CATARACKTSA cataracts is opacity of the lens. Some degree of cataract formation is to be expected in most people more than 70 years of age. Worldwide, catarct is the primary cause of reduced vision and blindness. More than i million catarct operations are now being performed annualy in the united states. A person with a normal life span is more likely to undergo a catarct operation than any other major surgical procedure.(CATARACKTSSebuah katarak adalah keburaman lensa. Beberapa tingkat pembentukan katarak diharapkan pada kebanyakan orang lebih dari 70 tahun. Di seluruh dunia, catarct adalah penyebab utama berkurangnya penglihatan dan kebutaan. Lebih dari i juta operasi catarct sekarang sedang dilakukan setiap tahunnya di Amerika Serikat. Seseorang dengan jangka hidup yang normal lebih mungkin untuk menjalani operasi catarct daripada prosedur pembedahan besar lainnya)The most common cataract is the age-related or snile type. Senile ususally begin around the age of 50 years and consist of cortical, nuclear, or posterior. Subcapsular opacities, which may coexist in various combination. In cortical catarct, spoke-like opacifications are found in the periphery of the lens. They progress slowly, infrequenly involve the visual axis, and often do not cause severe loss of vision. Nuclear sclerotic catarct are result of a progressive yellowing and hardening of the central lens (nucleus). Most people older than 70 have some degree of nuclear sclerosis. Posterior lens capsula and cause visual loss early in their development because they lie directly on the visual axis.Katarak yang paling umum adalah jenis usia terkait atau pikun. Pikun biasanya mulai sekitar usia 50 tahun dan terdiri dari korteks, nuklir, atau posterior. Kekeruhan subkapsular, yang dapat hidup berdampingan dalam berbagai kombinasi. Dalam catarct kortikal, berbicara seperti opacifications ditemukan di pinggiran lensa. Mereka maju perlahan-lahan, infrequenly melibatkan sumbu visual, dan sering tidak menyebabkan hilangnya berat visi. Nuklir catarct sklerotik adalah hasil dari menguning progresif dan pengerasan lensa pusat (inti). Kebanyakan orang tua dari 70 memiliki beberapa tingkat sclerosis nuklir. Posterior capsula lensa dan menyebabkan hilangnya penglihatan awal perkembangan mereka karena mereka berbaring langsung pada sumbu visual

Etiolgy and risk factorsThe cumulative exposure to ultraviolet light over a persons life span is the single most important risk factor in catarct development. People whi live at high altitudes or who work in bright sunlight, such as commercial fishermen, appear to oxperience cataract formation earlier in life. Glassblowers and welders who do not wear eye protection are also at hinger risk.

Cataract may delelop as a result of many other systemic, acular, and congenital disorders. Systemic disorders include diabetes, tetany, myotonic dystrophy, neurodermatitis, galactosemia, lowe syndrome, wenners syndrome and down syndrome. Intraocular disorders include iridocyclitis, renitis, retinal detachment, and onchocerciasis. Infection (german measles, mumps, hepatis, poliomyelitis, chicikenpox, infection mononuclesosis) during the first trimester of pregenancy may cause congentinal cataract. Blunt trauma, lacerations, foreign bodies, radiation, exposure to infraded light, and chronic use of corticosteroid may also result in cataract.PathophysiologyCataract formation is chtaracterized chemilly by a reduction in oxygen uptake and an initial increase in water content followed by dehydreation of the lens. Si=odium and calcium contects are increased, potassium ascorbic acid, and protein contents are decreased. The protein in the lens undergoes numerous age-related changes ,including yellowing from formation of fluorescent compounds and molecular changes changes. These changes, along with the photoabsorption of cataract may be caused by a photochermical process.Cataract progress in predictable pattern, they begin as immanuture cataract that are not complectly opaque and some light is transmitted throught them, allowing useful vision. Mature cataract are completely opaque ( the former term for this stage was ripe). Vision in significantly reduced. Hypermature cataract are those in which the lens proteins break down into short-chain polypeptides that leak out through the lens capsule. The pieces of protein are enguifedby macrophages, which may obstruct the trabecular meshwork, causing phacolytic glaucoma.ComplicationPostoperative infection, bleeding, macular edema, and wound leaks are possible, however, side effect, after cataract surgery are rare. The incidence or retinal detachment is hinger in the 12 months after cataract surgery.