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[L. catar(r)acta, fr Gr. katarraktēs, waterfall]
An opacity of the lens of the eye, usually occurring as a result of aging, trauma, endocrine or metabolic disease, intraocular disease, or as a side effect of the use of tobacco or certain medications, e.g., steroids. Cataracts are the most common cause of blindness in adults.
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CATARACT (Courtesy of Christine Chung, MD); SEE: visual field for illus.

At first, vision is distorted, particularly during night driving or in very bright light, causing light sensitivity (photophobia). As the cataract progresses, severe visual impairment develops.

Ninety percent of adults over 65 have cataracts.

Removal of the lens is the only effective treatment. In the U.S. about 1.7 million cataract surgeries are performed annually, usually as an outpatient, same-day procedure. Typically, the lens and its anterior capsule are removed by extracapsular extraction or by phacoemulsification, leaving the posterior capsule of the lens in place, and a posterior chamber intraocular lens is inserted where the patient’s own lens used to be.
SEE: extracapsular extraction; SEE: intraocular lens; SEE: phacoemulsification

Preoperative: The procedure is explained to the patient. An antiseptic facial scrub is performed. Mydriatic and cycloplegic eye drops are instilled to dilate the pupil, followed by lidocaine jelly and betadine drops prior to surgery; osmotic diuretics may be given to reduce intraocular pressure. An intravenous access is initiated, and antibiotics, a sedative, short-acting general anesthetic, and a local anesthetic are provided.

Postoperative: The patient is instructed to wear a clear eyeshield if prescribed, and to call if experiencing pain or loss of vision. Blurred vision the day of surgery is to be expected. Eye drops are to be placed as directed and the patient should not swim or strain himself. A postoperative checkup visit is scheduled for the day following surgery. Both patient and family are taught how to inspect the eye for redness or watering and to report these conditions as well as any photophobia or sudden visual changes; wash hands well and then to instill eye drops (antibiotic to prevent inflammation and steroids to reduce infection) as prescribed; and to maintain the eye patch and shield as prescribed by the surgeon. The patient should be taught to protect the eye from bright sunlight or glare by wearing dark glasses. The patient should not swim or strain himself or herself.

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