Evaluation of the monotherapy effect of crocin on mild-to-moderate diabetic retinopathy: A randomized clinical trial.

Objective: Diabetic retinopathy (DR) is asymptomatic and can lead to severe and irreversible vision loss if not treated promptly. The aim of this study was to evaluate the efficacy of crocin in mild-to-moderate DR patients whose macular center was not involved according to the early treatment diabetic retinopathy study (ETDRS) criteria. Materials and Methods: Forty patients with primary DR without involvement of the macular center were enrolled and randomized into crocin 15 mg/day and placebo groups for 3 months. At the beginning and 3 months later, best corrected visual acuity (BCVA), fasting blood sugar (FBS) and HbA1c were measured and the thickness of areas around the macula was determined. After three months, the patients were examined by an ophthalmologist and the required specialized tests were performed. Results: The mean age of the participants was 47-71 years that were 27 males and 13 females. In the intragroup comparison, the thickness around the macula was significantly reduced in the crocin group (p=0.001) compared to placebo group (p=0.67). In comparison between groups, the mean thickness of the areas around the macula at the beginning and end of the study was significantly different (p=0.046). BCVA was not significantly different after 3 months between groups. HbA1C was significantly reduced (p=0.004) in the crocin group. In this study, no specific complication due to drug use was reported. Conclusion: Based on our findings, crocin was effective in reducing the thickness of the areas around the macula in mild-to-moderate DR. It is suggested that crocin can be considered an effective supplementary drug in preventing the progression and an adjuvant therapy for DR.