Corneal Stroma: The lamellated connective tissue constituting the thickest layer of the cornea between the Bowman and Descemet membranes.Cornea: 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)Keratitis: Inflammation of the cornea.Corneal Keratocytes: Fibroblasts which occur in the CORNEAL STROMA.Keratan Sulfate: 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.Epithelium, Corneal: Stratified squamous epithelium that covers the outer surface of the CORNEA. It is smooth and contains many free nerve endings.Corneal Opacity: Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.Corneal Diseases: Diseases of the cornea.Corneal Transplantation: Partial or total replacement of the CORNEA from one human or animal to another.Keratoconus: 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)Onchocerciasis, Ocular: 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.Descemet Membrane: 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.Corneal Dystrophies, Hereditary: 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.Anterior Eye Segment: The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.Corneal Edema: An excessive amount of fluid in the cornea due to damage of the epithelium or endothelium causing decreased visual acuity.Collagen: 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).Corneal Neovascularization: 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.Endothelium, Corneal: Single layer of large flattened cells covering the surface of the cornea.Hematoxylin: A dye obtained from the heartwood of logwood (Haematoxylon campechianum Linn., Leguminosae) used as a stain in microscopy and in the manufacture of ink.Lasers, Excimer: 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)Stromal Cells: 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.Fluorescent Antibody Technique, Indirect: 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)Keratoplasty, Penetrating: Partial or total replacement of all layers of a central portion of the cornea.Keratomileusis, Laser In Situ: 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.Photorefractive Keratectomy: 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.Fibrillar Collagens: A family of structurally related collagens that form the characteristic collagen fibril bundles seen in CONNECTIVE TISSUE.Rabbits: 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.Corneal Ulcer: 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.Proteoglycans: Glycoproteins which have a very high polysaccharide content.Refractive Surgical Procedures: 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.Eosine Yellowish-(YS): 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.Wound Healing: Restoration of integrity to traumatized tissue.Onchocerca volvulus: 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.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Eye Injuries: Damage or trauma inflicted to the eye by external means. The concept includes both surface injuries and intraocular injuries.Chondroitin Sulfate Proteoglycans: Proteoglycans consisting of proteins linked to one or more CHONDROITIN SULFATE-containing oligosaccharide chains.Keratitis, Herpetic: 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)Riboflavin: 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.Dermatan Sulfate: 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)Refractometry: 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).Microscopy, Confocal: 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.Neutrophil Infiltration: 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.Sclera: 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)Conjunctiva: The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball.Limbus Corneae: 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)Ophthalmic Solutions: Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.Extracellular Matrix: 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.Chick Embryo: 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.Glycosaminoglycans: 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.Chemokine CXCL1: A CXC chemokine with specificity for CXCR2 RECEPTORS. It has growth factor activities and is implicated as a oncogenic factor in several tumor types.Epithelium: One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.X-Ray Diffraction: 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)Eye Infections, Bacterial: 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.Mice, Inbred C57BLTransforming Growth Factor beta2: 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.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Cattle: 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.Ciliary Body: 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.Eye ProteinsMicroscopy, Electron: 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.Extracellular Matrix Proteins: 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, Cultured: 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.Eye: 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, Messenger: 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.Body Water: Fluids composed mainly of water found within the body.Immunoenzyme Techniques: 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.Epithelial Cells: 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, Fluorescence: 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.Spheroids, Cellular: 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)Fluorescent Antibody Technique: 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.Organ Culture Techniques: 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)Transforming Growth Factor beta: 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.Chemokines, CXC: Group of chemokines with paired cysteines separated by a different amino acid. CXC chemokines are chemoattractants for neutrophils but not monocytes.Basement Membrane: 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.Lens, Crystalline: 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.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Endothelium: A layer of epithelium that lines the heart, blood vessels (ENDOTHELIUM, VASCULAR), lymph vessels (ENDOTHELIUM, LYMPHATIC), and the serous cavities of the body.Reverse Transcriptase Polymerase Chain Reaction: 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 ...
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
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 ...
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 ...
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 ...
... 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.
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 ...
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 » ...
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
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 ...
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 ...
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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…
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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... Ibu Reni A.Defenisi • Mola hidatidosa ialah kehamilan abnormal, dengan ciri-ciri stroma vilus korialis langka vaskularisasi, dan ...
Simultaneous intratunnel cross-linking with intrastromal corneal ring segment implantation versus simultaneous epithelium-off cross-linking with intrastromal corneal ring segment implantation for keratoconus management Mohamed Hosny, Moustafa Nour, Sarah Azzam, Mohsen Salem, Esraa El-Mayah Department of Ophthalmology, Cairo University, Giza, Egypt Purpose: The purpose of this study is to compare the efficacy of intratunnel cross-linking combined with intrastromal corneal ring segment (ICRS) implantation versus combined epithelium-off (epi-off) cross-linking and ICRS implantation for the management of keratoconus.Methods: Our study included 20 eyes of 12 patients with moderate-to-severe keratoconus. Group A included 10 eyes that underwent simultaneous ICRS implantation with intratunnel cross-linking. Group B included 10 eyes that underwent simultaneous ICRS implantation with epi-off cross-linking. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest sphere and
This invention is an intrastromal corneal ring having comprising at least one outer layer of a physiologically compatible polymer having a low modulus of elasticity, which polymer may be hydratable and may be hydrophilic. The inner portion of the hybrid intrastromal corneal ring may be hollow or may contain one or more physiologically compatible polymers.
