Impact of topical insulin as a therapeutic intervention for corneal wounds: A comprehensive systematic review and meta-analysis

Background Persistent epithelial defects (PEDs) are challenging corneal conditions with prolonged non-healing. Commonly associated with dry eye disease and neurotrophic keratopathy, PEDs can lead to severe complications. Topical insulin has emerged as a therapeutic option, promoting epithelial healing. Methods We searched Medline, Embase, Web of Science, and Cochrane Library databases following PRISMA guidelines for studies reporting topical insulin for PEDs of any etiology and corneal epithelial defect (CEDs) post-vitrectomy. Healing time, complete wound healing (CWH), epithelization failure (EF), and epithelial healing rate were our analysis outcomes. Statistical analyses employed random-effects models and I² statistic. Results Thirteen studies involving 390 eyes were included. Mean healing time for all conditions was 20.68 days (95% CI: 11.60, 29.76) with significant heterogeneity. The pooled CWH rate was 94% (95% CI: 0.87, 0.98), with an odds ratio of 5.41 favoring topical insulin over the control group. EF was low at 5% (95% CI: 0, 0.13), and the epithelial healing rate was 0.82 mm²/hour (95% CI: 0.02, 1.62). Subgroup analyses revealed variations. Conclusions Topical insulin is effective in corneal wound healing, demonstrating high CWH rates and low failure rates. Further well-controlled studies are needed to validate these findings and assess long-term outcomes.