Cataract Formation Not Associated With Unclean Cooking Fuels

Exposure to wood or kerosene cooking fuel has no effect on cataract formation, according to research published in the American Journal of Ophthalmology. 

Researchers conducted a secondary analysis of the Antioxidants in Prevention of Cataracts trial (ClinicalTrials.gov Identifier: NCT01664819) consisting of 798 patients at baseline (mean age 40.8±5.1, 61.3% women). A total of 579 patients had available  15-year follow-up data. At baseline, patients underwent comprehensive medical and ophthalmic examinations, provided demographic data, and reported the use of unclean cooking fuel (wood and kerosene). A total of 3 masked graders assessed cataract severity including nuclear opalescence, cortical opacity, and posterior subcapsular opacity, according to the Lens Opacities Classification System III scale (LOCSI II). Investigators conducted home visits at 15-year follow-up and asked participants if and when they had undergone cataract surgery. 

Overall, 89.1% of the cohort reported using unclean cooking fuels at baseline (93.1% among those who completed follow-up). Mean LOCS III scores were 2.3±0.5, 0.5±0.5, and 0.1±0.2 for nuclear, cortical, and PSC cataracts, respectively. Investigators noted that many eyes had more than 1 type of cataract. 

The team determined that using unclean cooking fuels was not associated with baseline cataract severity (P =.443). Individuals reporting wood and kerosene use did have higher rates of cataract surgery compared with those who used clean (propane) fuel (HR, 2.0; 95% CI, 0.3-11.1 and HR, 3.8; 95% CI, 0.8-19.0, respectively), but this value failed to achieve statistical significance. Researchers confirmed a strong association between age and cataract surgery rates in the analysis. 

“[T]his study did not find strong evidence that unclean cooking fuel was related to cataract severity or need for cataract surgery over 15 years in this South Indian population,” according to the researchers. However, they acknowledge that the analysis “confirmed several risk factors for cataract, strengthening confidence in the data.” 

Study limitations include the potential for geographic bias, reliance on self-reporting, and a lack of data on length of exposure to unclean fuels or ventilation conditions.    

Reference

Nesemann JM, Srinivasan M, Ravindran RD, et al. Relationship between cooking fuel and lens opacities in South India: a 15-year prospective cohort study. Am J Ophthalmol. Published online July 8, 2022. doi:10.1016/j.ajo.2022.06.021