AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPsychiatry and PsychologyPhenomena and ProcessesAnthropology, Education, Sociology and Social PhenomenaHumanitiesInformation ScienceNamed GroupsHealth Care
Corneal TransplantationEye BanksDescemet Stripping Endothelial KeratoplastyTissue DonorsFetal Tissue TransplantationEpikeratophakiaEndothelium, CornealCorneaEndothelium, VascularBrain Tissue TransplantationTissue PreservationEndotheliumCorneal DiseasesGraft SurvivalLens, CrystallineGraft RejectionBlood DonorsTransplantation, HomologousTransplantation, HeterologousLiving DonorsCataractCorneal StromaDisclosurealpha-Crystallin A Chaingamma-CrystallinsCrystallinsConflict of InterestCorneal OpacityEndothelium, LymphaticDepth PerceptionCladoceraMass BehaviorOptical IllusionsKeratan SulfatePsychophysicsEndothelial Cellsbeta-CrystallinsCells, CulturedContrast SensitivityLightingPattern Recognition, Visual
CorneaTransplantationEpitheliumFunction of the corneal endotheliumRegenerationMonolayerPenetrating keratoplastyAcquired corneal opacityPolymorphous corneal dystrophyGraftEdemaAqueousStroma and endotheliumSpecular microscopyCollagen fibrilsDystrophyGraftsDescemet'sPosterior cornealTransplantsBlindnessMicroscopyCurvatureDescemetHealthy donor tissueOpacificationAstigmatismScarsAnteriorDiseasesTopographySevereCellsSmoothnessClinicallyBasement membraneDMEKFlapHydrationKeratitisOcularRefractiveSlitSurgicalScarOrganism
Cornea37
  • Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue (the graft). (wikipedia.org)
  • Corneal transplantation is performed when medicines, keratoconus conservative surgery and cross-linking can no longer heal the cornea. (wikipedia.org)
  • Cosmetic: To improve the appearance of patients with corneal scars that have given a whitish or opaque hue to the cornea. (wikipedia.org)
  • Replacing the affected cornea in part (lamellar or endothelial keratoplasty) or total (penetrating keratoplasty) with a healthy donor tissue is the current accepted standard of care. (arvojournals.org)
  • 1 If the number of corneal endothelial cells (CECs) falls below a certain threshold because of traumatic injury, disease, or normal aging processes, functionality of the CE is decreased, and the cornea swells and becomes milky, leading to eventual vision loss. (lww.com)
  • Anterior segment optical coherence tomography revealed the SF graft as a fully integrated component in the corneal tissue, displaying a similar corneal thickness and endothelial cell count when compared with its healthy contralateral cornea. (arvojournals.org)
  • In the early stages, the cornea can also have a "beaten metal" appearance with pigment dusting on the endothelium. (reviewofoptometry.com)
  • Over time, both the pump and barrier functions become compromised, causing the cornea to swell and lose transparency. (reviewofoptometry.com)
  • The representative cornea underwent a sutureless procedure using tissue adhesive for repositioning of the flap. (jamanetwork.com)
  • Gospodarowicz DGreenburg GAlvarado J Transplantation of cultured bovine corneal endothelial cells to rabbit cornea: clinical implications for human studies. (jamanetwork.com)
  • Transparency, avascularity, and immunologic privilege makes the cornea a very special tissue. (wikidoc.org)
  • The cornea is one of the most sensitive tissues of the body, it is densely innervated with sensory nerve fibres via the ophthalmic division of the trigeminal nerve by way of 70 - 80 long ciliary nerves and short ciliary nerves . (wikidoc.org)
  • This surgery could be a scraping of the surface of the cornea, or a corneal transplant. (houstoneyedoctorvital.com)
  • A corneal transplant is the replacement of the central portion of the cornea using donor corneal tissue (a donor graft or button) for the purpose of resorting corneal clarity, eliminating corneal swelling, improving corneal strength or thickness, or improving corneal shape. (houstoneyedoctorvital.com)
  • Anterior lamellar keratoplasty (abbreviated as: ALK, LK, or DALK) which replaces the front portion of the cornea (the stroma) without removing the innermost layer (the endothelium). (houstoneyedoctorvital.com)
