Incidence, progression and risk factors of age-related cataract in Malays: The Singapore Malay Eye Study

Importance: Long-term data on age-related cataract, a leading cause of blindness and visual impairment, is scarce in Asian populations.

Background: We report the 6-year incidence and progression of age-related cataract and associated risk factors in Malay adults living in Singapore.

Design: Population-based cohort study.

Participants: A total of 3280 Malays aged 40+ years participated in baseline examinations of the Singapore Malay Eye Study (2004-2006). Six years later, 1901 (72.1% of eligible) baseline participants were re-examined.

Methods: Cataract was assessed using lens photos, taken during eye examinations, following the Wisconsin Cataract Grading System.

Main outcomes and measures: Incidence and progression of cortical, nuclear and posterior subcapsular (PSC) cataract. Poisson regression models and generalized estimating equations models (with Poisson link) were used to assess factors associated with cataract incidence and progression, respectively, adjusting for age, sex and other risk factors.

Results: Age-adjusted 6-year incidence of cortical, nuclear and PSC cataract was 14.1%, 13.6% and 8.7%, respectively, and was strongly age-related (P for trend <.001 for all types). Diabetes (relative risk [RR], 1.97; 95% confidence intervals [CI], 1.46-2.67) was associated with incident cortical cataract, hypertension was associated with PSC cataract incidence (RR, 2.09; 95% CI, 1.22-3.61), after multivariable adjustment. Progression occurred in 20.4%, 5.9% and 40.6% of baseline cortical, nuclear and PSC cataract cases, respectively.

Conclusions and relevance: Similar to other elderly populations, incidence and progression of cataract were common in this Malay population. Diabetes and hypertension were important modifiable risk factors for cataract, highlighting the importance of systemic health on eye disease.