Relationship Between Cooking Fuel and Lens Opacities in South India: A 15-Year Prospective Cohort Study.

PURPOSE: To determine whether exposure to unclean cooking fuels was associated with subsequent cataract progression as reported in previous cross-sectional studies. DESIGN: Prospective cohort study. METHODS: This is a secondary observational analysis of the community-based Antioxidants in Prevention of Cataracts trial (ClinicalTrials.gov ID NCT01664819). The exposure of interest was cooking fuel type, measured at baseline. Main outcome measures were baseline cataract severity and self-reported cataract surgery at a 15-year visit. RESULTS: Baseline and 15-year follow-up data were available for 798 and 579 participants, respectively. Wood or kerosene was used by 711 of 798 (89.1%) baseline participants, including 539 of 579 (93.1%) participants with complete follow-up. Cooking fuel type was not associated with cataract severity at baseline (P = .443). Of 8334 person-years of follow-up, 90 cataract surgeries were observed over 15 years (1.08 surgeries per 100 person-years; 95% CI = 0.87-1.32). Use of wood or kerosene was not associated with 15-year incidence of cataract surgery relative to use of propane (adjusted P = .154). Cataract surgery was more common in older individuals (HR = 1.1 per year, 95% CI = 1.1-1.2, P < .001), those with baseline myopia (HR = 2.1, 95% CI = 1.2-3.5, P = .009), and women (HR = 3.5, 95% CI = 1.2-10.1, P = .019). CONCLUSIONS: This study found no association between unclean cooking fuels and cataract progression over a 15-year period. No other modifiable risk factors were associated with incident self-reported cataract surgery.