  • Endothelial keratoplasty (abbreviated as: EK, DSEK, DMEK or DSAEK) which replaces only the innermost layers of the cornea and the endothelium. (houstoneyedoctorvital.com)
  • Corneal problems that lead to poor vision result in the cornea being cloudy (such that light is blocked), swollen (such that light is scattered), or misshapen (such that light is not focused). (houstoneyedoctorvital.com)
  • The goal of corneal surgery is usually to restore the clear, thin and focused characteristics of the cornea. (houstoneyedoctorvital.com)
  • This is achieved by manipulating the existing cornea or replacing it with a corneal transplant. (houstoneyedoctorvital.com)
  • Corneal endothelium is a monolayer of cells that acts as the major pump to deturgesce the cornea and ensures clarity. (medscape.com)
  • Slit lamp examination by specular reflection may show cornea guttata in the central part of the corneal endothelium. (medscape.com)
  • Experimental mice, i.e., wild-type, Col5a1 f/f and Kera-Cre/Col5a1 f/f ( Col5a1 ∆st/∆st , collagen V null in the corneal stroma) mice in a C57BL/6J genetic background, were subjected to a lamellar keratectomy, and treated with or without UMSC (10 4 cells/cornea) transplantation via an intrastromal injection or a fibrin plug. (molvis.org)
  • The cornea does so by having an organization consisting of three tissue layers: the epithelium, stroma, and endothelium. (molvis.org)
  • The cornea is approximately 500 microns thick (.5 millimeter) and consists of 5 layers of epithelium, Bowman's membrane, stroma, Descemet's membrane, and endothelium. (fisherswale.com)
  • The layer of the cornea between the stroma and endothelium. (fisherswale.com)
  • The word corneal opacification literally means loss of normal transparency of cornea. (mdwiki.org)
  • The term corneal opacity is used particularly for the loss of transparency of cornea due to scarring. (mdwiki.org)
  • Transparency of the cornea is dependent on the uniform diameter and the regular spacing and arrangement of the collagen fibrils within the stroma . (mdwiki.org)
  • The appearance of the cornea is similar to that in congenital glaucoma but without increased corneal diameter and elevated intraocular pressure. (mdwiki.org)
  • The corneal endothelium is a single layer of cells on the inner surface of the cornea . (iiab.me)
  • The corneal endothelium are specialized, flattened, mitochondria-rich cells that line the posterior surface of the cornea and face the anterior chamber of the eye . (iiab.me)
  • The corneal endothelium governs fluid and solute transport across the posterior surface of the cornea and maintains the cornea in the slightly dehydrated state that is required for optical transparency. (iiab.me)
  • The corneal endothelium is attached to the rest of the cornea through Descemet's membrane , which is an acellular layer composed mostly of collagen. (iiab.me)
  • The principal physiological function of the corneal endothelium is to allow leakage of solutes and nutrients from the aqueous humor to the more superficial layers of the cornea while at the same time pumping water in the opposite direction, from the stroma to the aqueous. (iiab.me)
  • Since the cornea is avascular, which renders it optimally transparent, the nutrition of the corneal epithelium, stromal keratocytes, and corneal endothelium must occur via diffusion of glucose and other solutes from the aqueous humor, across the corneal endothelium. (iiab.me)
  • Corneal endothelial cells are post-mitotic and divide rarely, if at all, in the post-natal human cornea. (iiab.me)
  • [7] The optical properties of the cornea reside in its transparency, which in turn depends on its fibrillar and cellular arrangement. (eyewiki.org)
Transplantation11
Epithelium5
  • Irregularity or edema of the corneal epithelium disrupts the smoothness of the air-tear film interface, the most significant component of the total refractive power of the eye, thereby reducing visual acuity. (wikidoc.org)
