Abstract
Abstract: :
Purpose: To measure the cause-specific prevalence of visual impairment among a population-based sample of non-institutionalized adult Latinos in urban Los Angeles County, California. Methods: All participants aged 40 years and older in the LALES underwent a measurement of best-corrected distance logMAR visual acuity using a modified ETDRS protocol and a complete ophthalmologic examination including anterior and posterior segment photography, Humphrey visual field testing, and stereoscopic optic disc photography. Causes of visual impairment were determined after a review of all available information for each participant. Bilateral visual impairment was defined as best-corrected vision 20/40 or worse, but better than 20/200 in the better seeing eye. Cause of bilateral visual impairment in a participant was determined by cause of vision loss for the better seeing eye. Unilateral visual impairment was defined as best corrected visual acuity of 20/40 or worse but better than 20/200 in either eye. Frequency distributions of the predominant causes of visual impairment are presented here. Results: Of the 5714 participants who underwent eye examinations, 107 (1.87%) were diagnosed with bilateral visual impairment and 280 (4.9%) with unilateral visual impairment. Cataract (47%), diabetic retinopathy (17%), and age-related macular degeneration (ARMD) (14%) were the leading causes of bilateral visual impairment, followed by other retinal disorders (4%), amblyopia (4%), and glaucoma (3%). The main cause of unilateral visual impairment was cataract (41%), followed by amblyopia (13%), corneal opacity (9%), ARMD (7%), other retinal disorders (7%), myopic degeneration (5%), and diabetic retinopathy (5%). The predominant causes of visual impairment differed by age. After cataract, the leading causes of bilateral vision loss were diabetic retinopathy (10%) in the 40-64 year old group and ARMD (7%) in the >=65 year old group. The leading causes of unilateral vision impairment were cataract (14%) and amblyopia (13%) in participants 40-64 years of age and cataract (27%) and ARMD (4%) in those >=65 years. Conclusions: Consistent with other population-based studies, the principal causes of bilateral visual impairment were cataract, diabetic retinopathy, and ARMD. In contrast, cataract, amblyopia, and corneal opacities were common causes of unilateral visual impairment.
Keywords: clinical (human) or epidemiologic studies: pre • low vision • visual acuity