n. the abnormal formation of new and fragile blood vessels, usually in response to ischaemia. In choroidal neovascularization, which occurs in such conditions as *macular degeneration, abnormal vessels, derived from the *choroid, form in the space between the retinal pigment epithelium (RPE) and the choroid (see retina).
a group of conditions affecting the *macula lutea of the eye, resulting in a reduction or loss of central vision. Age-related macular degeneration (AMD, ARMD) is the most common cause of poor vision in the elderly. Two types are commonly recognized. Atrophic (or dry) AMD results from chronic choroidal ischaemia: small blood vessels of the choroid, which lies beneath the retina, become constricted, reducing the blood supply to the macula. This gives rise to degenerative changes in the retinal pigment epithelium (RPE; see retina), clinically recognized by macular pigmentation and the deposition of *drusen. Wet AMD is associated with the growth of abnormal new blood vessels underneath the retina, derived from the choroid (see neovascularization). These can leak fluid and blood beneath the retina, which further reduces the macular function. Nutritional supplements can delay the progression of AMD in some cases. Laser surgery (see photocoagulation; photodynamic therapy) and anti-VEGF therapy (see vascular endothelial growth factor) can delay progression in cases of wet AMD.... macular degeneration
n. a recombinant *monoclonal antibody fragment used for the treatment of wet age-related *macular degeneration. It inhibits *vascular endothelial growth factor and therefore choroidal *neovascularization. Common side-effects are conjunctival haemorrhage, eye pain, *floaters, increased intraocular pressure, and intraocular inflammation. *Aflibercept and pegaptanib have similar uses and effects.... ranibizumab
n. any of various disorders of the retina resulting in impairment or loss of vision. It is usually due to damage to the blood vessels of the retina, occurring (for example) as a complication of longstanding diabetes (diabetic retinopathy), high blood pressure, or AIDS (AIDS retinopathy). In diabetic retinopathy, haemorrhaging or exudation may occur, either from damaged vessels into the retina or from new abnormal vessels (see neovascularization) into the vitreous humour. The later stages require laser treatment (see photocoagulation). In the UK all people with diabetes are screened using annual digital retinal photography. The warning signs of potentially sight-threatening retinal changes can be spotted and referral to a specialist eye clinic made for further assessment and intervention to prevent a deterioration in vision. Retinopathy of prematurity (ROP), formerly known as retrolental fibroplasia, is the abnormal growth of developing retinal blood vessels seen in premature infants. It may be mild and resolve spontaneously or severe enough to lead to blindness if untreated.... retinopathy
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