  • This stage is characterized by increasing visual and other problems, caused by incipient edema of the corneal stroma initially and later the epithelium. (medscape.com)
  • The non-regenerative layer of tissue between the epithelium and the stroma (5-10 microns thick - .005 to .01 millimeters). (fisherswale.com)
  • Not to be confused with the corneal epithelium . (iiab.me)
  • The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye, which acts as a protective barrier and is critical for clear and stable vision. (wjgnet.com)
Function of the corneal endothelium2
  • The most important function of the corneal endothelium (CE) is maintenance of corneal transparency by regulating water content of the corneal stroma. (lww.com)
  • This dual function of the corneal endothelium is described by the "pump-leak hypothesis. (iiab.me)
Regeneration5
  • Regenerative medicine has been an increasingly successful method to treat disorders of the heart, pancreas and cartilage, but regeneration of the corneal endothelium has yet to reach a comparable stage. (reviewofoptometry.com)
  • The production of collagen V by transplanted UMSCs may account for the regeneration of corneal transparency, as exemplified by better collagen fiber organization, as revealed with SHG signals. (molvis.org)
  • There is no medical treatment that can promote wound healing or regeneration of the corneal endothelium. (iiab.me)
  • She was awarded with a postdoc fellow from the Ministry of Science at the Technical University of Catalonia in Biomaterials for bone tissue regeneration and since 2010 has been professor at this university. (ibecbarcelona.eu)
  • Tissue and organ regeneration company LyGenesis has shown that it can regrow functioning ectopic organs in a patient s lymph nodes using cellular therapy. (regenerativemedicine.net)
Monolayer5
  • Given that nearly a half of all the transplantations performed in a year are for replacing only the dysfunctional endothelium, 2 the monolayer of cells that maintain corneal transparency, research has focussed on engineering this layer in the laboratory. (arvojournals.org)
  • The corneal endothelium is the posterior monolayer of cells that are responsible for maintaining overall transparency of the avascular corneal tissue via pump function. (ulster.ac.uk)
  • Histologic analysis showed that the SF artificial endothelial graft was attached and integrated on the surface of the corneal stroma without a significant inflammatory reaction, and rabbit CECs consisted in a monolayer that showed their characteristic markers ZO-1 and Na + /K + ATPase, suggesting proper intercellular junctions and cellular pump function. (arvojournals.org)
  • a simple squamous or low cuboidal monolayer of mitochondria-rich cells responsible for regulating fluid and solute transport between the aqueous and corneal stromal compartments. (wikidoc.org)
  • Wounding of the corneal endothelium, as from trauma or other insults, prompts healing of the endothelial monolayer by sliding and enlargement of adjacent endothelial cells, rather than mitosis. (iiab.me)
Penetrating keratoplasty2
  • Compared with penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK) presents several advantages that make it currently considered by many corneal surgeons as the first-choice surgical procedure in patients with keratoconus. (bmj.com)
  • PPMD patients with bilateral, corneal opacities that can affect vision, descemet's membrane endothelial keratoplasty or penetrating keratoplasty are the treatments of choice to improve vision and to avoid amblyopia. (mdwiki.org)
Acquired corneal opacity1
  • The purpose of this study is to examine the therapeutic efficacy of human umbilical cord mesenchymal stem/stromal cells (UMSCs) in treating congenital and acquired corneal opacity associated with the loss of collagen V. (molvis.org)
Polymorphous corneal dystrophy1
  • Posterior polymorphous corneal dystrophy is also a dominantly inherited bilateral disease, but can have an asymmetric presentation. (reviewofoptometry.com)
Graft3
