Association Between Outdoor Daylight Exposure Duration and Primary Open-Angle Glaucoma.

PURPOSE

As a crucial environmental factor, outdoor daylight exposure has become an increasing focus in ophthalmic research. Although exploratory studies have indicated a potential connection between daylight exposure and primary open-angle glaucoma (POAG), a detailed association remains largely unknown. This study aimed to examine the association using data from the UK Biobank.

DESIGN

Combined cross-sectional and cohort study.

PARTICIPANTS

Following the application of exclusion criteria, 67 558 and 71 480 participants were included in the analysis of POAG incidence and prevalence, respectively. Additionally, 69 441 and 28 029 participants were included in the analysis of intraocular pressure (IOP) and ganglion cell complex (GCC) thickness, which are traits related to POAG.

METHODS

The initial assessment of outdoor daylight exposure duration was conducted using a standardized touchscreen questionnaire and measured in hours per day. Cox proportional hazard models were employed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for each additional hour of exposure per day. Additionally, logistic regression models and linear regression models were utilized to investigate the association with POAG prevalence and POAG-related traits, with adjustments made for multiple covariates.

MAIN OUTCOME MEASURES

POAG incidence, prevalence, and related traits.

RESULTS

After adjusting for all covariates, annual average daylight exposure duration (HR, 1.10; 95% CI, 1.02-1.18; P = .009) and summer daylight exposure duration (HR, 1.08; 95% CI, 1.02-1.14; P = .009) were associated with an increased incidence of POAG, and stronger associations were observed for males. Participants with elevated outdoor exposure duration had higher IOP levels across annual exposure (β, 0.04, 95% CI, 0.03-0.06, P < .001), summer exposure (β, 0.04, 95% CI, 0.03-0.05, P < .001), and winter exposure (β = 0.02, 95% CI, 0.01-0.04, P = .007). No association was found between outdoor daylight exposure and the prevalence of POAG or GCC thickness.

CONCLUSIONS

Prolonged daylight exposure, particularly during the summer, is associated with an elevated risk of POAG incidence, possibly due to increased IOP. These findings highlight the need for protective strategies against excessive daylight exposure.