Visual impairment and eye abnormalities in Oklahoma Indians

Objective: To determine the prevalence of visual impairment and eye abnormalities in Oklahoma Indians. Methods: The cross-sectional study included 1019 Oklahoma Indians, aged 48 to 82 years; 60.2% were women. All participants gave a personal inter-view, and all underwent an eye examination, including the determination of best-corrected visual acuity and an ophthalmoscopic examination. In addition, two 45 degrees fundus photographs were taken of each eye, and these photographs were graded by the Fundus Photography Reading Center at the University of Wisconsin, Madison. Results: Among the 1019 participants, 77.4% had a visual acuity of 20/20 or better, 19.5% and 2.5% had visual acuities of between 20/25 and 20/40 and between 20/50 and 20/190, respectively; and 0.6% were legally blind, all in the better eye. Cataract was the most frequent contributing cause and age-related macular degeneration the second most frequent contributing cause of visual impairment. The overall prevalence proportions of age-related macular degeneration, cataract, diabetic retinopathy, and definite glaucoma were 33.6%, 39.6%, 20.1%, and 5.6%, respectively. Most of the other eye abnormalities were rare in the study participants, except for pinguecula (42.4%) and dermatochalasis (30.1%). Conclusions: Oklahoma Indians have a higher prevalence of visual impairment, age-related macular degeneration, and diabetic retinopathy than other ethnic groups. The implementation of adequate treatment and prevention programs for eye diseases is indicated.