  • The graft is taken from a recently deceased individual with no known diseases or other factors that may affect the chance of survival of the donated tissue or the health of the recipient. (wikipedia.org)
  • DIR-labelled CECs were detectable in vivo up to 1 month, and transplanted labelled donor graft could be visualized and were trackable in vivo. (bvsalud.org)
  • In a rabbit model of DMEK surgery, SF artificial endothelial graft restored the corneal transparency and thickness at 6 week of follow-up. (arvojournals.org)
Edema5
  • Corneal edema is infrequent, but can occur and may be rapidly progressive. (reviewofoptometry.com)
  • Tiny droplets of corneal epithelial edema (bedewing) are best seen using retroillumination. (medscape.com)
  • Alterations in the spacing of collagen fibrils in a variety of conditions including corneal edema, scars, and macular corneal dystrophy is clinically manifested as corneal opacity. (mdwiki.org)
  • Corneal edema can also occur as the result of compromised endothelial function due to intraocular inflammation or other causes. (iiab.me)
  • In addition, excessive corneal hydration can result in edema of the corneal epithelial layer, which creates irregularity at the optically critical tear film-air interface. (iiab.me)
Aqueous3
  • The corneal endothelium is bathed by aqueous humour , not by blood or lymph , and has a very different origin, function, and appearance from vascular endothelia . (wikidoc.org)
  • The endothelium serves three main purposes: it regulates the stroma's water content, it provides a barrier to the ingress of several constituents of the aqueous humor, and it actively transports glucose. (fisherswale.com)
  • The corneal endothelium then transports water from the stromal-facing surface to the aqueous-facing surface by an interrelated series of active and passive ion exchangers. (iiab.me)
Stroma and endothelium2
Specular microscopy1
  • Visual acuity, specular microscopy, corneal topography and optical coherence tomography findings were recorded. (bmj.com)
Collagen fibrils5
  • The corneal stroma consists of approximately 200 layers of type I collagen fibrils. (wikidoc.org)
  • The corneal stroma is composed of primarily collagen fibrils, small leucine-rich proteoglycans (SLRPs), as well as sparsely distributed cells called keratocytes. (molvis.org)
  • The lattice arrangement and spacing of the collagen fibrils that allows for transparency may be disrupted due to genetic mutations and injuries. (molvis.org)
  • Collagen V is a quantitatively minor component of predominantly type I collagen fibrils in most non-cartilaginous tissues. (molvis.org)
  • Excess hydration of the corneal stroma disrupts the normally uniform periodic spacing of Type I collagen fibrils, creating light scatter. (iiab.me)
Dystrophy6
  • The most common indication in this category is pseudophakic bullous keratopathy, followed by keratoconus, corneal degeneration, keratoglobus and dystrophy, as well as scarring due to keratitis and trauma. (wikipedia.org)
  • The corneal classification system names five dystrophies of Descemet's membrane (DM) and the endothelium-Fuchs' endothelial corneal dystrophy (FECD), posterior polymorphous dystrophy (PPD), congenital hereditary endothelial dystrophy 1 (CHED1), congenital hereditary endothelial dystrophy 2 (CHED2) and X-linked endothelial corneal dystrophy (XECD). (reviewofoptometry.com)
  • Fuchs', the most common corneal endothelial dystrophy, affects up to 2% of the US population. (reviewofoptometry.com)
  • X-linked endothelial corneal dystrophy is more common in males. (reviewofoptometry.com)
  • PPCD, also known as Schlichting dystrophy, is an autosomal dominant disorder of the corneal endothelium and Descemet's membrane. (mdwiki.org)
  • A rare disease called X-linked endothelial corneal dystrophy was described in 2006. (iiab.me)
Grafts3
  • All corneal grafts are screened for the presence of viruses such as HIV or hepatitis through antibody or nucleic acid testing, and there has never been a reported case of HIV transmission through corneal transplant surgery. (wikipedia.org)
