The prevalence of low vision and blindness in a Canadian inner city

Purpose To ascertain the prevalence and primary causes of visual impairment in a sample of patients from Vancouver's downtown eastside (VDES). Materials and methods A total of 200 patients seeking nonophthalmic medical care at the Vancouver Native Health Society (VNHS) clinic in Vancouver's inner city (downtown eastside) participated in this observational case-series study. For each participant, we obtained demographic information, a medical and ocular history, and performed a complete eye exam. The prevalence of visual disability using standard North American criteria was reported. Causes of visual loss were also reported based on Canadian National Institute for the Blind (CNIB) guidelines. Results A total of 200 patients participated in our study. The median age of our sample was 46 years, 69% were male. There were very high rates of comorbid medical conditions including HIV, Hepatitis B/C, IV drug use, and diabetes. The raw prevalence of visual disability based on best-corrected visual acuity (BCVA) was 500 per 10 000; this was over nine times greater than in the general Canadian population. The raw prevalence rate of 'presenting visual disability' based on presenting visual acuity (PVA) was 2400 per 10 000. Major causes of visual disability were cataract and retinal disease. Although age-related macular degeneration and diabetic retinopathy represent major causes of vision loss in North America, no cases were noted in our sample. Conclusion The overall prevalence of visual disability was alarmingly high in this disadvantaged community. These results identify both ophthalmic disease and access to refraction and prescription spectacles as a significant health concern among people living in the VDES.