Prevalence and risk factors of pre-senile lens opacities in the 1969-73 Vellore Birth Cohort

Abstract Purpose To estimate the prevalence and determine predictors of lens opacities (LO) among South Asian Indians aged 41-44 years. Methods This cross sectional study included 1080 participants from the Vellore Birth Cohort, Vellore, South India. All individuals underwent anthropometric measurements, detailed ophthalmic examination including assessment of LO by LOCS III classification; and biochemical metabolic measurements. ‘Any cataract’ was defined as any opacity type with a score of >2 or evidence of cataract surgery in either eye. Questionnaire based assessments included information on ocular history, life-style factors, socio-economic and educational status, cooking fuel and sunlight exposure. Multivariable logistic regression analysis was used to examine the association between risk predictors and LO. Results The mean age (SD) of participants was 41.8 (1.0) years; 53.8% were male and 50% were rural residents. The overall prevalence of ‘any cataract’ was 13.8% (148/1075); 95% confidence interval (CI) (11.8,16.0); 59.1% (51.1, 67.4) had nuclear, 16.9% (11.2, 23.9) had cortical, 4.1%(1.5, 8.6) had posterior sub capsular, 18.9% (12.9, 26.2) had mixed cataracts; and 0.7% ( 0.02, 3.7) were pseudophakic. Increased risk for LO was observed with a history of asthma (aOR 4.51; 2.1, 9.7), HbA1C of ≥6.5% (adjusted or aOR 2.29; 95%CI 1.4, 3.7), hypertension (aOR 1.73;1.1, 2.7) and, in a subgroup (n= 372), lower 25(OH) vitamin D levels (≤20 ng/dL)(aOR 5.56; 2.3, 13.2). Conclusions A higher prevalence of LO at a younger age in South Asian Indians predicts earlier onset. History of asthma, higher HbA1C, hypertension and lower 25(OH) vitamin D levels were associated with LO.