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Macular Telangiectasia
Macular telangiectasia is a condition of the retina, the light-sensing tissue at the back of the eye that causes gradual deterioration of central vision, interfering with tasks such as reading and driving. Type 1, a very rare disease involving microaneurysms in the retina, typically affects a single eye in male patients, and it may be associated with Coats' disease. Type 2 (referred to as MacTel) is the most common macular telangiectasia. It is categorized as "macular perifoveal telangiectasia", a neurodegenerative metabolic disorder, correlated with diabetes and coronary artery disease. It generally affects both eyes and usually affects both sexes equally. Type 3 is an extremely rare, poorly understood neurological disease of the retina. It is characterized by occlusion and telangiectasia of the capillaries of the fovea in one or both eyes, as well as some exudation''.'' Early research Although J. D. Gass originally identified four types of idiopathic juxtafove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. The retina serves a function which is in many ways analogous to that of the photographic film, film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by Chemical synapse, synapses and is supported by an outer layer of pigmented epithelial cells. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rod cell, rods and cone cell, cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectasia
Ectasia (), also called ectasis (), is dilation or distention of a tubular structure, either normal or pathophysiologic but usually the latter (except in atelectasis, where absence of ectasis is the problem). Specific conditions * Bronchiectasis, chronic dilatation of the bronchi. * Duct ectasia of breast, a dilated milk duct. Duct ectasia syndrome is a synonym for nonpuerperal (unrelated to pregnancy and breastfeeding) mastitis. * Dural ectasia, dilation of the dural sac surrounding the spinal cord, usually in the very low back. * Pyelectasis, dilation of a part of the kidney, most frequently seen in prenatal ultrasounds. It usually resolves on its own. * Rete tubular ectasia, dilation of tubular structures in the testicles. It is usually found in older men. * Corneal ectasia (secondary keratoconus), a bulging of the cornea. ;Vascular ectasias * Most broadly, any abnormal dilatation of a blood vessel, including aneurysms. * Annuloaortic ectasia, dilation of the aorta. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bevacizumab
Bevacizumab, sold under the brand name Avastin among others, is a monoclonal antibody medication used to treat a number of types of cancers and a specific eye disease. For cancer, it is given by slow injection into a vein (intravenous) and used for colon cancer, lung cancer, ovarian cancer, glioblastoma, hepatocellular carcinoma, and renal-cell carcinoma. In many of these diseases it is used as a first-line therapy. For age-related macular degeneration it is given by injection into the eye ( intravitreal). Common side effects when used for cancer include nose bleeds, headache, high blood pressure, and rash. Other severe side effects include gastrointestinal perforation, bleeding, allergic reactions, blood clots, and an increased risk of infection. When used for eye disease side effects can include vision loss and retinal detachment. Bevacizumab is a monoclonal antibody that functions as an angiogenesis inhibitor. It works by slowing the growth of new blood vessels by inhi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sub-Tenon Injection
Sub-Tenon injection is an ocular route of drug administration. It involves administration of a medication to the area between the sclera and the Tenon's capsule. Posterior sub-Tenons steroid injections (PSTSI) is used in the treatment of posterior ocular inflammation, such as chronic uveitis. This route is also reported to be used to administer triamcinolone acetonide (a corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...) in the treatment of macular telangiectasia type 1. Also, it is used in the ocular anesthesia. Eye Wiki. References {{Reflist[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indocyanine Green Angiography
Indocyanine green angiography (ICGA) is a diagnostic procedure used to examine choroidal blood flow and associated pathology. Indocyanine green (ICG) is a water soluble cyanine dye which shows fluorescence in near-infrared (790–805 nm) range, with peak spectral absorption of 800-810 nm in blood. The near infrared light used in ICGA penetrates ocular pigments such as melanin and xanthophyll, as well as exudates and thin layers of sub-retinal vessels. Age-related macular degeneration is the third main cause of blindness worldwide, and it is the leading cause of blindness in industrialized countries. Indocyanine green angiography is widely used to study choroidal neovascularization in patients with exudative age-related macular degeneration. In nonexudative AMD, ICGA is used in classification of drusen and associated subretinal deposits. Indications Indications for indocyanine green angiography include: * Choroidal neovascularisation (CNV): Indocyanine green angiography i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Acuity
Visual acuity (VA) commonly refers to the clarity of visual perception, vision, but technically rates an animal's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye influence the sharpness of an image on its retina. Neural factors include the health and functioning of the retina, of the neural pathways to the brain, and of the interpretative faculty of the brain. The most commonly referred-to visual acuity is ''distance acuity'' or ''far acuity'' (e.g., "20/20 vision"), which describes someone's ability to recognize small details at a far distance. This ability is compromised in people with myopia, also known as short-sightedness or near-sightedness. Another visual acuity is ''Near visual acuity, near acuity'', which describes someone's ability to recognize small details at a near distance. This ability is compromised in people with hyperopia, also known as long-sightedness or far-sightedness. A com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triamcinolone Acetonide
