Prevalence and Causes of Blindness in a Population-Based Sample of Adult Latinos: The Los Angeles Latino Eye Study (LALES)

Abstract

Abstract: : Purpose: To determine the age-, and gender-specific prevalence and causes of blindness in a population-based sample of Latino aged 40 or older. Methods: All participants underwent a complete ophthalmologic examination, measured monocular Visual Acuity including current, Humphrey automated refraction and subjective distance refraction using a standard ETDRS protocol. Blindness were defined as 1) WHO definition (best corrected visual acuity of worse than 20/400 in the better seeing eye), and 2) U.S. definition (best corrected visual acuity of 20/200 or worse in the better seeing eye). Causes of blindness were determined by the Ophthalmologist and confirmed by a supervising Ophthalmologist after an independent review of all available information for each subject. The Chi-square test and Logistic Regression analyses were used to determine the age, gender difference and the relative risk. Results: Of 5679 participants who were examined, the overall prevalence of blindness range from 0.18% (WHO definition) to 0.44% (U.S. definition). Rate of blindness increased dramatically with age in individuals aged 80 years and older at 24 times greater risk of being blind compared to Latinos in their 40s, rates from 0.2% to 5.0% by U.S. definition (p<.0001). No gender difference was found (p=0.83). The primary causes of blindness as defined by US definition (n=25) were diabetic retinopathy (26%), age related macular degeneration (26%), retinal detachment (11%), myopic degeneration (11%), optic atrophy (11%), and cataract, corneal opacity, and other cortical blindness (5%). Conclusions: The prevalence of blindness in LALES are similar to those seen in Hispanics in Arizona and Whites in Wisconsin and Maryland. However, these rates are lower than those seen in Blacks in Barbados and Maryland. The major causes of blindness were diabetic retinopathy and age related macular degeneration. The prevalence of blindness increased with age.

Keywords: clinical (human) or epidemiologic studies: pre • visual impairment: neuro-ophthalmological dise