Efficacy and Safety of Topical Insulin Eye Drops for Corneal Epithelial Defects: A Systematic Review, Meta-Analysis, and Grading of Recommendations Assessment, Development, and Evaluation Assessment.

OBJECTIVES

The aim of this study was to review and meta-analyze the efficacy and safety of topical insulin eye drops (TIED) in treating corneal epithelial defects (CED).

METHODS

We registered the protocol in PROSPERO (CRD420251051879). A systematic literature search on PubMed, Cochrane, ScienceDirect, Scopus, and Google Scholar until May 2025 was done to identify controlled comparative studies. Outcomes of interest include time to complete re-epithelialization, re-epithelialization rate, treatment failure, recurrence, and adverse events. We performed meta-analysis using a random-effects model and assessed the certainty of evidence for each result using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment.

RESULTS

Seven studies involving 238 patients were included in the analysis. TIED significantly shortened re-epithelialization time (mean difference [MD] -1.20 days [-1.71--0.69], p<0.0001) and accelerated the healing rate (MD +0.26 mm2/h [0.10-0.42], p=0.002). In addition, TIED significantly reduced the risk of treatment failure (risk ratio [RR] 0.30 [0.16-0.57], p=0.003) and recurrence (RR 0.25 [0.11-0.56], p=0.0007) compared to conventional treatments, with no adverse events reported. GRADE assessments indicated very low to low certainty of evidence.

CONCLUSION

TIED may speed corneal healing, cut failures and recurrences, and is well-tolerated and inexpensive. Robust randomized controlled trials are still needed to nail down the optimal dosing, long-term safety, and its role in CED management.