Cortical lens opacification in Iceland - Risk factor analysis - Reykjavik eye study

Purpose: Cortical lens opacification has been associated with outdoor expos ure and UV radiation more than other types of lens opacification, We studie d risk factors for cortical lens opacification only, the most common as web as the earliest age related change me observe in the lens, Methods: 1,045 persons, 583 females and 462 males, 50 years and older, unde rwent a detailed eye examination and answered a questionnaire. Participants with cortical lens opacification grade I, totalling 374 persons, were assi gned to case-control study I, and to case-control study LI those with corti cal lens opacification grades II and III, totalling 82 subjects. 378 age an d sex matched persons served as controls. Results: Those who spent more than 4 hours/day outside on weekdays, in thei r 20's-30's and 40's-50's respectively, were found to have increased risk o f moderate to severe cortical lens opacification, Thus the relative risk fo r grades II & IH, was 2.80 (95% CI 1.01-7.80) and 2.91 (95% CI 1.13-9.62) r espectively. Ageing and systemic cortical steroids use were also found to b e risk factors, Conclusion: Outdoor exposure appears to be associated with increased risk o f moderate to severe cortical lens opacification. Ageing is, however, the m ain risk factor.