This over-production causes excess blood vessel formation in the choroid region (the choriocapillaris), which is a major cause of wet AMD. However, the RPE has a G-protein coupled receptor, GPR143, that is activated by its ligand, extracellular L-DOPA. Activation of GPR143 reduces RPE secretion of VEGF. Activation of GPR143, with the reduction in VEGF, may be the main protective role of L-DOPA against wet AMD. Management
Treatment of AMD varies depending on the category of the disease at the time of diagnosis. In general, treatment is aimed at slowing down the progression of AMD. As of 2018, there are no treatments to reverse the effects of AMD. Early-stage and intermediate-stage AMD is managed by modifying known risk factors such as smoking cessation, management of hypertension and atherosclerosis and making dietary modifications. For intermediate-stage AMD, management also includes antioxidant and mineral supplementation. Advanced-stage AMD is managed based on the presence of choroidal neovascularization (CNV): dry AMD (no CNV present) or wet AMD (CNV present). No effective treatments exist for dry AMD. The CNV present in wet AMD is managed with vascular endothelial growth factor (VEGF) inhibitors. Daily use of an Amsler grid or other home visual monitoring tools can be used to monitor for development of distorted vision, which may be a sign of disease progression.
Aphakia is the absence of the lens of the eye, due to surgical removal, such as in cataract surgery, a perforating wound or ulcer, or congenital anomaly. It causes a loss of accommodation, high degree of farsightedness (hyperopia), and a deep anterior chamber. Complications include detachment of the vitreous or retina, and glaucoma. Babies are rarely born with aphakia. Occurrence most often results from surgery to remove congenital cataract. Congenital cataracts usually develop as a result of infection of the fetus or genetic reasons. It is often difficult to identify the exact cause of these cataracts, especially if only one eye is affected. People with aphakia have relatively small pupils and their pupils dilate to a lesser degree. Causes
Surgical removal of a lens, mainly in cataract surgery, is the most common cause of aphakia. Spontaneous traumatic absorption or congenital absence of lens matter is rare. Traumatic subluxation or dislocation of a lens may cause it. Signs and symptoms
Hypermetropia: Without the focusing power of the lens, the eye becomes very farsighted. Loss of accommodation: Since the lens and its zonules are responsible for adjusting the focus of vision to different lengths, patients with aphakia will have a total loss of accommodation. Defective vision: High degree hypermetropia and total loss of accommodation cause defective vision for both distance and near. Cyanopsia: Absence of lens cause cyanopsia or blue vision. Some individuals have said that they perceive ultraviolet light, invisible to those with a lens, as whitish blue or whitish-violet. Erythropsia: Sometimes, objects appear reddish.