Cataracts - Causes

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Glaucoma and Other Eye Conditions

Glaucoma. Glaucoma and its treatments, including certain drugs (notably miotics) and filtering surgery, pose a high risk for cataracts. The glaucoma drugs posing a particular risk for cataracts including demecarium (Humorsol), isoflurophate (Floropryl), and echothiophate (Phospholine).

Uveitis. Uveitis is chronic inflammation in the eye, which is often caused by an autoimmune disease or response. Often the cause is unknown. It is a rare condition that carries a high risk for cataracts.

Medical Disorders

A number of medical conditions appear to be associated with a higher risk for cataracts either because of a direct effect or because of the medications used for them, or both. They include the following:

• Diabetes. Cataracts in patients with diabetes appear to form when high levels of blood sugar react with proteins in the eye to form byproducts that accumulate in the lens (sugar cataracts).
• High blood pressure (hypertension).
• Autoimmune diseases including rheumatoid arthritis, psoriasis, multiple sclerosis, systemic lupus erythematosus, Behcet's disease, and others.

Genetic Factors and Other Causes of Cataracts in Children

Rarely, about once in every 10,000 births, a baby is born with cataracts (called congenital cataracts). The causes include:

• Inherited disorders are often involved in the development of congenital cataracts in children. Such cataracts are most often due to inborn abnormalities in the structure or shape of the lens, including its capsule. Dozens of variations can affect the lens causing, susceptibility to cataracts. Researchers are also investigating genetic factors that may cause mutations in alpha crystallins-- major proteins in the lens, which form cataracts. (Genetic factors also may play a role in some adult cataract cases. The exact hereditary predispositions have yet to be established.)
• Infection during pregnancy can lead to cataracts.
• Pregnant women who abuse alcohol or drugs increase the risk for cataracts (along with other more serious birth defects) in their infants.

Surgery in children with early-onset cataracts can help correct this problem in many cases, but it should be performed as soon as possible for full benefit. Experts recommend routine examination of the face of a fetus during ultrasound for abnormalities.

Review Date: 02/22/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital