Prevalence of blindness and visual impairment in a population of people with diabetes

Purpose To assess the prevalence of visual impairment and the underlying ca uses in a population of people with diabetes. Method A population-based study of a defined population of people with diab etes in a district in the North West of England was done. There were 7652 k nown people with diabetes, representing 2.12% of target general population of 361 050. The main outcome measures were the prevalence of blindness and significant visual impairment (less than 6/18 corrected vision in their bet ter eye) and the underlying causes. Results Visual acuity data on 6482 (84.7%) of the 7652 individuals were obt ained. Of these, 184 had significant visual impairment (prevalence 2.84%) i ncluding 49 who were blind (vision of less than 3/60 in their better eye, p revalence 0.75%); if blindness was defined as vision less than or equal to 6/60, prevalence was 1.13% (n = 73). Details of 3 individuals could not be ascertained. Only 67 were registered, either as partially sighted (n = 42) or as blind (n = 25). In the majority (n = 133; 68%) of these 181 individua ls the visual impairment was due to causes other than diabetic retinopathy. Conclusions The prevalence of blindness and visual impairment in our popula tion of people with diabetes was low. Non-diabetic eye disease accounted fo r the majority of this visual impairment. This provides essential baseline data against which future progress can be assessed. Screening and treatment can greatly reduce the incidence of visual impairment due to diabetic reti nopathy, but its impact on overall visual impairment rates in the populatio n of people with diabetes will be more modest.