Purpose:
Diabetic retinopathy (DR) is a leading cause of blindness in people of working age in developed countries. Our previous study results showed that protective effect of an angiotensin-converting enzyme inhibitor (ACEI) on DR correlates with the inhibition of "metabolic memory" phenomenon. Here, we assessed the efficacy and safety of an ACEI, captopril as compared with Vitamin C in patients with non-proliferative diabetic retinopathy (NPDR).
Methods:
In this 24-month trial, 317 type 2 diabetic patients with moderate-to-severe NPDR were randomly divided into captopril group with a dose of 12.5 mg twice a day at first 3 months and three times per day 3 months thereafter (202 patients), and Vitamin C group with a dose of 100 mg once daily (115 patients). At the end point of the trial, general clinic examinations, including blood pressure, glycated hemoglobin, and comprehensive standardized ophthalmic examinations were performed. Color fundus photography was used to grade diabetic retinopathy and optical coherence tomography (OCT) was used to detect macular edema.
Results:
A total of 83.66% of the patients in the captopril group versus 73.04% in the Vitamin C group remained unchanged in DR grading (p=0.024), and 55.45% versus 37.39% had an improved effect on the macular edema (P=0.002). The levels of blood pressure and glycated hemoglobin in the two groups of patients remained within the normal range during the entire follow-up and no significant difference was found between the baseline and last visits, suggesting that ACEI drugs play a protective effect on the diabetic retinopathy patients independent of its anti-blood pressure role.
Conclusions:
Captopril can improve or delay the development of diabetic retinopathy and macular edema, which can be used in the early treatment of type 2 diabetic patients with NPDR.
Keywords: diabetic retinopathy • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials