metal, glass, or organic material. (medscape.com)
  • The Artemis maps the corneal epithelium and stroma layers, which optical scanners cannot. (indmedica.com)
  • The Descemet membrane, the endothelium, and the deep stroma are left intact. (crstoday.com)
  • substances which damage the superficial epithelium may cause slight irritation, whereas further penetration to the corneal stroma or endothelium may induce mild or severe irritation, respectively. (europa.eu)
  • High quality visualization of corneal endothelium. (konan.com)
  • Exclusive software for corneal endothelium cell analysis with Auto-trace function is integrated. (konan.com)
  • Diseases surgical technique developed since the start of the involving the corneal endothelium can be controlled twentieth century for the realization of corneal with endothelial or penetrating keratoplasties, and transplantation (CT). (bvsalud.org)
  • CT is the most common type those diseases that involve both the endothelium and of tissue transplantation made around the world, the corneal stroma generally require PK when there is substitution of all corneal layers (the (REINHART, 2011). (bvsalud.org)
  • Extracellular fibrillogranular material was present in the corneal stroma, Descemet's membrane, and scleral stroma. (elsevier.com)
  • The transmission electron microscope was responsible for first revealing the regular diameter and high degree of order of the collagen fibrils present in the corneal stroma and contrasting this with the irregular diameter of fibrils present in sclera. (lancs.ac.uk)
  • To analyze the morphology of corneal epithelial cells and keratocytes by in vivo confocal microscopy (IVCM) in patients with herpes simplex keratitis (HSK) as associated with corneal innervation. (harvard.edu)
  • Changes in superficial epithelial cell density and morphology correlated strongly with total nerve length, number, and corneal sensation. (harvard.edu)
  • Three agents-prednisolone acetate (PA), triamcinolone acetonide (TA), and lipid-based artificial tears (LBAT)-were tested in cadaveric porcine eyes imaged with hand-held spectral-domain OCT (SD-OCT). Anterior segment imaging was performed in triplicate with each agent at three sites: corneal epithelial surface, corneal wound interface, and anterior chamber. (arvojournals.org)
  • 0.5 million stromal and epithelial cells will be incorporated in 0.05ml of commercially available fibrin glue and pasted over the corneal lesion after epithelial debridement. (clinicaltrials.gov)
  • Integrin: Basement membrane adhesion by corneal epithelial and endothelial cells. (harvard.edu)
  • Prominent features of a dendritic ulcer include a linear branching pattern within the corneal epithelium with terminal bulbs, swollen epithelial borders that contain live viruses, and central ulceration through the basement membrane. (medscape.com)
  • The earliest signs of neurotrophic keratopathy include an irregular corneal surface and punctate epithelial erosions. (medscape.com)
  • A small round opacity without epithelial defect was observed in the stroma of the previous corneal incision wound ( Fig. 1A , arrow), but wound infection was not suspected initially because there was no epithelial defect. (ekjo.org)
  • Interestingly, the structure of collagen fibrils in fish scale is very similar to that of human corneal stroma," says Ikoma. (titech.ac.jp)
  • Collagen fibril diameter in the human corneal stroma. (mpg.de)
  • Quantitative characterisation of the structural anisotropy in the human corneal stroma. (mpg.de)
  • [ 4 ] Fish eye disease is characterized by partial reduction of LCAT and only manifests as progressive corneal opacification. (medscape.com)
  • Lamellar keratoplasty is often preferred over penetrating keratoplasty because the former is associated with a decreased risk of graft rejection, irregular astigmatism, and corneal opacification. (crstoday.com)
  • The spatial distribution of collagen fibrils in electronmicrographs of rabbit corneal stroma has been analysed in terms of a radial distribution function. (nih.gov)
  • Specialised freezing-etching techniques have revealed the surface features of the collagen fibrils in corneal stroma, indicating clearly the presence of crossbridge structures between fibrils. (lancs.ac.uk)
  • Regulating the shear stress to control the pattern of the collagen fibrils manufactured the necessary corneal lattice pattern, demonstrating that corneal stroma-derived decellularised extracellular matrix bioink was biocompatible and could be transplanted into a human eye. (medicaldevice-network.com)
  • We postulate that these bands form spring-like links between zones of collagen lamellae, and their visibility is enhanced in pathologies where corneal shape is under stress. (archives-ouvertes.fr)
  • Scanning electron microscopy has proved useful in determining the 3D organisation of lamellae within both corneal and scleral stroma. (lancs.ac.uk)
  • 1. A theoretical and experimental analysis of the relationship of the corneal stromal ultrastructure with light transmission has been made in an attempt to resolve recent contradictory explanations of corneal transparency.2. (nih.gov)
  • The most sensitive way of detecting TMD progression is to identify a reduction in peripheral corneal thickness, preferably measured from the anterior stromal surface, with anterior segment OCT. Observation is essential because progression is common and varies in speed. (crstoday.com)
  • Most importantly we isolated a population of corneal stromal multipotent stem cells that have the ability to produce corneal epithelium, and are investigating their role in vivo corneal regeneration. (nottingham.ac.uk)
  • 0.1ml of stromal cells in a concentration of 5x10^3 cells/uL diluted in the thrombin component of fibrin glue (TISEEL, Baxter) will be applied to the debrided corneal stroma. (clinicaltrials.gov)
  • In the event of corneal injury or trauma, however, the keratocytes differentiate into active, synthesizing cells and rapidly replace damaged stromal matrix. (innoprot.com)
  • When a dendrite develops close to the limbus, its anterior stroma gets infiltrated by leukocytes from the limbal blood vessels, resulting in a dendritic lesion overlying an anterior stromal infiltrate. (medscape.com)
  • In patients with familial LCAT deficiency, symptoms are related to anemia, corneal opacities, renal insufficiency, and atherosclerosis (rarely). (medscape.com)
  • Corneal opacities may be severe enough to require corneal transplantation for the restoration of vision. (medscape.com)
  • In patients with fish eye disease, symptoms typically include corneal opacities and atherosclerosis (about 30% of cases). (medscape.com)
  • In cross-sectional views of normal and non-keratoconic corneas, these dark bands depart from anchor points at Descemet's membrane in the posterior stroma obliquely in a V-shape, whereas in keratoconus these bands depart vertically from posterior toward anterior stroma. (archives-ouvertes.fr)
  • The average anterior and posterior corneal power is 48.6 diopter (D) and -6.8 D, respectively. (medscape.com)
  • From placido disc corneal curvature topography to anterior and posterior corneal elevation, curvature and corneal thickness maps, optometrists are better positioned to identify corneal abnormalities than ever before. (reviewofoptometry.com)
  • Figure 4-4 A break in Descemet membrane in keratoconus shows anterior curling of Descemet membrane toward the corneal stroma (arrow) . (aao.org)
  • This paper reviews our existing understanding of the distribution and organisation of collagen types within the corneal and scleral stroma from a microscopical perspective. (lancs.ac.uk)
  • Fungal keratitis can cause serious damage to visual function of corneal infective disease, which is more difficult to treat.In recent years, injecting antifungal drugs to the corneal stroma not only enrich the treatment of the disease, but also achieve good clinical effects.Correctly selecting drug kinds and drug concentration can improve the cure rate, and reduce adverse reactions after treatment, but the related research is rare. (cjeo-journal.org)
  • This study was to observe the clinical effects of corneal stroma fluconazole injection with different concentration for the treatment of fungal keratitis. (cjeo-journal.org)
  • for moderate and heavy fungal keratitis patients, 0.2% fluconazole injection in corneal stroma can be performed after failure of 0.1% fluconazole treatment. (cjeo-journal.org)
  • Both of them showed development of keratitis during the management with corticosteroids, delayed onset, slow response to antibiotics, and relatively less affected corneal epithelium. (ekjo.org)
  • Micelli Ferrari T, Leozappa M, Lorusso M, Epifani E, Micelli Ferrari L. Escherichia coli keratitis treated with ultraviolet A/riboflavin corneal cross-linking: a case report. (medscape.com)
  • Inaccuracies in the measurement of corneal thickness leading to excessive LASIK flap thickness are a principal cause of ectasia. (indmedica.com)
  • While the incidence of post-LASIK ectasia is low, with reported rates from 0.04% to 0.2%, clinicians are meticulous about screening patients' corneal maps. (reviewofoptometry.com)
  • If the corneal stability achieved by CXL is permanent, could it be a cure for post-LASIK ectasia? (reviewofoptometry.com)
  • Zhu Q, Zhu Y, Tighe S, Liu Y, Hu M. Engineering of Human Corneal Endothelial Cells In Vitro . (medsci.org)
  • Human corneal endothelial cells are responsible for controlling corneal transparency, however they are notorious for their limited proliferative capability. (medsci.org)
  • Due to severe shortage of donor corneas worldwide, it has become paramount to develop human corneal endothelial grafts in vitro that can subsequently be transplanted in humans. (medsci.org)
  • Recently, we have reported effective expansion of human corneal endothelial cells by reprogramming the cells into progenitor status through use of p120-Kaiso siRNA knockdown. (medsci.org)
  • In this review, we present current advances in reprogramming corneal endothelial cells in vitro , detail the methods to successful engineer human corneal endothelial grafts, and discuss their future clinical applications to cure corneal blindness. (medsci.org)
