Efficacy Of Topical Insulin Eye Drops In Persistent Epithelial Defects: A Cost-Effectiveness Analysis In A Refractory Cohort

Persistent epithelial defects (PEDs) are sight-threatening conditions refractory to conventional treatment, often necessitating progression to costly and invasive surgical management, such as Amniotic Membrane Transplantation (AMT) or Tarsorraphy. Topical insulin has been proposed as a non-invasive, low-cost therapeutic alternative that promotes corneal epithelial cell proliferation and wound healing. This study evaluates the clinical efficacy and cost-effectiveness of topical insulin therapy in a cohort of patients suffering from refractory PEDs.

9 patients with Persistent epithelial defect (PED) were included in this study. The mean patient age was 74.8 years ( ±8.6 years, range 65 to 93 years). Patients had failed standard management for a mean of 40.11 days (± 23.77 days, range 13 to 72 days) before insulin initiation, with a mean baseline PED area of 5.54 mm² ( ±5.19 mm², range 1.5 to 17.39 mm²).

A retrospective case series reviewing the charts of 9 consecutive patients treated with topical insulin eye drops (Humulin S 1 IU/ml in Systane, four times daily).  Outcomes included epithelization rate, time until closure, visual acuity (VA) gain, and metrics for healthcare resource consumption, specifically reductions in required NHS visits and avoidance of surgical intervention. 

Epithelization was achieved in 7 out of 9 patients (77.8%). For successful cases, the mean time to complete reepithelization was 79.43 days ( ±83.42 days, range 15 to 254 days), with a mean gain in VA of 0.40 LogMAR ( ±0.47, range 0 to 1.4 LogMAR). Of the 7 successes, 5 required Tarsorraphy and 2 required AMT (prior or concomitant to insulin); only 1 patient achieved complete epithelisation without needing either surgical intervention. The mean reduction in required clinical visits per patient was 1.89 visits (± 1.97 visits, range -1 to 5 visits), reflecting a total reduction of 17 clinical visits across the cohort. 

Topical insulin eye drops demonstrated high clinical efficacy in achieving epithelial healing even in highly complicated PEDs where prior surgical interventions had failed or were required concomitantly. The observed reduction in monitoring visits confirms that insulin therapy offers a valuable, cost-saving step by promoting healing and improving resource efficiency in these critically refractory cases.