Short-term effects of oral curcumin as adjunct to intravitreal bevacizumab in diabetic macular edema: a randomized clinical trial
In brief
Curcumin lowered HbA1c 0.63 percentage points more, but did not improve vision
In a 52-patient randomized trial, adding oral curcumin to three monthly bevacizumab injections produced a 0.63-percentage-point greater HbA1c reduction over three months than placebo. It added no measurable improvement in retinal thickness, macular volume or visual acuity, and no adverse effects were reported; whether the metabolic difference persists or benefits eye outcomes remains unknown.
- Journal
- International journal of retina and vitreous (Q1)
- Published
- 3 August 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Alireza Dehghani, Abbas Abdali, Mohammad Malekahmadi, Elaheh Foroughi, Mahsa Rafiee Alhossaini, Ali Mohammad Sabzghabaee, et al.
- PMID
- 42968188
- DOI
- 10.1186/s40942-026-00911-5
Why clinicians should know about it
- Picked for Ophthalmology (top studies of the week, 8 November 2026): Randomized trial tests adjunctive therapy for diabetic macular edema
Abstract
PURPOSE: To evaluate the efficacy of combined oral curcumin and intravitreal bevacizumab (IVB) in diabetic macular edema (DME). METHODS: This clinical trial was conducted using a parallel-group, randomized, placebo-controlled design in patients with DME. All participants received IVB at the standard dose at monthly intervals for a total of three doses. Additionally, they were assigned to receive either oral curcumin capsules (40 mg) or a matched placebo every 12 h for three months, starting at the time of the first IVB injection. Treatment efficacy was assessed by comparing changes in foveal, perifoveal, and parafoveal retinal thickness, central macular volume (CMV), and LogMAR-corrected distance visual acuity (CDVA). Hemoglobin A1c (HbA1c) tests were performed for all patients at baseline and at three months. RESULTS: Fifty-two eyes of 52 patients (26 eyes per group) completed the study. The patients' baseline characteristics were comparable between the groups. Macular thickness and CMV decreased significantly from baseline in both groups, with no statistically significant difference observed between the groups. Similarly, changes in LogMAR CDVA did not differ significantly between the intervention and control groups (MD: 0.08, [95% CI: -0.04 to 0.20]; P = 0.12). Both groups demonstrated a significant reduction in HbA1c levels at three months compared to baseline; however, the difference in HbA1c changes between the groups was statistically significant (P < 0.001), favoring the curcumin group (MD: 0.63%, 95% CI: [0.3-1.0]). No specific systemic or ocular adverse effects were observed in either group during the study. CONCLUSION: Adjunctive treatment with oral curcumin in patients receiving IVB for DME was associated with a significantly greater reduction in HbA1c levels. Despite this metabolic outcome, oral curcumin did not provide additional detectable anatomical or functional benefit over intravitreal bevacizumab alone during the three-month follow-up.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.