Abstract
Purpose :
The protective effect of time spent outdoors on myopia risk is well established. We investigated the association of measures related to time spent outdoors, namely adult lifetime ultraviolet B (UVB) exposure and serum Vitamin D3 (25(OH)D3), with myopia.
Methods :
EUREYE is a Europe-wide, cross-sectional, random population-based study. Participants underwent refraction and visual acuity measurement, were interviewed for adult lifetime outdoor exposure (from age 14), education, diet and medical history, and gave blood for antioxidant and 25(OH)D3 measurement. UVB exposure was calculated by combining meteorological and questionnaire data. Myopia was defined as mean spherical equivalent ≤-0.75 diopters or VA >0.3 LogMAR without optical correction. Based on 3168 participants (371 myopes, 2797 non-myopes, mean age at refraction = 72 years), we used logistic regression models to investigate the association of UVB, education and 25(OH)D3 with myopia.
Results :
Lifetime UVB exposure was associated with reduced adjusted odds ratio (OR) of myopia (0.72 per one standard deviation increase of UVB, 95% confidence interval (CI) 0.56-0.93). This association was strongest in late adolescence and early adulthood. Although individuals in the highest tertile of years of education had twice the OR of myopia (2.08, 95% CI 1.41-3.06), adjusting UVB exposure for years in education had minimal effect on the association. 25(OH)D3 was not directly associated with myopia risk, but there was an interaction between myopia, serum 25(OH)D3 and UVB with an additive effect on myopia risk for varying serum 25(OH)D3 levels. An unexpected finding was reduced odds of myopia for those with high levels of plasma lutein (5th quintile plasma lutein, OR myopia = 0.57, 95% CI 0.46-0.72).
Conclusions :
Increased UVB exposure over adult life was associated with reduced odds of myopia, independent of years of education. This effect appeared greatest in younger adults and would suggest UVB may be one of the factors that contribute to the known beneficial effects of time spent outdoors. Our findings on an interaction between serum 25(OH)D3 levels, UVB and myopia risk and also an association between high plasma lutein and myopia require confirmation.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.