Crocin supplementation in primary open angle glaucoma: A randomized, triple-blind, placebo-controlled clinical trial

Abstract

Purpose: Glaucoma is the leading cause of irreversible visual loss in the world. The present study was designed to evaluate the beneficial effects of crocin, as a supplement, in the management of primary open-angle glaucoma (POAG). Methods: In total, 50 POAG patients within the age range of 30–71 years with intraocular pressure (IOP) between 12 and 21 mmHg were entered into the study, and ultimately, 40 patients (49 eyes) finished the clinical trial. The participants were randomly divided into crocin and placebo groups. Patients in the crocin group received a 15 mg crocin tablet per day for four months while others, in the placebo group, received a placebo tablet per day for four months besides the main medications during the study. After four months, all patients underwent a two-month washout period. The IOP level and optical coherence tomography of the retinal nerve fiber layer (RNFL), cup-to-disc ratio (CDR), and the best-corrected visual acuity (BCVA), as the secondary outcomes, were measured at baseline, as well as four and six months later. Results: The IOP value decreased significantly in the crocin group after four (P = 0.0001) and six months (P = 0.003). The difference in CDR changes after four and six months was significant between the two groups (P = 0.00009). The crocin and placebo groups did not have a statistically significant difference regarding the changes in BCVA values and RNFL thickness (P = 0.092); however, the optical coherence tomography results showed stable conditions in the retinal nerve fiber layer. Conclusion: This study indicated that administration of crocin, as a potent neuroprotective and antioxidant ingredient of saffron, could be useful as a supplement for the prevention of the POAG progression.

Keywords

• Crocin
• Herbal medicine
• Glaucoma
• Intraocular pressure
• Visual acuity
• Primary open-angle glaucoma