Corneal collagen cross-linking with riboflavin (vitamin B2) and UV-A light is a surgical treatment for corneal ectasia such as keratoconus, PMD, and post-LASIK ectasia. It is used in an attempt to make the cornea stronger. According to a 2015 Cochrane review, there is insufficient evidence to determine if it is useful in keratoconus. In 2016, the US Food and Drug Administration approved riboflavin ophthalmic solution crosslinking based on three 12-month clinical trials. A 2015 Cochrane review that looked at all high quality evidence on corneal collagen cross-linking found that it was insufficient to determine if it is useful in keratoconus. Among those with keratoconus who worsen CXL may be used. In this group the most common side effects are haziness of the cornea, punctate keratitis, corneal striae, corneal epithelium defect, and eye pain. In those who use it after post-LASIK ectasia, the most common side effects are haziness of the cornea, corneal epithelium defect, corneal striae, dry eye, ...
Both Kerarings and Intacs have been shown to be an effective method of improving vision when used in isolation for patients with keratoconus. In 2014 Torquetti et al. [17] published data showing that Kerarings could effectively improve UDVA and CDVA in patients with keratoconus. Fahd et al. [18] showed Intacs to be safe and effective when used to treat eyes with moderate to severe keratoconus. However, recent data has suggested that there is regression in visual, refractive and topographic measures 5 years after ISCRS implantation [19]. This regression is to be expected as although the ISCRS flatten the cornea, they do not prevent the progression of the disease itself. CXL has therefore been used in combination with ISCRS to address this and provide the maximal visual improvement for the patient [20-22]. Our data shows ISCRS (INTACS and Kerarings) combined with CXL treatment to be a safe and effective treatment for keratoconus. We found both INTACS and Kerarings combined with CXL to produce a ...
This is a non-randomized study. All eyes that qualify for the study will receive the cross-linking (CXL) procedure. Corneal collagen cross-linking is performed as a single treatment. Depending on the patients condition, the CXL procedure may be performed under sedation or anesthesia. Subjects are followed for 12 months after the procedure to evaluate the long term effects of corneal collagen cross-linking ...
William Trattler, MD, gives an overview of recently FDA-approved corneal collagen cross-linking. Dr. Trattler gives advice on how to implement this procedure into your practice and how to identify and monitor patients.
Kim, B.Ki.; Mun, S.Joung.; Lee, D.Gyu.; Kim, J.Ryun.; Kim, H.Seung.; Chung, Y.Taek., 2015: Full-Thickness Astigmatic Keratotomy Combined With Small-Incision Lenticule Extraction to Treat High-Level and Mixed Astigmatism
Under-flap stromal bed CXL for early post-LASIK ectasia: a novel treatment technique Avi Wallerstein,1,2 Eser Adiguzel,2 Mathieu Gauvin,1,2 Nima Mohammad-Shahi,1 Mark Cohen2,3 1Department of Ophthalmology, Faculty of Medicine, McGill University, 2LASIK MD, Montreal, 3Department of Surgery, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada Purpose: Collagen cross-linking (CXL) for post-laser-assisted in situ keratomileusis (LASIK) ectasia (PLE) is traditionally performed either epi-on or epi-off on the corneal surface. This study describes a novel technique in treating early PLE with under-flap CXL (ufCXL) to the stromal bed and reports on 6-month outcomes.Patients and methods: Case series of seven patients (eight eyes) with topography-diagnosed early PLE treated with ufCXL. Inclusion criteria were early, mild PLE defined as new-onset postoperative manifest refraction cylinder â ¤1.50 D, with new topographic inferior steepening consistent with ectasia,
Deep intracorneal haemorrhage is most often seen after intraocular surgery, after direct, blunt ocular trauma, and in a vascularised cornea. The contribution of systemic factors such as diabetes or hypertension is unclear.2 Acne rosacea is known to cause peripheral vascularisation especially involving the inferonasal and inferotemporal quadrant. These vessels are known to progress in the absence of acute symptoms.3 In our patient, the corneal blood staining was a result of direct bleeding into the corneal stroma from the deep stromal vessels. The deep stromal vascularisation appears to have developed insidiously as in similar cases reported subsequent to contact lens wear.2 3 Corneal blood staining either from persisting hyphaema or deep intracorneal haemorrhage represents deposition of haemoglobin and its breakdown products within the cornea.4 A histopathological analysis of blood stained corneas, most of which were associated with raised intraocular pressures, indicated a gradient of ...
Tablet, yet now it is fabricated in two new structures that are; Generic Viagra Soft Tab and Generic Viagra Oral Jelly.! Most medication adjustments require a reduction in the dose, rotahaler pump lengthening of the dosing interval, or both.. Herpetic stromal keratitis is treated initially with prednisolone drops every 2 hours accompanied by a prophylactic antiviral drug: either topical antiviral or an oral agent such as acyclovir or valacyclovir.! Some of your health problems could be a contraindication or your dose of Vardenafil Online will should be adjusted by your healthcare supplier.. Men tend to have their first outbreak between 55 and 65 years of age. Women are more likely to get it between the ages of 15 and 25 years.? Assim sendo, rotahaler foracort é provável que o paciente ao fazer o tratamento com o remédio venha a sentir as chamadas reações adversas que são as dores abdominais, náuseas e diarreia, embora o mais comum seja as incômodas dores de cabeça. Se o paciente é ...
Our practice is devoted to providing the highest standard of patient care. We have invested in this advanced technology to maintain that level of commitment. We use the IntraLase femtosecond laser to make the flap, thereby making LASIK an ALL-LASER procedure.. The IntraLase laser provides a less invasive, computer controlled approach to the important first step of the laser vision correction procedure. This step, traditionally performed with a surgical blade, has now been enhanced by the lasers micron level accuracy, making every procedure more predictable. This remarkable precision, provided by IntraLase technology, enables you to choose laser vision correction with confidence. By replacing the traditional approach with a silent, tiny beam of laser light, the IntraLase FS laser allows more patients to become candidates for laser vision correction due to this unique level of precision that was previously unavailable.. In seconds, with computer precision and high-speed delivery, the Intralase ...
