Risk Factors for the Development of Cataract
Correlations for cataract development have been found, some stronger than others, within various populations and geographic locations. Increasing age was a consistent risk factor across all studies. Smoking increases the risk for nuclear sclerotic cataract and PSC. The Beaver Dam Eye Study and the Blue Mountains Eye Study, among others, concluded that there was a higher and dose-related risk of cataract development for study participants who smoked. Some smoking-related damage to the lens may be reversible upon cessation. Diabetes mellitus and exposure to ultraviolet light are also well-established and consistent risk factors for cataract development.
Additional studies have suggested hypertension, prolonged corticosteroid use (systemic, inhaled, and topical), ocular trauma (including prior ocular surgery), genetic predisposition, and high myopia as a risk factors for cataract development. Although high myopia was clearly associated with an increased incidence of nuclear cataract, all forms of myopia (low, moderate, and high) were associated with increased incidence of cataract surgery.
Studies have inconsistently associated certain other risk factors with cataract development. These factors include exogenous estrogen use, increased body mass index, and alcohol consumption. Heavy alcohol consumption increased the risk of cataract development, whereas moderate consumption may be protective.
The role of nutrition in cataract prevention (specifically, the potential benefit of antioxidant supplementation) has long been a subject of interest and controversy. Although some initial studies suggested that increased intake of vitamins C and E could be beneficial in cataract prevention, in the Age-Related Eye Disease Study 1 (AREDS1), a formulation of vitamin C, vitamin E, beta carotene, zinc, and copper did not reduce the risk of progression to cataract surgery. In a large Italian trial, use of a multivitamin and mineral supplement benefited individuals with nuclear sclerotic cataract but increased the risk of PSC development. The Age-Related Eye Disease Study 2 (AREDS2) concluded that lutein/zeaxanthin supplements had no significant overall effect on rates of progression to cataract surgery, although patients in the lowest quintile of dietary lutein/zeaxanthin intake did have a reduced risk of cataract development following supplementation.
Age-Related Eye Disease Study Research Group. Risk factors associated with age-related nuclear and cortical cataract: a case-control study in the Age-Related Eye Disease Study, AREDS Report No. 5. Ophthalmology. 2001;108(8):1400–1408.
Chew EY, SanGiovanni JP, Ferris FL, et al; Age-Related Eye Disease Study 2 (AREDS2) Research Group. Lutein/zeaxanthin for the treatment of age-related cataract: AREDS2 randomized trial report no. 4. JAMA Ophthalmol. 2013;131(7):843–850.
Mitchell P, Cumming RG, Attebo K, Panchapakesan. Prevalence of cataract in Australia: The Blue Mountains Eye Study. Ophthalmology. 1997;104(4):581–588.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.