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DictionarySeecataractsenile cataract
senile cataract[‚sē‚nīl ′kad·ə‚rakt] (medicine) The most common type of cataract; it occurs with aging, and progressively blurred vision is the only symptom. senile cataract
cataract [kat´ah-rakt] opacity of the lens" >lens of the eye or its capsule. adj., adj catarac´tous.Causes and Symptoms. Some cataracts result from injuries to the eye, exposure to great heat or radiation, or inherited factors. The great majority, however, are “senile” cataracts, which are apparently a part of the aging process of the human body.
Blurred and dimmed vision are often the first symptoms. The patient may find that a brighter reading light is needed, or objects must be held closer to the eyes for better vision. Continued clouding of the lens may cause double vision; eventually there may be a need for frequent changes of eyeglasses. These symptoms do not necessarily indicate cataract, but if any of them are present, an ophthalmologist should be consulted immediately.Treatment. The only known effective treatment for cataract is surgical removal of the lens (lens extraction or cataract extraction). The procedure of choice was formerly intracapsular extraction, with total removal of the lens within its capsule. This may be done by forceps or by cryoextraction using a supercooled metal probe that forms a bond with the lens capsule. The inner portion of the lens can be removed by emulsification and aspiration. More recently the removed cataract has been replaced with a plastic intraocular lens. In this procedure the inner portions of the lens (the nucleus and cortex) may be all that is removed; the capsule is retained and the intraocular lens is placed inside it.
The lens of the eye serves only to focus light rays upon the retina. After cataract extraction the loss of the natural lens is compensated for by either special eyeglasses or contact lenses. Implantation of a permanent artificial lens, either during cataract surgery or later, is an alternative to use of cataract spectacles and a removable contact lens.Patient Care. Eye drops are administered to produce mydriasis and vasoconstriction. Because these patients may have extremely poor eyesight, care should be taken that they do not injure themselves. (See also vision.) Local anesthesia is usually preferred for the surgical procedure and preoperative medications are given to produce drowsiness. Ambulatory care surgery with same-day admission and discharge is becoming increasingly routine. Careful observation of the patient on follow-up visits is important. One needs to be on the alert for a complaint of pain in the eye followed by nausea and vomiting. These could be signs that the patient has increased intraocular pressure within the operative eye and measures need to be taken to reduce the pressure.after-cataract any membrane of the pupillary area after extraction or absorption of the lens. See also secondary cataract.atopic cataract cataract occurring, most often in the second to third decade, in those with longstanding atopic dermatitis.brown cataract (brunescent cataract) senile cataract appearing as a brown opacity.capsular cataract one consisting of an opacity of the capsule of the lens.complicated cataract secondary cataract.cortical cataract an opacity in the cortex of the lens.hypermature cataract one in which the entire lens capsule is wrinkled and the contents have become solid and shrunken, or soft and liquid.immature cataract (incipient cataract) an incomplete cataract; the lens is only slightly opaque and the cortex clear.intumescent cataract a mature cataract that progresses; the lens becomes swollen from the osmotic effect of degenerated lens protein, and this may lead to secondary angle closure (acute) glaucoma.lenticular cataract opacity of the lens not affecting the capsule.mature cataract a cataract that produces swelling and opacity of the entire lens; cataracts are removed before maturity.presenile cataract a subcapsular senile cataract in a person under 40 years of age.secondary cataract a cataract, usually posterior subcapsular, that arises from either disease (especially iridocyclitis" >iridocyclitis), degeneration (such as chronic glaucoma" >glaucoma or detachment" >retinal detachment), or surgery (such as glaucoma filtering or retinal reattachment).senile cataract cataract with no obvious cause occurring in persons over 50 years old.se·nile cat·a·racta cataract occurring spontaneously in old people; mainly a cuneiform cataract, nuclear cataract, or posterior subcapsular cataract, alone or in combination.se·nile cat·a·ract (sen'il kat'ăr-akt) A cataract occurring spontaneously in old people; mainly a cuneiform cataract, nuclear cataract, or posterior subcapsular cataract, alone or in combination. |