  • Sudanophilic lipid deposits in Descemet membrane, Bowman zone and in a wedge-shaped portion of the peripheral corneal stroma. (answerbag.com)
  • A variety of refractive surgery techniques, which reshape the corneal stroma using laser energy, have been marketed as simple and safe alternatives to glasses or contact lenses. (aafp.org)
  • Can corneal collagen crosslinking expand the refractive surgery market? (reviewofoptometry.com)
  • In recent years, corneal topography devices have been used with greater frequency during refractive surgery work-ups. (reviewofoptometry.com)
  • The eyes with advanced disease demonstrated resolution of corneal clouding as early as 1 week post-injection, followed by sustained corneal transparency until the experimental endpoint of 25 weeks. (duke.edu)
  • The Artemis maps corneal thickness more accurately than optical scanners like the Orbscan. (indmedica.com)
  • Currently, no treatment exists to address MPS I corneal clouding other than corneal transplantation, which is complicated by a high risk for rejection. (duke.edu)
  • Corneal transplantation. (bvsalud.org)
  • The incisional surgical procedure used to correct corneal astigmatism. (aoa.org)
  • These 2 concepts can characterize the overall shape and the macro-irregularities of the corneal surface (eg, corneal astigmatism). (medscape.com)
  • Imaging with the Pentacam (Oculus Optikgeräte) showed 7.30 D of irregular corneal astigmatism and a maximum keratometry value of 52.60 D OD (Figure 1). (crstoday.com)
  • Two years after cataract surgery and the placement of an IOL in the bag, imaging with the Pentacam showed 7.30 D of irregular corneal astigmatism and a maximum keratometry value of 52.60 D OD. (crstoday.com)
  • Histograms of the collagen fibril diameter in normal rabbit corneal stroma revealed the range to be 12.5-32.5 nm and the mean value to be approximately 20 +/- 1.5 nm. (nih.gov)
  • Corneal swelling did not change the collagen fibril diameter significantly.5. (nih.gov)
  • This finding lead directly to the formulation of a theory of corneal transparency based on the uniformity of fibril diameter and packing. (lancs.ac.uk)
  • Our studies demonstrated ultrastructural elements of the extracellular matrix of the corneal stroma that are not seen using conventional electron microscopic techniques. (asme.org)
  • Methods for Investigating Corneal Cell Interactions and Extracellular Vesicles In Vitro. (harvard.edu)
  • Most cases are clinically recognizable in infancy with the loss of corneal clarity due to edema or scar. (medscape.com)
  • Corneal findings vary from minimal corneal edema to dense corneal leukoma. (medscape.com)
  • In some cases, corneal edema may regress with leaving residual scar behind. (medscape.com)
  • Glaucoma is always unilateral, usually exists at birth or shortly after, and presents as buphthalmos with or without corneal edema. (medscape.com)
  • Amnion has been extensively used for the regeneration of many tissues including the ocular surface where it has become a standard treatment for corneal defects. (nottingham.ac.uk)
  • The Bovine Corneal Opacity and Permeability Test (BCOP) utilises opacitometric and spectroscopic methods to quantitatively assess changes to bovine corneas, to determine ocular corrosivity and severe irritancy in vitro. (europa.eu)
  • Corneal foreign bodies generally fall under the category of minor ocular trauma. (medscape.com)
  • This is a investigative initiated, comparative pilot clinical trial to ascertain the safety of application of ex-vivo cultivated limbal stem cells in human eyes for treating different superficial corneal pathologies. (clinicaltrials.gov)
  • In this prospective interventional study patients with superficial corneal pathologies like scars, ulcers and burns will undergo a surgical procedure. (clinicaltrials.gov)
  • Superficial corneal foreign bodies are much more common than deeply embedded corneal foreign bodies. (medscape.com)
  • With 39 million corneal blind worldwide, developing affordable technologies as replacement tissue for corneal regeneration is a leading healthcare and therefore scientific priority. (nottingham.ac.uk)
  • Corneal opacity acts as an indicator of protein denaturation, swelling, vacuolation and tissue damage, whereas corneal fluorescein retention/leakage provides a measure of permeability. (europa.eu)
  • This concept is a simplification ignoring the fact that the initial refracting surface is the air-tear interface, and it does not account for the oblique incidence of incoming light in the corneal periphery. (medscape.com)
  • TMD is an infrequent, idiopathic, usually bilateral (56%-86%), 1 asymmetric, and often progressive disease that causes thinning, neovascularization, and lipid infiltration at the corneal periphery. (crstoday.com)
  • Through this dual function, HCECs play an important role in controlling corneal transparency by exerting pump function mediated via Na-K-ATPase [ 4 - 6 ], and barrier function facilitated through peri-junctional actomyosin ring (PAMR) and ZO-1 [ 3 , 7 - 9 ]. (medsci.org)
