Evaluating the Safety and Efficacy of Topical Insulin for Ocular Disease: A Systematic Review

Introduction: Ocular surface disorders are prevalent, impacting millions worldwide and causing significant morbidity. Conventional treatments often fall short in addressing refractory cases. Topical insulin has emerged as a potential therapeutic option. Objective: This systematic review aimed to evaluate the safety and efficacy of topical insulin for ocular diseases. Methods: We conducted a systematic review in major databases including the PubMed, MEDLINE, and EMBASE for studies published from (1976 Jan - 2024 Feb) investigating topical insulin for ocular conditions. Studies were screened and selected based on predefined inclusion/exclusion criteria. Data on safety and efficacy were extracted and analyzed. Results: Ten studies (1 case-control, 3 randomized prospective, 3 retrospective, and 3 double-blind designs) met the inclusion criteria. Studies explored various indications, including neurotrophic corneal ulcers, persistent epithelial defects, recurrent epithelial erosions, dry eye disease, and postoperative corneal wound healing in diabetic patients. Overall, findings suggested promising outcomes with topical insulin: promoting healing of refractory neurotrophic corneal ulcers, accelerating reepithelialization in persistent epithelial defects, reducing recurrence of recurrent epithelial erosions, improving symptoms and reducing corneal staining in dry eye disease, enhancing postoperative corneal epithelial wound healing in diabetic patients. Adverse events were minimal and primarily reported as transient stinging or discomfort. Conclusion: This review provides encouraging evidence for the therapeutic potential of topical insulin in diverse ocular diseases. While methodological limitations exist, particularly in non-randomized studies, the current body of literature suggests topical insulin may offer a safe and effective treatment option for patients with refractory corneal disorders. Keywords: Topical insulin, Ocular conditions, Systematic review.