TY - CONF. T1 - Proteome analysis of serum-cultured human corneal fibroblasts. AU - Karring, Henrik AU - Thøgersen, Ida B. AU - Klintworth, Gordon K. AU - Enghild, Jan J. AU - Møller-Pedersen, Torben. PY - 2004. Y1 - 2004. M3 - Poster. Y2 - 8 November 2004 through 12 November 2004. ER - ...
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This presentation by Dr. Roger Steinert reviews the use of femtosecond laser for the creation of incisions in corneal transplantation procedures.
Department of Pathology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854 ...
A flat cornea with a mechanical microkeratome may be more likely to create a buttonhole flap. A buttonhole is a flap that the steel blade breaks the surface in the center, creating a hole. It is not a catastrophic problem, but it is a problem you want to avoid. The more planar shape of the Lasik flap created with a femtosecond laser may be more appropriate, as indicated by your surgeon ...
On procedure day Garber was first seen by Hunkeler Eye Institutes LASIK coordinator Donna. Donna first checked in with McKensie assuring that she understood the procedure and everything that came after including postoperative appointments, what she may feel after surgery and when to expect to feel completely normal again. Measurements were taken of the eye for the custom LASIK procedure the day of surgery. Before the procedure McKensie was given a medication to help her relax and an eye drop to dilate the eyes. When it is time for the procedure the patient is taken to the LASIK suite where they lay down for the duration of the procedure.. Dr. McKnight uses the intralase method. intralase is different from traditional LASIK methods because it is the first blade free way to create a corneal flap. Traditional LASIK methods use an instrument called a microkeratome to create a corneal flap.. Using the intralase method tiny, ultra precise pulses of laser light are used to create the corneal flap so ...
Download pdf Article Swadique M, Vijisha T, Jubairiya F. Changes in the magnitude of Keratoconus after Corneal Collagen cross linking with ultraviolet Light and Riboflavin. National Journal of Medical and Allied Sciences 2015; 4(1):46-49. ...
FLIVC (Femtosecond Laser Intrastromal Vision Correction) is a laser eye surgery technology that is one of several possible alternatives to LASIK now under investigation. Lower-energy femtosecond lasers may improve upon the traditional excimer laser by reducing disruption of ocular structures, with intrastromal ablation obviating the need for the damaging epithelial incision and ablation currently employed in LASIK and PRK procedures.read more at IntraLASIK ...
Laser-scanning in vivo confocal microscopy (IVCM) of the cornea is becoming an increasingly popular tool to examine the living human cornea with cellular-level detail in both healthy and pathologic states. Here, we describe the use of the IVCM technique to examine the processes of tissue healing and regeneration in the living human eye after biomaterial implantation. The regenerative response can be assessed by performing longitudinal IVCM imaging of a laboratory-made, cell-free biomaterial, after direct implantation into a pathologic eye as a primary alternative to human donor tissue transplantation.. ...
Andy Morgenstern, OD, discusses a recent panel discussion he moderated regarding corneal collagen cross-linking (CXL). He highlights the importance of early identification of disease in order to preserve the vision of patients and to prevent the progression of keratoconus.
Purpose: Accidental or surgical-induced trauma (e.g., refractive surgery) to the corneal epithelium results in keratocyte death immediately below the wound. Subsequent recovery of keratocytes during healing often remains ...
Intacs for keratoconus Yaron S. Rabinowitz Purpose of review The use of Intacs as a therapeutic modality in contact lens intolerant patients with mild to moderate keratoconus is increasingly gaining acceptance
Susanna realized she had keratoconus, a condition in which the cornea becomes weak and irregularly shaped, when she found herself driving and suddenly not able to see the license plate of the car in front of her. She immediately made an appointment with Dr. Sandy T. Feldman and scheduled a corneal collagen cross-linking (CXL) procedure.. Susanna was extremely happy with Dr. Feldman, the Clearview staff and the results. Just two days after the procedure, she went from having 20/70 vision in her right eye to 20/25.. Learn more about how this procedure can improve your life. Contact us today!. ...
Abstract: Motility initiation in crawling cells requires transformation of a symmetric state into a polarized state. In contrast, motility arrest is associated with re-symmetrization of the internal configuration of a cell. Experiments on keratocytes suggest that polarization is triggered by the increased contractility of motor proteins but the conditions of re-symmetrization remain unknown. In this paper we show that if adhesion with the extra-cellular substrate is sufficiently low, the progressive intensification of motor-induced contraction may be responsible for both transitions: from static (symmetric) to motile (polarized) at a lower contractility threshold and from motile (polarized) back to static (symmetric) at a higher contractility threshold. Our model of lamellipodial cell motility is based on a 1D projection of the complex intra-cellular dynamics on the direction of locomotion. In the interest of analytical transparency we also neglect active protrusion and view adhesion as passive. ...
Treat your corneal erosion or keratoconus with intacs cornea implants placed by Dr. Wong in Austin, Round Rock, Cedar Park, Leander & Buda TX. 512-345-5030
Mature corneal endothelial cells are arranged in a single layer that is critical for maintaining hydration of the corneal stroma, via metabolic pumps that actively transport fluid out of the stroma and into the anterior chamber ...
(2005) Du et al. Stem cells (Dayton, Ohio). Keratocytes of the corneal stroma secrete a specialized extracellular matrix essential for vision. These quiescent cells exhibit limited capacity for self-renewal and after cell division become fib...
