Diabetic macular edema (DME) is one of the most important sight-threatening complications in patients with diabetes. Saffron extract contains numerous compounds, including crocin, which is the main active ingredient and antioxidant in saffron stigmas and is mostly observed as crocetin glycosides. Due to anti-inflammatory, antioxidant, neuroprotective and increasing retinal blood flow properties, crocin is thought to be useful in the treatment and prevention of diabetic maculopathy, cataract and eye diseases, wherein the inflammatory and oxidative mechanisms are involved in their pathogenesis. The aim of this trial was to evaluate the effects of crocin as a supplement on reducing inflammation in patients with diabetic maculopathy.

In this double blind placebo controlled randomized clinical trial, phase 2 study, patients with refractory diabetic maculopathy to conventional treatment were studied in 3 groups. Patients in crocin treatment groups received 5 mg or 15 mg crocin tablet per day for three month whereas patients in placebo group received one placebo tablet per day during study. The best corrected visual acuity (BCVA), and central macular thickness (CMT) were measured .

Sixty patients were enrolled in this trial and divided in three groups ( crocin 5mg , crocin 15 mg and placeb). according to our data, administration of 15 mg crocin tablet per day could significantly decrease (HbA1c) (P-value= 0.024), and CMT (P-value=0.005) and improve BCVA (Log MAR changes; P=-value=0.012) compared to placebo group (P-value<0.05). Although, administration of 5 mg crocin tablet per day could clinically improve HbA1c, FBS, CMT and BCVA, the difference was not significant compared to placebo group.

This study indicated the effect of crocin, as a potent antioxidant, in the treatment of refractory DME in short term; however, the clinical significance is yet to be proved with a study with larger sample size with longer duration of follow-up and also in treatment-naïve patients