Topical insulin as a novel treatment for persistent epithelial defects and other ocular surface disorders: a systematic review

Abstract

Purpose: Through this systematic review, we evaluated the therapeutic potential of topical eye insulin in different concentrations to treat several surface ocular pathologies, including: persistent epithelial defects, diabetic keratopathy after a vitrectomy, neutrophic keratopathy and dry eye syndrome. We have consolidated through the data, what are the doses used, the methods of preparation for insulin, whether there are adverse effects and what would be the effectiveness of the eye drops with insulin.

Methods: We carried out an extensive search including Pubmed, Cochrane Library, Scopus and Web Of Science. We found 43 relevant studies, after which we excluded duplicates, animal studies, case reports, we ended up with 13 studies to include in the article. Through the Newcastle-Ottawa scale for observational studies and the Jadad scale for randomized controlled trials, we investigated the methodological quality of these articles.

Results: Within the review we included a significant number of 268 patients who used eye drops with insulin in concentrations from 0.5 to 2 U/ml administered typically four times per day, having an ocular benefit in corneal healing rates without adverse effects. The quality analysis of the included studies showed a NOS score of moderate-high quality, whereas the Jadad scale showed a high quality.

Conclusions: Our systematic review demonstrates that topical insulin is a promising therapeutic option for persistent epithelial defects, diabetic keratopathy following vitrectomy, neurotrophic keratopathy, and dry eye syndrome, significantly enhancing corneal healing rates with a favorable safety profile. Given its accessibility, cost-effectiveness, and potential superiority over conventional treatments, topical insulin could serve as an alternative or adjunct to therapies such as autologous serum and amniotic membrane transplantation.

Keywords: Corneal healing; Diabetic keratopathy; Dry eye disease; Epithelial defect; Neurotrophic keratopathy; Ocular surface disorder; Topical eye insulin.