The Association of Outdoor Activity and Age-Related Cataract in a Rural Population of Taizhou Eye Study: Phase 1 Report.

Yating Tang,Yi Lu,Lei Cai,Xiaofeng Wang,Jianming Xu,Xiaofang Ye,Yinghong Ji,Haotian Lin

doi:10.1371/journal.pone.0135870

Abstract

PurposeTo study the relationship between outdoor activity and risk of age-related cataract (ARC) in a rural population of Taizhou Eye Study (phrase 1 report).MethodA population-based, cross-sectional study of 2006 eligible rural adults (≥45 years old) from Taizhou Eye Study was conducted from Jul. to Sep. 2012. Participants underwent detailed ophthalmologic examinations including uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), intraocular pressure (IOP), slit lamp and fundus examinations as well as questionnaires about previous outdoor activity and sunlight protection methods. ARC was recorded by LOCSⅢ classification system. The prevalence of cortical, nuclear and posterior subcapsular cataract were assessed separately for the risk factors and its association with outdoor activity.ResultsOf all 2006 eligible participants, 883 (44.0%) adults were diagnosed with ARC. The prevalence rates of cortical, nuclear and posterior subcapsular cataract per person were 41.4%, 30.4% and 1.5%, respectively. Women had a higher tendency of nuclear and cortical cataract than men (OR = 1.559, 95% CI 1.204–2.019 and OR = 1.862, 95% CI 1.456–2.380, respectively). Adults with high myopia had a higher prevalence of nuclear cataract than adults without that (OR = 2.528, 95% CI 1.055–6.062). Multivariable logistic regression revealed that age was risk factor of nuclear (OR = 1.190, 95% CI 1.167–1.213) and cortical (OR = 1.203, 95% CI 1.181–1.226) cataract; eyes with fundus diseases was risk factor of posterior subcapsular cataract (OR = 6.529, 95% CI 2.512–16.970). Outdoor activity was an independent risk factor of cortical cataract (OR = 1.043, 95% CI 1.004–1.083). The risk of cortical cataract increased 4.3% (95% CI 0.4%-8.3%) when outdoor activity time increased every one hour. Furthermore, the risk of cortical cataract increased 1.1% (95% CI 0.1%-2.0%) when cumulative UV-B exposure time increased every one year.ConclusionOutdoor activity was an independent risk factor for cortical cataract, but was not risk factor for nuclear and posterior subcapsular cataract. The risk of cortical cataract increased 4.3% when outdoor activity time increased every one hour. In addition, the risk of cortical cataract increased 1.1% (95% CI 0.1%-2.0%) when cumulative UV-B exposure time increased every one year.

Highlights

Age-related cataract (ARC) remains the predominant cause of blindness all over the world, especially in China, home to 1/5 of the world’s population[1,2]
Women had a higher tendency of nuclear and cortical cataract than men (OR = 1.559, 95% confidence intervals (CI) 1.204–2.019 and Odds ratios (OR) = 1.862, 95% CI 1.456–2.380, respectively)
Adults with high myopia had a higher prevalence of nuclear cataract than adults without that (OR = 2.528, 95% CI 1.055–6.062)

Summary

Introduction

Age-related cataract (ARC) remains the predominant cause of blindness all over the world, especially in China, home to 1/5 of the world’s population[1,2]. It is very important to study the risk factors and mechanisms of cataract and to carry out some prevention work by epidemiologic method. In mainland China, most of the epidemiologic studies stress more on the prevalence of ARC and cataract surgery[3,6,7,8,9,10]. Population-based epidemiologic studies focusing on risk factors of ARC in China are still rare when compared to Unite States[11,12,13], Australia[14], Singapore[15,16] and Europe[17,18]

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Results

Conclusion