Clinical trial evidence of medical interventions for diabetic retinopathy - Review of published randomized controlled trials

Purpose: To assess the effectiveness of medical interventions for diabetic retinopathy. Methods: Reports of relevant randomized controlled trials, published between 1985 and 2000, were identified by a systematic MEDLINE search of the medical literature and critically appraised. Results: Forty articles were identified. The findings obtained were as follows: (1) Ophthalmologic evaluation and treatment of patients from the onset of diabetes through the advanced stages of retinopathy reduces the risk of visual loss. (2) Intensive management of diabetes to maintain near-normal blood glucose levels prevents the onset of diabetic retinopathy and delays the progression of diabetic retinopathy in patients with type I diabetes. The effectiveness of maintaining near-normal blood glucose levels is not so clear in those with type 2 diabetes. (3) Strict blood pressure control reduces the risk of retinopathy. (4) Angiotensin-converting enzyme (ACE) inhibitor medications decrease the progression of retinopathy in normotensive patients with type 1 diabetes. Conclusions: A strategy to manage diabetic retinopathy based on the above-reported evidence should be adopted for all diabetic patients.