Prevalence of serious eye disease and visual impairment in a north London population: population based, cross sectional study

Objective: To estimate the magnitude of serious eye disorders and of visual impairment in a defined elderly population of a typical metropolitan area in England, and to assess the frequency they were in touch with, Or known to, the eye care services. Design: Cross sectional survey using two stage cluster random sampling. Setting: General practices in north London. Subjects: Random sample of people aged 65 and older, drawn from a defined population of elderly people registered with 17 general practice groups. Main outcome measures: Proportions and population prevalence estimates were determined for visual acuity, assessed with the person's own spectacles (if any), classified into four categories: prevalence of cataract, age related macular degeneration, and refractive error causing visual impairment and of definite primary open angle glaucoma; and status of contact with eye services. Results: 1547 of 1840 (84%) eligible people were examined. The population prevalence of bilateral Sampling visual impairment (visual acuity < 6/12) was 30%, of which 72% was potentially remediable. 92 of these 448 cases (21%) had visual acuity < 6/60 ("blindness") in one or both eyes. Prevalence of cataract causing visual impairment was 30%; 88% of these people were not in touch with the eye services. The prevalence of vision impairing, age related macular degeneration was 8% and of glaucoma (definite cases) was 3%. Three quarters of the people with definite glaucoma were not known to the eye services. Conclusions: Untreated visual impairment and eye disorders affect a substantial proportion of people aged 65 years and older. These findings should contribute to the setting up of future strategies for preservation of sight and eye health services in general.