RxCircle

Causes and Incidence Cataracts are associated primarily with aging (senile cataracts) and chemical changes in lens proteins. Trauma, toxins, systemic disease, and intraocular inflammation are also causes. Congenital cataracts, which are rare, are the result of inborn errors of metabolism, exposure of a first-trimester fetus to rubella or toxins, and congenital anomalies. Cataracts are the third leading cause of blindness in the United States, and virtually everyone would develop cataracts if they lived long enough. More than 60% of those over 65 years of age and 90% of those over age 85 demonstrate lens opacities.

Disease Process Senile cataracts form as a result of a chemical change in the gelatinous lens protein encapsulated behind the iris. As a result, the protein coagulates, the lens gradually clouds, and normal lens fibers swell and migrate within the lens. Because of these changes, a blurred image is cast on the retina. If the condition goes untreated, the opacity eventually becomes complete and blindness results.

Symptoms Symptoms include progressive, painless blurring and distortion of objects, glare from bright lights, and gradual loss of vision. Signs include a gray or white coloring on the pupil and myopia.

Potential Complications The primary complication is blindness.

Diagnostic Tests Cataracts are identified by ophthalmoscopic or slitlamp examination.

Treatments

Surgery

Intracapsular or extracapsular removal of the lens; follow-up laser surgery to remove secondary membrane that often forms

Drugs

Topical antiinfective drugs, mydriaticcycloplegics, and hyperosmotic agents are used preoperatively; corticosteroids and mydriatics are used postoperatively

General

Corrective lenses, lens implants, and eyeglasses to correct hyperopia