All keratocytes participate in sphere formation. A: Freshly isolated primary keratocytes were cultured in polyHEMA-coated dishes either in Advanced-DMEM (ADV, d
What is an indolent corneal ulcer?. An indolent corneal ulcer is a superficial break in the corneal surface that refuses to heal. The cornea (the clear surface of the front of the eye) is covered with epithelium similar to the skin that covers the rest of the body. An ulcer is a break in the epithelium that exposes the underlying tissue (corneal stroma). An ulcer is similar to a scrape or abrasion of the skin. Fibronectin is a similar substance to a scab that forms across a corneal ulcer immediately after wounding and it serves as a base for epithelial cells to migrate over and heal the wound. As the epithelial cells migrate across, the fibronectin is removed by a series of enzymes. If the fibronectin is removed prematurely by excessive enzyme production or fails to be removed due to a lack of enzymes the corneal ulcer fails to heal. One theory of why an indolent corneal ulcer fails to heal is there is either excessive enzyme production or diminished enzyme production It appears that ...
There are five layers of the cornea. The outer epithelium is smooth to absorb oxygen and nutrients from tears. It also blocks foreign matter from getting into the eye. Next is Bowmans layer, which is a transparent sheet of collagen that can form scar tissue if damaged. The stroma is primarily water and collagen and makes up about 90 percent of the cornea. It gives the cornea its form, elasticity, and strength. Descemets membrane is a tough layer of tissue that protects against injuries and infection. Finally, the endothelium is a thin layer inside the cornea that serves to defend against fluid buildup in the stroma and keep it transparent. In most cases of surgery or vision correction, an eye specialist will provide insight on the procedure by informing you about such layers ...
The disease is characterised by thinning and conuslike protrusion of the cornea.. The Definition of Keratoconus. Keratoconus is a congenital disease of the cornea (autosomal dominant or autosomal recessive) and it belongs to the large group of hereditary corneal dystrophies.. The disease is characterised by thinning and conuslike protrusion of the cornea. This is due to alterations that cause weakening of the corneal structure ...
Corneal Stroma, Embryogenesis, Epitopes, Keratan Sulfate, Aid, Associations, Biology, Collagen, Enzymes, Mucopolysaccharidoses, Nature, Proteoglycan, Roles, Sly Syndrome, Syndrome, Understanding
PURPOSE OF REVIEW:. Artificial corneas are being developed to meet a shortage of donor corneas and to address cases in which allografting is contraindicated. A range of artificial corneas has been developed. Here we review several newer designs and especially those inspired by naturally occurring biomaterials found with the human body and elsewhere.. RECENT FINDINGS:. Recent trends in the development of artificial corneas indicate a move towards the use of materials derived from native sources including decellularized corneal tissue and tissue substitutes synthesized by corneal cells in vitro when grown either on their own or in conjunction with novel protein-based scaffolds. Biologically inspired materials are also being considered for implantation on their own with the view to promoting endogenous corneal tissue.. SUMMARY:. More recent attempts at making artificial corneas have taken a more nature-based or nature-inspired approach. Several will in the near future be likely to be available ...
Goodfellow, Julia (1975). Structural studies of the corneal stroma (PhD thesis). Open University. Goodfellow profile at the ...
... 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". Invest. Ophthalmol. Vis. Sci. 53 (9): 5109-16. doi:10.1167/iovs.11- ... "Isolation and Characterization of Human Clonogenic Osteoblast Progenitors Immunoselected from Fetal Bone Marrow Stroma Using ...
Mar-Apr 1995). "Refractive index of the human corneal epithelium and stroma". J Refract Surg. 11 (2): 100-105. PMID 7634138. ...
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 ...
Hamrah P, Liu Y, Zhang Q, Dana MR (February 2003). "The corneal stroma is endowed with a significant number of resident ... "Novel characterization of MHC class II-negative population of resident corneal Langerhans cell-type dendritic cells". Invest. ...
... 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 ... stroma which lies between the epithelium and the endothelium. Keratitis means corneal inflammation. Acutely or at the early ...
"Acquisition of type IX collagen by the developing avian primary corneal stroma and vitreous". Dev. Biol. 128 (2): 396-405. doi: ...
There may be an increase in the number of mucopolysaccharides in the corneal stroma. The Bowman's layer of the cornea may be ... PMD lacks apical corneal scarring, Rizutti's phenomenon, Munson's sign, and the central corneal thickness is usually normal. ... The gold standard diagnostic test for PMD is corneal topography. However, it may not as specific as corneal pachymetry, because ... Corneal topography may show a "crab claw-like" appearance, a finding that is seen in both keratoconus and in pellucid marginal ...
Daxer A, Misof K, Grabner B, Ettl A, Fratzl P. "Collagen fibrils in the human corneal stroma: structure and aging." Invest ... Daxer A, Fratzl P. "Collagen fibril orientation in the human corneal stroma and its implication in keratoconus." Invest ... "Structural transformation of collagen fibrils in corneal stroma during drying. An x-ray scattering study." Biophys J. 1993 Apr; ... Facts About The Cornea and Corneal Disease National Eye Institute (NEI). *Keratoconus (Irregular Astigmatism), Patient Support ...
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 ... Advantages Less damage to corneal nerves, hence safer in dry eyes If cornea is abnormal for LASIK, epilasik may still be an ... 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. Roger Steinert ... 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 ...
The flap is then folded back, and the microkeratome removes a thin disc of corneal stroma below. The thickness and diameter of ... While still attached at one side, the corneal flap is folded back to reveal a sub layer of cornea. At this point, the ... After the power cut, the corneal flap is laid back over the eye where it reattaches. ALK is an effective technique for very ...
... slowly progressive thinning of the peripheral corneal stroma. The cause of Terrien marginal degeneration is unknown, its ...