  • Academic Ophthalmology discovered mesenchymal stem cells residing in the corneal stoma, therefore redefining the conventional keratocyte. (nottingham.ac.uk)
  • Human Keratocytes, or corneal fibroblasts, are fibroblasts residing in the corneal stroma. (innoprot.com)
  • Damage to limbal stem cells and the corneal surface can lead to visual impairment and blindness/debilitation. (nottingham.ac.uk)
  • Smoothness of the surface is optically very important, and any micro-irregularities of the corneal surface can significantly degrade the image. (medscape.com)
  • To simplify it in clinical practice or in keratometry, a substitution with one refractive surface with the resulting corneal power of 42-44 keratometric D often is used. (medscape.com)
  • The visually significant area of the corneal surface is approximately the area with the same diameter as the pupil size. (medscape.com)
  • Figure 1 shows a large irregularity in the anterior corneal surface. (crstoday.com)
  • PA was applied to the corneal surface, and SD-OCT imaging was performed of the corneal surface and wound interface immediately after cataract surgery. (arvojournals.org)
  • The integrity of the corneal surface epithelium is essential for maintaining clarity of vision. (nottingham.ac.uk)
  • We used the technique of quick-freeze/deep-etch to examine the ultrastructure of the corneal stroma and then utilized morphometric studies to compute the specific hydraulic conductivity of the corneal stroma. (asme.org)
  • McKay TB , Kivanany PB, Nicholas SE, Nag OK, Elliott MH, Petroll WM, Karamichos D. Quercetin Decreases Corneal Haze In Vivo and Influences Gene Expression of TGF-Beta Mediators In Vitro. (harvard.edu)
  • Pre-clinical work in murine models have already demonstrated efficacy of this technique in curing murine corneal pathologies. (clinicaltrials.gov)
  • So the investigation of fish scale will be useful for the reconstruction of corneal stroma. (titech.ac.jp)
  • Because it uses ultrasound instead of light, the Artemis sees and maps the corneal layers. (indmedica.com)
  • Because it provides increased safety, an Artemis ultrasound scan will become the standard of care for LASIK and for other corneal refractive procedures. (indmedica.com)
  • Histological studies showed no significant corneal damage due to ultrasound application. (arvojournals.org)
  • Large paracentral herpes simplex virus dendritic corneal ulcer. (medscape.com)
  • [ 1 ] This article will review the relevant principles of corneal optics and discuss the major corneal imaging approaches, including topography, tomography, and optical coherence tomography. (medscape.com)
  • In addition to well-recognized contraindications (e.g., unstable refraction, pregnancy and lactation, chronic eye disease, systemic illness, corneal abnormalities), there are other conditions that warrant caution (e.g., excessively dry eyes, contact lens intolerance, chronic pain syndromes). (aafp.org)
  • Collectively, the results suggest that intrastromal AAV8G9-IDUA therapy prevents and reverses visual impairment associated with MPS I corneal clouding. (duke.edu)
  • Our study offers a clinical potential for a minimally invasive macromolecular treatment of corneal diseases. (arvojournals.org)
  • With the development of new surgical techniques, instrumentation and pharmacological advances, corneal transplant procedures can undergo changes directly in the clinical profile of patients with the indication for penetrating keratoplasty technique. (bvsalud.org)
  • Nine months before the development of scleritis, he had received an uneventful phacoemulsification and intraocular lens insertion through a corneal incision. (ekjo.org)
  • A lamellar keratoplasty replaces only the Bowman layer and the anterior portion of the corneal stroma. (crstoday.com)
  • The lesions of corneal manifestations consist of minute, grayish dots throughout the corneal stroma. (medscape.com)
  • White blood cells also may be liberated, resulting in an anterior chamber reaction and/or corneal infiltration. (medscape.com)
  • Corneal imaging is essential for preoperative planning in refractive, cataract, and corneal surgery, and for the diagnosis and monitoring of specific corneal diseases. (medscape.com)
  • Decreased corneal sensitivity helps confirm the diagnosis. (medscape.com)
  • Xu Z, Yu X, Li Z, Wang L. The role of in vivo confocal microscopy in the diagnosis of hidden corneal foreign bodies. (medscape.com)
  • Mucopolysaccharidosis type I (MPS I) is an autosomal recessive lysosomal storage disease characterized by severe phenotypes, including corneal clouding. (duke.edu)
  • Investigation of an adeno-associated virus (AAV) IDUA gene addition strategy targeting the corneal stroma addresses this deficiency. (duke.edu)
  • Changes were correlated to corneal sensation, number of nerves, and total length of nerves. (harvard.edu)
  • However, corneal scarring or infection may occur. (medscape.com)
  • Dry eye symptoms are multifactorial, but some may be manifestations of corneal neuropathy. (aafp.org)
  • In the second procedure, the central corneal epithelium will be removed using a surgical sponge. (clinicaltrials.gov)