Prevalence and Causes of Bilateral Blindness and Visual Impairment among Institutionalized Elderly People in Pamplona, Spain
To estimate the prevalence and causes of bilateral blindness and visual impairment in an urban institutionalized population aged 65 years and older.A total of 392 nursing home residents completed a standardized eye examination, including measurement of visual acuity (VA), intraocular pressure, lens opacity grading, indirect ophthalmoscopy, and photography of the macular area. The major causes of vision loss identified for all participants were blindness and visual impairment.The average subject age was 82 years (65-97); women outnumbered men 263 to 129. The prevalence of bilateral blindness (VA > or =1.0 logarithm of the minimum angle of resolution [logMAR]) was 14.9% (43/288); the prevalence of visual impairment (VA > or =0.5 and 1.0 logMAR) was 31.9% (92/288). Blindness and visual impairment increased significantly with age (p<0.05), odds ratio (OR) 1.047 and 1.088, respectively. Cataract was the most common cause of bilateral blindness and visual impairment (27.9% and 44.6%, respectively) followed by pathologic myopia (23.3%) and age-related macular degeneration (AMD) (20.9%) for blindness, and by AMD (27.2%) and pathologic myopia (12%) for visual impairment. Fifty percent of subjects with visual loss had the potential for improved vision with medical or surgical intervention.Although the prevalences were high, these data are important since it is difficult for epidemiologic studies to include aged, institutionalized individuals, although their numbers are increasing. Recognition of the predominant causes of visual loss dependent on age is fundamental for early diagnosis and treatment of ocular diseases. Many cases of low vision can be treated with appropriate ophthalmologic care.