Daxer A, Fratzl P (1997). "Collagen fibril orientation in the human corneal stroma and its implications in keratoconus". Invest ... The corneal transplant surgeon trephines a lenticule of corneal tissue and then grafts the donor cornea to the existing eye ... In the USA, corneal transplants (also known as corneal grafts) for keratoconus are usually performed under sedation as ... Complications of corneal transplants are mostly related to vascularization of the corneal tissue and rejection of the donor ...
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. ...
In the corneal stroma, keratocytes within the wounded area undergo apoptosis, leaving the stroma devoid of cells that must be ... For example, when corneal integrity is compromised, epithelial cells quickly cover the damaged area by proliferation and ... "Role of Thrombospondin-1 in Repair of Penetrating Corneal Wounds". Invest Ophthalmology. 54: 7. doi:10.1167/iovs.13-11710. ...
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 ...
"Arc-scanning very high-frequency digital ultrasound for 3D pachymetric mapping of the corneal epithelium and stroma in laser in ... "Arc-scanning very high-frequency digital ultrasound for 3D pachymetric mapping of the corneal epithelium and stroma in laser in ... Vanderbeek, Brian L; Silverman, Ronald H; Starr, Christopher E (2009). "Bilateral Salzmann-like nodular corneal degeneration ... "Central corneal thickness measured by the Orbscan II system, contact ultrasound pachymetry, and the Artemis 2 system". Journal ...
According to one study, ITGA11 expression is increased in the anterior stroma of corneal buttons excised from the eyes affected ...
The response may result in the destruction of the corneal stroma, resulting in loss of vision due to opacification of the ... Stromal keratitis manifests as a disc-shaped area of corneal edema. Longstanding corneal edema leads to permanent scarring and ... may occur in the underlying stroma of iris. Sensation loss occurs in lesional areas, producing generalised corneal anaesthesia ... Corneal involvement is rarely seen in primary infection. Recurrent herpes of the eye is caused by reactivation of the virus in ...
... and inserts two crescent or semi-circular shaped ring segments between the layers of the corneal stroma, one on each side of ... Corneal collagen cross-linking[edit]. Corneal collagen cross-linking may delay or eliminate the need for corneal ... Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced ... Intrastromal corneal ring segments[edit]. In corneal disorders where vision correction is not possible by using contact lenses ...
It results from cholesterol deposits in or hyalinosis of the corneal stroma, and may be associated with ocular defects or with ... Arcus senilis is an old age syndrome where there is a white, grey, or blue opaque ring in the corneal margin (peripheral ... Xanthelasma Zech Jr, LA; Hoeg, JM (2008). "Correlating corneal arcus with atherosclerosis in familial hypercholesterolemia". ... corneal opacity), or white ring in front of the periphery of the iris. It is present at birth but then fades; however, it is ...
For candidates to qualify for this treatment, they have their corneal stroma thickness checked to make sure that post operative ... in that it uses a single femtosecond laser referenced to the corneal surface to cleave a thin lenticule from the corneal stroma ... Liu R, Zhao J, Xu Y, Li M, Niu L, Liu H, Sun L, Chu R, Zhou X (2015). "Femtosecond Laser-Assisted Corneal Small Incision ... There are limited studies on corneal wound healing and inflammatory response after this treatment has been carried out. There ...
These infectious agents produce proteases and collagenases which break down the corneal stroma. Complete loss of the stroma can ... Refractory corneal ulcersEdit. Main article: Recurrent corneal erosion. Refractory corneal ulcers are superficial ulcers that ... 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 ...
To report the presence of the R124H mutation in two Spanish families with Avellino corneal dystrophy (ACD). METHODS: Two ... Corneal Dystrophies, Hereditary / diagnosis, genetics*. Corneal Stroma / pathology. DNA Mutational Analysis. Extracellular ... RESULTS: In Family 1, Patients I-1, II-1, and II-3 presented granular deposits in the anterior stroma. In Family 2, Patients I- ... PURPOSE: To report the presence of the R124H mutation in two Spanish families with Avellino corneal dystrophy (ACD). METHODS: ...
March-April 1995). "Refractive index of the human corneal epithelium and stroma". J Refract Surg. 11 (2): 100-105. PMID 7634138 ...
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 ...
Defects in the corneal stroma caused by trauma or diseases such as macular corneal dystrophy and keratoconus can be detrimental ... Bioactive self-assembled peptide nanofibers for corneal stroma regeneration. By G. Uzunalli, Z. Soran, T.S. Erkal, Y.S. Dagdas ... Home / KnowledgeBase Articles / Bioactive self-assembled peptide nanofibers for corneal stroma regeneration ... Human corneal keratocyte cells cultured on laminin-mimetic peptide nanofibers retained their characteristic morphology, and ...
Development of the corneal stroma, and the collagen-proteoglycan associations that help define its structure and function. ... Bin Kong, Shengli Mi, Electrospun Scaffolds for Corneal Tissue Engineering: A Review, Materials, 2016, 9, 8, 614. CrossRef ... Shikha Chawla, Sourabh Ghosh, Establishment of in vitro model of corneal scar pathophysiology, Journal of Cellular Physiology, ... Sunil K. Parapuram, William Hodge, The integrin needle in the stromal haystack: emerging role in corneal physiology and ...
Surface ablation of corneal stroma with few-cycle laser pulses at 800 nm L. Hoffart, P. Lassonde, F. Légaré, F. Vidal, N. ... Wavelength dependence of femtosecond laser ablation threshold of corneal stroma G. Olivié, D. Giguère, F. Vidal, T. Ozaki, J.-C ... D. W. Leonard and K.M. Meek, "Refractive indices of the collagen fibrils and extrafibrillar material of the corneal stroma," ... D. W. Leonard and K.M. Meek, "Refractive indices of the collagen fibrils and extrafibrillar material of the corneal stroma," ...
