Cataracts - Risk Factors

Highlights	Prognosis	Treatment
Introduction	Risk Factors	Resources
Causes	Prevention	References
Symptoms	Diagnosis

Risk Factors

Aging is the primary risk factor for cataracts, but other factors are alsoinvolved.

Age

Nearly everyone who lives long enough will develop cataracts to some extent. A major study reported that:

About 40% of people between 55 and 64 years old had some opaque areas in their lenses, and 5% had fully-developed cataracts
About 70% of people between 65 and 74 years old had opaque areas, and 18% had cataracts
More than 90% of people between 75 and 84 years old had opaque areas, and almost half had cataracts

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One study indicated that posterior subcapsular cataracts are the most common type in people under 70 years old, while nuclear and mixed cataracts are most common in people over 80. The risk for nuclear cataracts also increases with age.

Gender

Women face a higher risk than men. Women who started menstruating late are at an even higher risk.

Physical Features

Eye Features. People who are nearsighted and those with brown eyes may be at higher than average risk. (Not all studies, however, report a higher risk in people with darker eyes.)

Obesity and Height. Studiesare now reporting obesity as a risk factor for cataracts, notably posterior subcapsular cataracts, which form toward the back of the lens. A study of 17,150 people founda specifically higher rate of cataracts in overweight people who are tall and whose fat distribution is primarily in the abdomen.

Ethnicity

A 9-year population study, published in 2004, revealed that African Americans have nearly twice the risk of developing cataracts then whites. Analysis of the 3,000 participants also demonstrated for the first time that the risk of cortical cataracts is 3 times higher in African Americans than Caucasians. Earlier studies also identified a higher cataract risk in the black population, suggesting that it may be due to other medical illnesses, particularly diabetes. It has long been known that African Americans are much more likely to become blind from cataracts and glaucoma than white Americans, mostly due to lack of treatment.

Hispanic Americans are also at increased risk for cataracts. In fact, cataracts are the leading cause of visual impairment among Hispanics. A 2005 study found that cataracts were about 3 times more common in Hispanic patients age 65 to 84 years than in similarly aged white or African Americans. (The study evaluated Hispanic patients of Mexican descent.) As with African Americans, Hispanic patients often face barriers to access to care.