Abstract
Purpose: :
To determine the prevalence and causes of low vision (LV) and blindness (BLD) in the adult population of an isolated southern island of Japan.
Methods: :
A population-based ophthalmological survey was conducted from March 2005 to August 2006 in Kumejima Island, located at 26° N, 126°'E in the East China Sea. Of all 4632 residents with age of 40 yrs or older, 3762 (response rate, 81.2%) underwent screening examination including measurement of the best-corrected visual acuity (BCVA) with a Landolt ring chart at 5 m. LV and BLD were defined as BCVA in the better eye worse than 20/60 to a lower limit of 20/400 and worse than 20/400, respectively (World Health Organization [WHO] criteria) and worse than 20/40 but better than 20/200 and 20/200 or worse, respectively (United States [US] criteria).
Results: :
The overall prevalence of LV according to the WHO and US criteria was 1.09% and 1.67%, respectively, with leading causes of cataract (0.33%), retinitis pigmentosa (0.17%), diabetic retinopathy (0.11%). The overall prevalence of BLD according to the WHO and US criteria was 0.39% and 0.75%, respectively. The primary causes were retinitis pigmentosa (0.17%) and glaucoma (0.11%). Those of monocular LV were cataract (1.10%), corneal opacity (0.19%), and retinitis pigmentosa (0.17%), while those of monocular BLD were cataract (0.29%), trauma (0.23%), and glaucoma (0.22%).
Conclusions: :
The prevalence of LV and BLD in adult residents in a southern island of Japan was 1.5 to 3 times higher than those in Tajimi City, an urban city in Japanese Main Land (Iwase et al. Ophthalmology
Clinical Trial: :
www.umin.ac.jp/ctr/index/htm [email protected]
Keywords: low vision • clinical (human) or epidemiologic studies: health care delivery/economics/manpower • visual acuity