Abstract
Purpose :
We examined the relationship between cumulative ocular ultraviolet exposure (COUV) in Chinese Han people living in a mid-latitude, subtropical and tropical areas and 5 types of cataract.
Methods :
An ocular epidemiological investigation was conducted in 1801 Chinese Han adults aged >40 (58.2±10.1yrs), comprising 636 of Taiyuan City, China (37°52′N, aged 60.4±8.9 yrs), 715 residents of Taichung City, Taiwan (24°09′N, aged 55.1±10.2 yrs), and 450 of Sanya City, China (18°15′N, aged 60.0±10.4 yrs). COUV was determined from self-reported cumulated time spent outdoors, frequency of use of glasses and/or hats, and ambient UV intensity. Cortical (COR), nuclear (NUC) and posterior subcapsular cataract (PSC) were classified by WHO classification system and waterclefts and retrodots by Kanazawa Medical University classification system under maximum mydriasis by one ophthalmologist using a slit lamp microscope. We classified cumulated UV exposure as akin to being outdoors 4 hours a day for 50 years in Taiyuan City, China with no eye protection as group COUV1; double that as group COUV2; threefold, as group COUV3 and fourfold, as group COUV4. The risks of 5 types of cataracts in groups COUV 2, 3, and 4 compared to group COUV1 were investigated using logistic regression analysis after adjusting for age, gender, diabetes and axial length.
Results :
There was no significant difference in risk of COR among all COUV groups. The risks of NUC in groups COUV2, 3 and 4 were 1.7, 6.9 and 11.5 (odds ratio for COUV1) (p<0.05). The risk of retrodots in COUV4 was 1.89 (p<0.05) and waterclefts in COUV2 and 3, 0.67 and 0.42 (p<0.05).
Conclusions :
This study indicates the possibility that Chinese Han with higher ocular UV exposure may have elevated risk of nuclear and retrodots cataracts. Since the risk of waterclefts reduced as cumulated ocular UV exposure increased, there is a possibility that indoor activities that require near vision may pose a risk of waterclefts.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.