Exogenous TGFβ3 promotes mouse corneal stroma development Lingling Zhang; Lung-Kun Yeh; Yujin Zhang; Yuka Okada; Yen-Chiao Wang ... Exogenous TGFβ3 promotes mouse corneal stroma development You will receive an email whenever this article is corrected, updated ... Methods : Primary corneal stroma fibroblasts were treated with BMP4, TGFβ3 or PBS (control) and related gene expressions were ... TEM revealed that TGFβ3 promotes mouse corneal stroma maturation by increasing stromal cell density and cell activates (more ER ...
Collagen type I and type V are present in the same fibril in the avian corneal stroma.. D E Birk, J M Fitch, J P Babiarz, T F ... Collagen type I and type V are present in the same fibril in the avian corneal stroma. ...
Its primary structural and mechanical element is the corneal stroma, comprising over 90% of corneal thickness. The stroma ... Meek KM Boote C. The organization of collagen in the corneal stroma. Exp Eye Res . 2004; 78: 503-512. [CrossRef] [PubMed] ... A large body of research has been devoted to exploring the structure and biomechanics of the corneal stroma. 1,4-11 However, ... Development of the corneal stroma, and the collagen-proteoglycan associations that help define its structure and function. Dev ...
However, the role of this signaling molecule in the corneal stroma has been long overlooked. The purpose of this study was to ... Retinoic Acid Improves Keratocyte Phenotype in a 3D Model of the Corneal Stroma ... Retinoic Acid Improves Keratocyte Phenotype in a 3D Model of the Corneal Stroma ... Retinoic Acid Improves Keratocyte Phenotype in a 3D Model of the Corneal Stroma. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):1300 ...
The corneal stroma of the lumican-null mouse, on the other hand, is, at all times studied, less well-organized than the corneal ... In the corneal stroma, collagen fibrils are uniformly thin, regularly spaced, and aligned with high spatial order. This ... Corneal opacity in lumican-null mice: defects in collagen fibril structure and packing in the posterior stroma. Invest ... Corneal Opacity in Lumican-Null Mice: Defects in Collagen Fibril Structure and Packing in the Posterior Stroma ...
PDGF-BB was expressed in the corneal and scleral stroma, whereas TM was expressed in the scleral, but not the corneal, stroma. ... PDGF-BB was expressed in the corneal and scleral stroma, whereas TM was expressed in the scleral, but not the corneal, stroma. ... PDGF-BB was expressed in the corneal and scleral stroma, whereas TM was expressed in the scleral, but not the corneal, stroma. ... PDGF-BB was expressed in the corneal and scleral stroma, whereas TM was expressed in the scleral, but not the corneal, stroma. ...
Ectopic expression of TGF-α in corneal keratocytes caused hyperplasia in the corneal epithelium and stroma. ... of corneal stroma keratocytes lacked expression of GFP (arrows). Ud, upper lid; Ld, lower lid; Co, cornea; Epi, corneal ... of corneal stroma keratocytes lacked expression of GFP (arrows). Ud, upper lid; Ld, lower lid; Co, cornea; Epi, corneal ... of corneal stroma keratocytes lacked expression of GFP (arrows). Ud, upper lid; Ld, lower lid; Co, cornea; Epi, corneal ...
Baiocchi S, Mazzotta C, Cerretani D, Caporossi T, Caporossi A. Corneal crosslinking: riboflavin concentration in corneal stroma ... Araie M, Maurice D. The rate of diffusion of fluorophores through the corneal epithelium and stroma. Exp Eye Res. 1987 ; 44: 73 ... Hatami-Marbini H, Etebu E, Rahimi A. Swelling pressure and hydration behavior of porcine corneal stroma. Curr Eye Res. 2013; 38 ... From x-ray scattering experiments21 in corneal stroma, we know that primarily the collagen molecule is superficially cross- ...
... images of the human corneal stroma is presented. The corneal OCT data is first processed using a state-of-the-art despeckling ... Cell density distribution analysis was carried in 3D UHR-OCT images of the human corneal stroma, acquired in-vivo. The cell ... Automated detection and cell density assessment of keratocytes in the human corneal stroma from ultrahigh resolution optical ... Automated detection and cell density assessment of keratocytes in the human corneal stroma from ultrahigh resolution optical ...
... cells within the corneal stroma and epithelium. Corneal Ag+ cells express mainly CD68, CD172 and rarely MHC class II molecules ... Corneal Stroma Macrophages Take Up Soluble Antigen Following Intracameral and Subconjunctival Injections: An in vivo and in ... Corneal Stroma Macrophages Take Up Soluble Antigen Following Intracameral and Subconjunctival Injections: An in vivo and in ... P.G. McMenamin, J. Kezic, S. Camelo; Corneal Stroma Macrophages Take Up Soluble Antigen Following Intracameral and ...
Ultrasound-Enhanced Penetration of Topical Riboflavin Into the Corneal Stroma. Stimulation of Corneal Epithelial Migration by a ... Differential expression of alternatively spliced fibronectin in normal and wounded rat corneal stroma versus epithelium. ... Differential expression of alternatively spliced fibronectin in normal and wounded rat corneal stroma versus epithelium. ... Universal Corneal Epithelial-Like Cells Derived from Human Embryonic Stem Cells for Cellularization of a Corneal Scaffold ...
At 24 and 30 hours, the corneal stroma of the area of the regenerated epithelium was transparent in the WT mouse, while it ... At 24 and 30 hours, the corneal stroma of the area of the regenerated epithelium was transparent in the WT mouse, while it ... At 24 and 30 hours, the corneal stroma of the area of the regenerated epithelium was transparent in the WT mouse, while it ... At 24 and 30 hours, the corneal stroma of the area of the regenerated epithelium was transparent in the WT mouse, while it ...
