• The anterior ciliary arteries and veins penetrate the sclera nearly 3 to 4 mm away from the limbus. (wikidoc.org)
  • The sclera is almost avascular and its histological structure resembles that of the cornea. (wikidoc.org)
  • Fibrous Tunic is the outer layer of the optic wall composed of the opaque sclera and the transparent cornea. (histologyguide.com)
  • the junction of the opaque sclera and transparent cornea. (histologyguide.com)
  • Firstly, we know about Conjunctiva, it is a transparent mucous layer underlying the eyelids & cover the sclera up to limbus area. (optography.org)
  • 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. (nih.gov)
  • The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. (lookformedical.com)
  • Research suggests the more common nasal side occurrence is related to the light passing medially through the cornea, which focuses on the nasal limbus, whereas the nose may reduce the intensity of the UV light to the temporal limbus. (reviewofoptometry.com)
  • A procedure for removal of the crystalline lens in cataract surgery in which an anterior capsulectomy is performed by means of a needle inserted through a small incision at the temporal limbus, allowing the lens contents to fall through the dilated pupil into the anterior chamber where they are broken up by the use of ultrasound and aspirated out of the eye through the incision. (lookformedical.com)
  • 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)
  • Ocular cicatricial pemphigoid (OCP), commonly known as a subtype of mucous membrane pemphigoid, is a bilateral, progressive autoimmune conjunctivitis, leading to cicatrization and shrinkage of the conjunctiva with opacification of the cornea. (reviewofoptometry.com)
  • This yellowish lesion is a degeneration of elastic tissue and subepithelial collagen with hyalinized connective tissue that does not often involve the cornea. (reviewofoptometry.com)
  • transparent, avascular connective tissue that covers the anterior 1/6th of the eye. (histologyguide.com)
  • The diagnosis is made by clinical examination at the slit lamp, in which blood vessels cross the corneal limbus. (aao.org)
  • Corneal neovascularization is a condition where new blood vessels invade into the cornea from the limbus. (wikipedia.org)
  • Rather than continuing in the normal in utero fashion, the vascularization of the retina is disrupted, leading to an abnormal proliferation of blood vessels between the areas of vascularized and avascular retina. (wikipedia.org)
  • This area, termed the fovea centralis , is avascular (does not have blood vessels), and has minimal neural tissue in front of the photoreceptors, thereby minimizing light scattering. (wikipedia.org)
  • therefore, the optic nerve must cross through the retina en route to the brain. (wikipedia.org)
  • Cornea" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (wakehealth.edu)
  • The enzyme metalloproteinase degrades the cornea's basement membrane and extracellular matrix, while proteolytic enzymes allow vascular epithelial cells to enter the stromal layer of the cornea. (aao.org)
  • Chronic corneal epithelial defects can also lead to secondary bacterial ulceration, scarring and, due to restricted movement and opacification of the cornea, loss of sight. (reviewofoptometry.com)
  • Both stromal light scatter and surface epithelial irregularity contribute to degraded optical performance of the cornea and can compromise visual acuity. (iiab.me)
  • The collagen fiber bundles are arranged in concentric circles at the limbus and around the entrance of the optic nerve, elsewhere the arrangement is quite complicated. (wikidoc.org)
  • Corneal neovascularization (NV) is a pathologic condition of the cornea, characterized by the formation and extension of new vascular capillaries within and into the previously avascular corneal regions, extending from the limbus into the superficial or deep areas of the cornea. (aao.org)
  • Embryonic vasculogenesis occurs when endothelial cells precursors (hemangioblasts) begin to proliferate and migrate into avascular areas. (wikipedia.org)
  • The number of endothelial cells in the fully developed cornea decreases with age up until early adulthood, stabilizing around 50 years of age. (iiab.me)
  • Corneal endothelial cells are post-mitotic and divide rarely, if at all, in the post-natal human 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)
  • Light passing through the cornea is converged (bent) where it passes through the anterior chamber and the pupil, a circular opening regulating the amount of light entering the eye. (medscape.com)
  • 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)
  • [7] The optical properties of the cornea reside in its transparency, which in turn depends on its fibrillar and cellular arrangement. (eyewiki.org)
  • The corneal endothelium is a single layer of cells on the inner surface of the cornea . (iiab.me)
  • An ERM is a semitranslucent, avascular, fibrocellular membrane located along the inner surface of the retina's internal limiting membrane (ILM). (reviewofoptometry.com)
  • Cornea is a transparent, avascular, aspheric structure of the eye-ball.It is centrally steep and peripherally flat.It consists of 1/6th of the fibrous coat of the eyeball. (optography.org)
  • Photons within the visible spectrum (ie, light) enters the eye first by passing through the cornea, a clear, dome-shaped structure at the anterior post portion of the globe. (medscape.com)
  • avascular layer of collagen fibers and fibroblasts. (histologyguide.com)
  • The thickest layer of the cornea. (histologyguide.com)
  • 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 postnatal total endothelial cellularity of the cornea (approximately 300,000 cells per cornea) is achieved as early as the second trimester of gestation. (iiab.me)
  • This graph shows the total number of publications written about "Cornea" by people in this website by year, and whether "Cornea" was a major or minor topic of these publications. (wakehealth.edu)
  • Partial or total replacement of the CORNEA from one human or animal to another. (lookformedical.com)
  • Corneal neovascularization is a sight-threatening condition that introduces vascular pathology into the normally avascular cornea. (aao.org)
  • Corneal neovascularization is one of the most common causes of decreased visual acuity and disability for vision loss, increase in the risk of corneal graft rejection, and appearance of opacifications on the cornea. (bvsalud.org)