Epidemiology of diabetic retinopathy: expected vs reported prevalence of cases in the French population.

AIM AND METHODS Impaired eyesight and vision loss due to retinopathy are among the most feared complications in diabetic patients. As the number of diabetic patients is predicted to increase, a corresponding increase in the number of patients with diabetic retinopathy (DR) is also to be expected. This review is an update of the published literature pertaining to the epidemiology of DR. RESULTS Over the past 20 years, eight population-based studies have been conducted in Western countries using photographic evidence of DR. Their results have consistently suggested that the prevalence of DR is close to 28.7%, whereas proliferative DR and macular oedema account for 9% and 17%, respectively, of all diagnosed cases. Various longitudinal studies indicate an annual incidence of DR of 2-6%. However, in France, the epidemiology of DR has mostly been investigated by observational studies. The recorded prevalence of DR, based on physicians' reports, is estimated to be 10%, suggesting that DR is underdiagnosed in the French diabetic population. The discrepancy between the expected and reported prevalences of DR could be explained by the number of patients whose retinal status is unknown. DR screening with non-mydriatic fundus photography is effective for identifying early and advanced DR. Screening programmes carried out over the past 5 years in different regions of France indicate that 10-20% of diabetic patients with previously unknown retinal status have retinopathy. CONCLUSION Further implementation of screening programmes is the key to improving DR diagnosis and preventing vision loss in the French diabetic population.