Association between ultraviolet radiation exposure dose and cataract in Han people living in China and Taiwan: A cross-sectional study.

Hisanori Miyashita,Natsuko Hatsusaka,Eri Shibuya,Eri Kubo,Hiroshi Sasaki,Norihiro Mita,Yuki Ukai,Teppei Shibata,Mai Yamazaki,Hidetoshi Ishida,Nobuyuki Hamada

doi:10.1371/journal.pone.0215338

Abstract

PurposeWe investigated associations between ocular ultraviolet (UV) radiation exposure dose and cataract opacities among Han people living in China and Taiwan, to assess the effects of UV exposure intensity.MethodsThis cross-sectional study included Han people aged ≥40 years (1,801 individuals, 450 in Sanya, 636 in Taiyuan, and 715 in Taichung) as subjects who completed a questionnaire including items about diabetes, smoking, steroid use, work history, and time spent outdoors, and underwent an ophthalmic examination. Right eye axial length was measured using A-mode ultrasonography or IOLMaster. Slit-lamp imaging under maximum mydriasis was used to classify cataracts into three major types [cortical (COR), nuclear (NUC), and posterior subcapsular cataracts (PSC)] and two subtypes [retrodots (RD) and waterclefts (WC)] by one ophthalmologist. COR was divided into opacity presence (CEN+) or absence (CEN-) in the central 3-mm diameter area of the pupil. COR was also subdivided into three groups according to opacity shape: axle-shaped opacity concomitant with WC, wedge-shaped opacity around the pupil to the eye center, and ring-shaped opacity in the lens equator along the pupillary margin. The cumulative ocular UV exposure (COUV) was calculated. A logistic regression analysis was used for multivariate analysis.ResultsCataract odds ratios in high COUV eyes were 5.35 for NUC, 1.87 for PSC, and 1.35 for RD. In eyes with WC, risk of COR ring-shaped opacity significantly increased but that of wedge-shaped opacity (CEN+) significantly decreased. In eyes without WC, risk of COR axle-shaped opacity (CEN–) and ring-shaped opacity significantly increased but that of wedge-shaped opacity (CEN+) significantly decreased.ConclusionsIncreased COUV level among Han people may be a risk factor for the development of nuclear cataracts, PSC, retrodots and ring-shaped cortical cataract. Risk of ocular UV exposure for cortical cataract may differ by opacity shape.

Highlights

Many studies have reported ultraviolet (UV) radiation to be a risk factor for cataract [1,2,3]
Risk of ocular UV exposure for cortical cataract may differ by opacity shape
We investigated the risk of developing the five types of cataract resulting from cumulative ocular UV exposure (COUV); age, sex, Axial length (AL), and history of diabetes were considered as confounding factors

Summary

Methods

This cross-sectional study included Han people aged 40 years (1,801 individuals, 450 in Sanya, 636 in Taiyuan, and 715 in Taichung) as subjects who completed a questionnaire including items about diabetes, smoking, steroid use, work history, and time spent outdoors, and underwent an ophthalmic examination. Right eye axial length was measured using Amode ultrasonography or IOLMaster. Slit-lamp imaging under maximum mydriasis was used to classify cataracts into three major types [cortical (COR), nuclear (NUC), and posterior subcapsular cataracts (PSC)] and two subtypes [retrodots (RD) and waterclefts (WC)] by one ophthalmologist. COR was divided into opacity presence (CEN+) or absence (CEN-) in the central 3-mm diameter area of the pupil. COR was subdivided into three groups according to opacity shape: axle-shaped opacity concomitant with WC, wedge-shaped opacity around the pupil to the eye center, and ring-shaped opacity in the lens equator along the pupillary margin.

Results

Introduction

Materials and methods

Results and discussion