Angiotensin-converting enzyme inhibitor therapy and diabetic retinopathy.

This pilot project suggested that angiotensin-converting enzyme (ACE) inhibitors may have an effect on delaying or reversing diabetic retinopathy. One patient who had Grade 5 (preproliferative) retinopathy improved to Grade 2 (microaneurysms only) after two years of treatment. Of the 450 patients followed in our eye and kidney clinic, no other patient showed a similar reversal from Grade 5 retinopathy without treatment. Improvement by one or more grades was seen in three other patients with variable grades of retinopathy after a mean of 3.3 years of treatment. Improvement was not related consistently to a decrease in blood pressure (0 of 4), better glycemic control (2 of 4), or reduction in albumin excretion rate (0 of 4). Proper double-blind controlled studies are needed to prove the effect of ACE inhibitors on diabetic microangiopathy of the eye.