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

Abstract

Purpose : To assess 6-year incidence and progression of age-related cataract and associated factors in a population-based cohort of Malays aged 40+ years.

Methods : Of 3,280 baseline participants of Singapore Malay Eye Study (2004-06), 1901 (72.1% of eligible) were re-examined 6 years later. Eye examinations and lens photography were performed at each visit. Cataract was assessed from lens photos following the Wisconsin Cataract Grading System. Cortical cataract was defined if total lens area involved ≥5%, nuclear cataract if nuclear opacity >standard photo #3, and posterior subcapsular (PSC) cataract if any PSC opacity present. Incidence of cataract was assessed in persons without the corresponding cataract type in either eye at baseline. Progression was assessed in eyes with any of three cataract types at baseline, and defined if at follow-up an increase by: ≥10% of lens area involved by cortical opacity, ≥1.0 grading score of nuclear cataract severity, ≥2% of lens area involved by PSC opacity, or had cataract surgery in the affected eye. Poisson regression and generalized estimating equations models (Poisson link) assessed factors associated with the incidence and progression, adjusting for age, sex, socioeconomic status (SES), ocular and systemic factors.

Results : After age standardizing to 2010 Singapore Malay population, the 6-year incidence of cortical, nuclear and PSC cataract was 14.1%, 13.6% and 8.7%, respectively. Besides age, diabetes (adjusted relative risk, RR, 1.9, 95% confidence intervals, CI, 1.4-2.6), low SES (RR 1.7, 95% CI 1.1-2.4) and C-reactive protein (RR 1.01, 95% CI 1.00-1.03 per mg/L) were associated with incident cortical cataract. Female sex was associated with increased (RR 1.5, 95% CI 1.1-2.1) while chronic kidney disease associated with decreased incident nuclear cataract (RR 0.6, 95% CI 0.4-0.9). Hypertension was associated with incident PSC cataract (RR 2.2, 95% CI 1.3-3.9).

Age-standardized progression rates were 20.4%, 5.9% and 40.6% for baseline cortical, nuclear and PSC cataract, respectively. Age was associated with decreased risk of cortical cataract progression (RR 0.94, 95% CI 0.92-0.96 per year). Diabetes was associated with increased risk of nuclear cataract progression (RR 2.2, 95% CI 1.2-4.0).

Conclusions : Consistent with findings from other populations, diabetes increases the risks of developing and progression of age-related cataract among older Malays.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.