Purpose: To investigate the effects of loss of nitric oxide synthase type II (NOS2) in the healing of an injured corneal stroma ... Methods: The effect of lacking NOS2 on corneal stroma wound healing following an incision injury was evaluated by using NOS2- ... Results: Healing of an incision injury in corneal stroma was delayed with less invasion of macrophages and reduction in ... Appearance of myofibroblasts in the injured corneal stroma was suppressed by lacking NOS2 in vivo, although the loss of NOS2 ...
The Kinetics of Chemically Induced Nonequilibrium Swelling of Articular Cartilage and Corneal Stroma S. R. Eisenberg and A. J. ... The Kinetics of Chemically Induced Nonequilibrium Swelling of Articular Cartilage and Corneal Stroma. ASME. J Biomech Eng. 1987 ... Return to: The Kinetics of Chemically Induced Nonequilibrium Swelling of Articular Cartilage and Corneal Stroma ... To Understand Myopic Alleviation by Conducting Finite Element Structural Analysis of a Cornea With an Intrastromal Corneal Ring ...
The primary objective of the current study was to evaluate the efficacy of acellular porcine corneal stroma (APCS) ... Corneal stroma substitutes. The APCS graft used in the current study was prepared by AiNear Corneal Engineering Corporation ( ... Lamellar keratoplasty treatment of fungal corneal ulcers with acellular porcine corneal stroma. Am J Transplant. 2015;15:1068- ... Zheng J, Huang X, Zhang Y, Wang Y, Qin Q, Lin L, Jin X, Lam C, Zhang J. Short-term results of acellular porcine corneal stroma ...
Our goal was to establish in vitro assay for studying human corneal stroma injuries and the role stroma-derived stem cells have ... Results: : Corneal stroma cells could grow in culture for more than 10 passages (n=6). The most important markers of MSCs (CD73 ... Corneal stroma MSC-like cells could suppress the proliferation of activated peripheral blood lymphocytes, migrated and closed ... Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Immunity, Wound Healing and Angiogenesis ...
Szentmáry, N., Nagy, Z. Z., Resch, M., Szende, B., & Süveges, I. (2005). Proliferation and apoptosis in the corneal stroma in ... Szentmáry, N, Nagy, ZZ, Resch, M, Szende, B & Süveges, I 2005, Proliferation and apoptosis in the corneal stroma in longterm ... Proliferation and apoptosis in the corneal stroma in longterm follow-up after photorefractive keratectomy. Pathology Research ... Proliferation and apoptosis in the corneal stroma in longterm follow-up after photorefractive keratectomy. In: Pathology ...
These corneal qualities have also allowed for high-resolution in vivo imaging of non-ocular tissue transplanted into the ... Confocal Imaging of Myeloid Cells in the Corneal Stroma of Live Mice Edited by. Jia Li ... How to cite: Chan, M. F. and Werb, Z. (2015). Confocal Imaging of Myeloid Cells in the Corneal Stroma of Live Mice. Bio- ... Chan, M. F. and Werb, Z. (2015). Confocal Imaging of Myeloid Cells in the Corneal Stroma of Live Mice. Bio-protocol 5(13): ...
Stem cells (Dayton, Ohio). Keratocytes of the corneal stroma secrete a specialized extracellular matrix essential for vision. ... Keratocytes of the corneal stroma secrete a specialized extracellular matrix essential for vision. These quiescent cells ... These results demonstrate the presence of a population of cells in the human corneal stroma expressing stem cell markers and ... These cells may be a resource for bioengineering of corneal stroma and for cell-based therapeutics. ...
  • The person experiences pain and a sudden severe clouding of vision, with the cornea taking on a translucent milky-white appearance known as a corneal hydrops. (wikipedia.org)
  • Many diseases such as corneal dystrophies, scars or ectatic disorders induce a distortion of its anatomy or physiology leading to loss of transparency and subsequent loss of vision. (biomedcentral.com)
  • Recurrent corneal erosion (RCE) can develop after mechanical injury, as a complication of chronic ocular surface disease, or as a result of inherited dystrophies of the epithelial basement membrane or stroma. (bmj.com)
  • Recently, the authors identified a gene, BIGH3 , in which different mutations cause a group of hereditary corneal dystrophies: lattice type I and IIIA (CDLI and CDLIIIA), granular Groenouw type I (CDGGI), Avellino (CDA), and Reis-Bücklers' (CDRB). (arvojournals.org)
  • Different staining patterns of amyloid and nonamyloid deposits observed with antibodies against the amino and carboxyl termini of KE suggest that two mechanisms of KE misfolding are implicated in the pathogenesis of 5q31-linked corneal dystrophies. (arvojournals.org)
  • Recent progress in the elucidation of the molecular nature of this heterogeneous group of conditions comprises the identification of a common genetic basis for Groenouw type I (CDGGI), Reis-Bücklers' (CDRB), lattice type I and IIIA (CDLI, CDLIIIA), and Avellino (CDA) corneal dystrophies. (arvojournals.org)
  • Corneal dystrophies usually manifest themselves during the first or second decade but sometimes later. (wikipedia.org)
  • Corneal dystrophies affect vision in widely differing ways. (wikipedia.org)
  • As clinical manifestations widely vary with the different entities, corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. (wikipedia.org)
  • Corneal hydrops might be caused by a tear in the recently discovered Dua's layer, a 15 micron thick layer between the corneal stroma and Descemet's membrane, Harminder Dua suggests that this finding will affect corneal surgery, including penetrating keratoplasty, and understanding of corneal dystrophies and pathologies, such as acute hydrops. (wikipedia.org)
  • Phototherapeutic keratectomy (PTK) using [Excimer laser] can restore and preserve useful visual function for a significant period of time in patients with anterior corneal dystrophies. (wikipedia.org)
