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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 juxtafoveol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a 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 film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by 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: rods and cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible for the perception of colour through the use of a range of opsins, as well as high-acuity vision used f ... [...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. * Acral arteriolar ectasia * Corneal ectasia (secondary keratoconus), a bulging of the cornea. ;Vascular ectasias * Most broadly, any abnormal dilatation of a blood vessel, including aneurysms * Annuloaortic ectasia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bevacizumab
Bevacizumab, sold under the brand name Avastin among others, is a 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, glioblastoma, 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 inhibiting vascular endothelial growth factor A (VEGF-A), in oth ... [...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 in ...) 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 is widely used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Acuity
Visual acuity (VA) commonly refers to the clarity of vision, but technically rates an examinee's ability to recognize small details with precision. Visual acuity is dependent on optical and neural factors, i.e. (1) the sharpness of the retinal image within the eye, (2) the health and functioning of the retina, and (3) the sensitivity of the interpretative faculty of the brain. The most commonly referred visual acuity is the far acuity (e.g. 6/6 or 20/20 acuity), which describes the examinee's ability to recognize small details at a far distance, and is relevant to people with myopia; however, for people with hyperopia, the near acuity is used instead to describe the examinee's ability to recognize small details at a near distance. A common cause of low visual acuity is refractive error (ametropia), errors in how the light is refracted in the eyeball, and errors in how the retinal image is interpreted by the brain. The latter is the primary cause for low vision in people with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triamcinolone Acetonide
Triamcinolone acetonide, sold under the brand name Kenalog among others, is a synthetic corticosteroid medication used topically to treat various skin conditions, to relieve the discomfort of mouth sores, and by injection into joints to treat various joint conditions. It is also injected into 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 potent derivative of triamcinolone, and is about eight times as potent as prednisone. Most forms of triamcinolone acetonide are 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. Medical uses Triamcinolone acetonide as an intra-articular injectable has been used to treat a variety of musculoskeletal conditions. When a ... [...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 and parts of the grid may appear blank. People can first notice they suffer with the condition when looking at mini-blinds in their home. For example, straight lines might be wavy or bendy. Things may appear closer or further than they are. 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. Metamorphopsia can also lead to the misrepresentation of an object’s size or shape. It is mainly associated with macular degeneration, particularly age-related macular degeneration with choroidal neovascularization. 80%)—deposition of yellowish extracellular material in and between Bruch's membrane and retinal pigment epitheliu ... [...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 f ... [...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 growth factors. They are important signaling proteins involved in both vasculogenesis (the '' 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 can contribute to disease. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravitreal Injection
Intravitreal injection is the method of administration of drugs into the eye by injection with a fine needle. The medication will be directly applied into the vitreous humor. It is used to treat various eye diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, and infections inside the eye such as endophthalmitis. As compared to topical administration, this method is beneficial for a more localized delivery of medications to the targeted site, as the needle can directly pass through the anatomical eye barrier (e.g. cornea, conjunctiva and lens) and dynamic barrier (e.g. tears and aqueous humor). It could also minimize adverse drug effect to other body tissues via the systemic circulation, which could be a possible risk for intravenous injection of medications. Although there are risks of infections or other complications, with suitable precautions throughout the injection process, chances for these complications could be lowered. History Intravitreal in ... [...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 Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Over time, however, som ... in favor of Anti vascular endothelial growth factor therapy, 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 sig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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