Triamcinolone acetonide, sold under the brand name Kenalog among others, is a synthetic compound, synthetic corticosteroid medication used topical medication, topically to treat various skin conditions, to relieve the discomfort of mouth sores, and by Joint injection, injection into joints to treat various arthropathy, joint conditions. It is also injected into lesion, lesions to treat inflammation in some parts of the body, particularly the skin. In nasal spray form, it is used to treat allergic rhinitis. It is used for the treatment of macular edema associated with uveitis. It is a more potency (pharmacology), potent derivative of triamcinolone, and is about eight times as potent as prednisone. Most forms of triamcinolone acetonide are Prescription drug, prescription drugs. In 2014, the U.S. Food and Drug Administration (FDA) made triamcinolone acetonide an over-the-counter drug in the United States in nasal spray form under the brand name Nasacort. It is available as a gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphopsia
Metamorphopsia (from , ) is a type of distorted vision in which a grid of straight lines appears wavy or partially blank. In addition, metamorphopsia can result in misperceptions of an object's size, shape, or distance to the viewer. People can first notice they suffer from the condition when looking at mini blinds in their home. Initially characterized in the 1800s, metamorphopsia was described as one of the primary and most notable indications of myopic and senile maculopathies. Metamorphopsia can present itself as unbalanced vision, resulting from small unintentional movements of the eye as it tries to stabilize the field of vision. It is mainly associated with macular degeneration, particularly age-related macular degeneration with choroidal neovascularization.Page 45 in: Other conditions that can present with complain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scotoma
A scotoma is an area of partial alteration in the field of vision consisting of a partially diminished or entirely degenerated visual acuity that is surrounded by a field of normal – or relatively well-preserved – vision. Every normal mammalian eye has a scotoma in its field of vision, usually termed its blind spot. This is a location with no photoreceptor cells, where the retinal ganglion cell axons that compose the optic nerve exit the retina. This location is called the optic disc. There is no direct conscious awareness of visual scotomas. They are simply regions of reduced information within the visual field. Rather than recognizing an incomplete image, patients with scotomas report that things "disappear" on them. The presence of the blind spot scotoma can be demonstrated subjectively by covering one eye, carefully holding fixation with the open eye, and placing an object (such as one's thumb) in the lateral and horizontal visual field, about 15 degrees from fixati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Endothelial Growth Factor
Vascular endothelial growth factor (VEGF, ), originally known as vascular permeability factor (VPF), is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, the platelet-derived growth factor family of Cystine knot, cystine-knot growth factors. They are important signaling proteins involved in both vasculogenesis (the ''De novo synthesis, de novo'' formation of the embryonic circulatory system) and angiogenesis (the growth of blood vessels from pre-existing vasculature). It is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate such as in hypoxic conditions. Serum concentration of VEGF is high in bronchial asthma and diabetes mellitus. VEGF's normal function is to create new blood vessels during embryonic development, new blood vessels after injury, muscle following exercise, and new vessels (collateral circulation) to bypass blocked vessels. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravitreal Injection
Intravitreal administration is a route of administration of a drug, or other substance, in which the substance is delivered into the vitreous humor of the eye. "Intravitreal" literally means "inside an eye". Intravitreal injections were first introduced in 1911 when Ohm gave an injection of air into the vitreous humor to repair a detached retina. In the mid-1940s, intravitreal injections became a standard way to administer drugs to treat endophthalmitis and cytomegalovirus retinitis. Epidemiology Intravitreal injections were proposed over a century ago however the number performed remained relatively low until the mid 2000s. Until 2001, intravitreal injections were mainly used to treat end-ophthalmitis. The number of intravitreal injections stayed fairly constant, around 4,500 injections per year in the US. The number of injections tripled to 15,000 in 2002 when triamcinolone injections were first used to treat diabetic macular oedema. This use continued to drive an increase to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photocoagulation
Laser coagulation or laser photocoagulation surgery is used to treat a number of eye diseases and has become widely used in recent decades. During the procedure, a laser is used to finely cauterize ocular blood vessels to attempt to bring about various therapeutic benefits. The procedure is used mostly to close blood vessels in the eye, in certain kinds of diabetic retinopathy; it is no longer used in age-related macular degeneration in favor of anti-VEGF drugs. Medical uses Diabetic retinopathy The American Academy of Ophthalmology practice guidelines recommend laser coagulation for people who have both mild to moderate nonproliferative diabetic retinopathy (NPDR) and clinically significant macular edema outside the fovea; treatment with anti-VEGF drugs is better than laser coagulation for clinically significant macular edema in the fovea. For people with severe NPDR and no macular edema, the AAO recommends laser photocoagulation for the whole retina; when there is macular ede ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