  • The number of available corneal donor tissues is limited worldwide, hence, cultivation of human corneal endothelial cells (hCECs) in vitro has been attempted in order to produce tissue engineered corneal endothelial grafts. (ulster.ac.uk)
  • Human and rabbit artificial corneal endothelial grafts were developed through the culture of human and rabbit corneal endothelial cells (CECs) on SF films. (arvojournals.org)
Descemet's1
  • Researchers have attempted to recreate the current gold standard treatment of replacing the endothelial layer with accompanying Descemet's membrane or a small portion of stroma as support with tissue engineering strategies using various substrates of both biologically derived and synthetic origin. (ulster.ac.uk)
Posterior corneal2
  • The posterior corneal lamellae are first to become edematous. (medscape.com)
  • This honeycomb tiling scheme yields the greatest efficiency, in terms of total perimeter, of packing the posterior corneal surface with cells of a given area. (iiab.me)
Transplants2
  • Advances in the reproducibility and accessibility of surgical techniques are increasing the number of corneal transplants, thereby causing a global deficit of donor corneas and leaving 12.7 million patients with addressable visual impairment. (bvsalud.org)
  • These cells are non-regenerative in vivo and therefore, approximately 40% of corneal transplants undertaken worldwide are a result of damage or dysfunction of endothelial cells. (ulster.ac.uk)
Blindness3
  • This surgical procedure usually treats corneal blindness, with success rates of at least 41% as of 2021. (wikipedia.org)
  • Loss of corneal endothelial cells (CECs) bears disastrous consequences for the patient, including corneal clouding and blindness. (lww.com)
  • [2] The term "corneal blindness" is commonly used to describe blindness due to corneal opacity. (mdwiki.org)
Microscopy1
  • In vivo Heidelberg retinal tomograph (HRT II) confocal microscopy, second harmonic generated (SHG) confocal microscopy, histology, and immunofluorescence microscopy were used to assess the corneal transparency of the regenerated corneas. (molvis.org)
Curvature1
  • Kerectasia: In this condition, corneal curvature is increased at the site of opacity (bulge due to weak scar). (mdwiki.org)
Descemet2
  • The root cause of the condition is a slowly progressive formation of guttate lesions between the corneal endothelium and the Descemet membrane. (medscape.com)
  • All corneal layers may be compromised, but the Descemet membrane and endothelium are only affected in more advanced stages. (eyewiki.org)
Healthy donor tissue1
  • Indications include the following: Optical: To improve visual acuity by replacing the opaque or distorted host tissue by clear healthy donor tissue. (wikipedia.org)
Opacification1
  • Corneal opacification is the most common and classic eye finding of MPS. (eyewiki.org)
Astigmatism1
  • De Molfetta VBrambilla MDe Casa NArpa PRiva M Residual corneal astigmatism after perforating keratoplasty. (jamanetwork.com)
Scars3
Anterior1
  • Bowman's layer (also erroneously known as the anterior limiting membrane , when in fact it is not a membrane but a condensed layer of collagen): a tough layer that protects the corneal stroma, consisting of irregularly-arranged collagen fibers. (wikidoc.org)
Diseases2
  • The low endogenous regenerative capacity of the heart,added tothe prevalence of cardiovascular diseases, triggered the advent ofcardiac tissue engineering in the last decades. (ibecbarcelona.eu)
  • The study was also conducted in larger mammals with equally impressive results: Liver tissue grown in pigs lymph nodes could treat genetic liver diseases. (regenerativemedicine.net)
Topography1
  • Preoperative (A) and postoperative (B) corneal topography. (jamanetwork.com)
Severe1
  • In some cases, the infection can be severe enough to require a corneal transplant to restore good vision. (houstoneyedoctorvital.com)
Cells10
  • These results demonstrate the ability to tissue engineer a vascularized, full-thickness LV wall with an unparalleled level of microanatomical organization and multicellular composition, using decellularized ECM and human cardiomyocytes, endothelial cells, and other cardiac cell types. (bvsalud.org)