  • 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. (osapublishing.org)
  • Development of therapeutic methods to enhance corneal regeneration is essential for treatment of these defects. (jascoinc.com)
  • METHODS: Orthotopic corneal allografts (C57BL/6 strain donor) and syngeneic grafts were performed in A/J mice. (biomedsearch.com)
  • Methods of corneal tattooing have at times been practiced often and at other times faded into obscurity, but overall, the methods have evolved throughout history. (wikipedia.org)
  • When these nanofibers were used for damaged rabbit corneas, laminin-mimetic peptide nanofibers increased keratocyte migration and supported stroma regeneration. (jascoinc.com)
  • The keratocyte phenotype and macrophage invasion in the stroma were evaluated after epithelial repair. (arvojournals.org)
  • Ki67 positivity was detected in the upper stroma on day 1, 4, 7, and 14, and keratocyte apoptosis on day 1, 4, 7, and 14 after PRK, but not at an earlier or later time. (elsevier.com)
  • The frequency and spatial distribution of keratocyte proliferation and apoptosis are likely to be important determinants of the corneal wound healing process, but the detailed regulatory mechanisms have not yet been characterized. (elsevier.com)
  • Considering existing scientific evidence, it seems that all types of MSCs have similar behavior in vivo [Table 1 ], and thus are able to achieve keratocyte differentiation and modulate the corneal stroma with immunomodulatory properties [ 17 ]. (biomedcentral.com)
  • As the keratis area takes on a whiter appearance, the area of corneal involvement resembles the sclera more closely. (uiowa.edu)
  • Patchy pigmentation was present in the corneal stroma and Descemet' membrane bilaterally. (hindawi.com)
  • Their further investigation of this pre-Descemet stroma confirms that it is stroma, and not a new corneal layer. (wikipedia.org)
  • In May 2013, Dr Harminder Dua discovered a sixth layer between the stroma and the descemet membrane which was named after him as the Dua's layer. (wikipedia.org)
  • Using a murine model of Aspergillus corneal infection, we also demonstrate that in the absence of RodA, A. fumigatus induces Dectin-1- and Dectin-2-dependent neutrophil recruitment to the corneal stroma and enhanced fungal killing. (jimmunol.org)
  • 12 Advances in the field of molecular genetics have allowed the generation of mice with targeted proteoglycan deficiencies, allowing investigations into the functional roles of specific corneal proteoglycans. (arvojournals.org)
  • To investigate the effects of loss of nitric oxide synthase type II (NOS2) in the healing of an injured corneal stroma in mice. (arvojournals.org)
  • Mice with a 1-Mb duplication developed corneal hyperplasia and thymic tumors, while two different 3- to 4-cM deficiencies were embryonically lethal in heterozygous mice. (genetics.org)
  • CXCR2 −/− and CCR1 −/− mice were immunized s.c. and injected into the corneal stroma with Ags from the parasitic helminth Onchocerca volvulus . (jimmunol.org)
  • These differences were not due to impaired KC and MIP-2 production in the corneal stroma of CXCR2 −/− mice, which was similar to BALB/c mice. (jimmunol.org)
  • Corneal Toxicity of Topical Tacrolimus Ointment in Mice with Corneal Epithelial Injury. (bioportfolio.com)
  • This positive clinical experience is matched by the results obtained in experimental models where orthotopic corneal transplants have been performed in immunocompetent mice and rats. (arvojournals.org)
  • 2007. Ultraviolet radiation-induced corneal degeneration in 129 mice. (nih.gov)
  • Ziegler cites several physicians who contributed to the development of corneal tattooing. (wikipedia.org)
  • Infectious causes include syphilis (commonest), followed by other bacterial infections (TB, Leprosy and Lyme disease) and parasitic infections (Acanthamoeba, Onchocerciasis or river blindness, Leishmaniasis, Trypanosoma cruzi or Chagas disease, Trypanosoma brucei or African sleeping sickness and microsporidia) The corneal scarring is the end result of the initial invasion of blood vessels into the corneal stroma as part of the inflammatory response. (wikipedia.org)
  • Three different groups of porcine corneas, five each, were compared regarding the riboflavin concentration in the anterior stroma. (arvojournals.org)
  • Using a murine model of A. fumigatus corneal infection, we showed that Δ rodA conidia induced significantly higher cytokine production, neutrophil infiltration, and more rapid fungal clearance from C57BL/6 corneas compared with the parent G10 strain, which was dependent on Dectin-1 and Dectin-2. (jimmunol.org)
  • This observation encouraged earlier research by the authors to assess the variation of corneal stiffness with age using tests on ex vivo donor corneas (Elsheikh et al . (royalsocietypublishing.org)
  • A number of studies have indicated keratoconic corneas show signs of increased activity by proteases, a class of enzymes that break some of the collagen cross-linkages in the stroma, with a simultaneous reduced expression of protease inhibitors. (wikipedia.org)
  • there was marked difference in eyes with young donor corneas which resulted in better corneal clarity and visual outcome. (wikipedia.org)
  • The technique routinely used for hyperopic LASIK uses a 110- to 160-µm thick corneal flap and a wide ablation with a peripheral blend zone. (medscape.com)
  • These masks were centered on the exposed corneal stroma between the laser beam and the eye, successively starting with the 4.5-mm mask, followed by the 4-mm mask, and, finally, the 3.5-mm mask, to allow the final ablation pattern to reveal a central graduated steepening comprised of 3 concentric rings. (medscape.com)