Background and Importance The presence of epithelial corneal ulcers due to various reasons significanttly impacts in plenty of patient‘s quality of life. Recently, the use of topical insulin has emerged as a potential alternative treatment, with promising preclinical results. However, clinical evidence remains limited.

The presence of insulin and insulin-like growth factor receptors in corneal keratocytes and epithelial cells may explain these findings.

Aim and Objectives These study aims is to assess the effectiveness and safety of insulin 1 IU/mL eye drops for persistent corneal ulcers (PCU).

Material and Methods Observational retrospective study conducted in a tertiary hospital among patients receiving topical insulin 1 IU/mL treatment for PCU between January 2021 and July 2023. Data collected included patient demographics, PCU etiology, treatment duration, prior and concurrent hospital treatments, clinical response (assessed via anterior segment biomicroscopy) and adverse effects.

Pharmacy Hospital prepared insulin eye drops at a concentration of 1 IU/mL, and were administrated 3 or 4 times daily.

Results 54 patients were treated with 1 IU/mL topical insulin for PCU, including 23 (43%) males, with a median age of 70 (58–79) years. The most common PCU etiologies were post-surgical in 11 (20.4%) patients, herpetic in 10 (18.5%), neurotrophic in 9 (16.7%), dry eye in 6 (11.1%) and infectious in 5 (9.3%) patients. 8 (14.8%) patients had diabetes.

12 (22.2%) and 16 (29.6%) patients previously received autologous serum or cyclosporine eye drops, respectively; and 9 (16.7%) and 12 (22.2%) concurrently used autologous serum or cyclosporine eye drops, respectively.

The median duration of treatment was 2,2 (1.4–5.6) months. 17 (31.5%) patients finished treatment due to PCU improvement, 6 (11.1%) due to PCU resolution, 18 (33.3) due to lack of efficacy, 1 (1.9%) due to intolerance and 7 (13.0%) continued in treatment at follow-up ending. Patients with improvement or resolution had a treatment duration of less than 5 months.

Response (PCU improvement or resolution) were better in infectious (60.0%) and post-surgical (54.5%).

Conclusion and Relevance The 1 IU/mL topical insulin eye drops formulation appears to be an effective, safe and rapid option for patients with PCU. However, treatments without effectiveness in the first 5 months do not seem to be effective. Further studies are needed to confirm these findings.

Conflict of Interest No conflict of interest.