  • The corneal ECD decreased from 2494±382 cells/mm 2 to 1521±659 cells/mm 2 at 10 years. (bmj.com)
  • At left, the healthy donor endothelial cells form a regular hexagonal pattern. (reviewofoptometry.com)
  • Seminal studies in Japan have indicated that corneal endothelial cells may have some proliferative capacity when appropriately stimulated. (reviewofoptometry.com)
  • The aim of this study is to evaluate the feasibility, safety, and efficacy of cell therapy based on mesenchymal stromal cells derived from adipose tissue intramuscular administration to patients with type 2 diabetes mellitus with critical limb ischemia and without possibility of revascularization. (unav.edu)
  • A complication of LASIK wherein epithelial cells grow underneath the corneal flap. (fisherswale.com)
  • The normal corneal endothelium is a single layer of uniformly sized cells with a predominantly hexagonal shape. (iiab.me)
  • Lysosomes are present in all nucleated cells and consequently GAGs may potentially accumulate in every tissue. (eyewiki.org)
  • Therefore, we propose that damage to and subsequent release of mtDNA elicits a protective signalling response that enhances nDNA repair in cells and tissues, suggesting that mtDNA is a genotoxic stress sentinel. (regenerativemedicine.net)
  • Numerous cells working together toward one common goal are called tissue. (regenerativemedicine.net)
Smoothness1
  • How the scar will affect vision depends on the location, size, depth, transparency, and surface smoothness of the scar. (houstoneyedoctorvital.com)
Clinically1
Basement membrane2
  • a thin acellular layer that serves as the modified basement membrane of the corneal endothelium. (wikidoc.org)
  • In this stage, subepithelial connective tissue and pannus formation along the epithelial basement membrane are present. (medscape.com)
DMEK1
Flap2
  • D, Sutureless donor disc in place, flap repositioned, and glue (blue color) at the wound edges. (jamanetwork.com)
  • Pallikaris IGPapatzanaki MESiganos DSTsilimbaris MKPallikaris I A corneal flap technique for laser in situ keratomileusis: human studies. (jamanetwork.com)
Hydration1
  • The endothelium is one cell layer thick (5-10 microns or .005 -.01 millimeters) and provides hydration balance to maintain the cornea's transparency. (fisherswale.com)
Keratitis1
  • Corneal infections have names such as infectious keratitis, corneal ulcers, and corneal infiltrates. (houstoneyedoctorvital.com)
Ocular4
  • Which type of corneal transplant is appropriate for you depends on your specific ocular condition. (houstoneyedoctorvital.com)
  • Ocular form of mucous membrane pemphigoid may cause corneal opacity and loss of vision. (mdwiki.org)
  • The most common (classic or typical features) include corneal clouding, ocular hypertension and glaucoma, retinopathy and optic disc involvement (optic disc swelling or atrophy). (eyewiki.org)
  • [13] In a tertiary centre in Portugal, all 5 patients with MPS type VI presented corneal clouding and this was the first ocular manifestation. (eyewiki.org)
Refractive1
  • A "cold" laser used in refractive surgery to remove corneal tissue. (fisherswale.com)
Slit1
Surgical1
Scar3
  • How will a corneal scar affect my vision? (houstoneyedoctorvital.com)
  • For the vision in an eye with a corneal scar that is quiet, the vision should be corrected with glasses if possible. (houstoneyedoctorvital.com)
  • Corneoiridic scar: If iris tissue is incarcerated and incorporated within the scar tissue, as occurs in healing of a large sloughed corneal ulcer, it is called a corneoiridic scar. (mdwiki.org)
Organism2
  • An induced state of non-reactivity to grafted tissue from a donor organism that would ordinarily trigger a cell-mediated or humoral immune response. (lookformedical.com)
  • Corneal ulcers are usually treated with cultures to find the offending organism along with intensive regimens of antibiotic, antiviral, or antiparasitic drops to heal the infection. (houstoneyedoctorvital.com)