Long-term Results of Topical Insulin Treatment for Persistent Corneal Epithelial Defects

Abstract

Purpose: To evaluate the effects of topical insulin in patients with persistent corneal epithelial defects that are refractory to the standard treatment.

Methods: A retrospective, hospital-based, clinical study was performed on 17 eyes of 16 patients with different types of refractory persistent epithelial defects who were treated with topical insulin. The treatment was continued until the defect either was resolved or persisted after three months. Patients' demographic information, etiology, comorbidities, and clinical data were reviewed. The rate of epithelial healing was considered as the primary outcome measure.

Results: Neurotrophic keratitis was the most common cause of persistent epithelial defects (58.8%), and within this category, herpetic eye disease was the main comorbidity (44.4%). The mean follow-up time was 17.91 months. Eleven out of fifteen eyes (77.3%) had complete improvement and only one patient did not respond to the treatment. The mean time of reepithelization for the eyes with full recovery was 31.27 days (ranging from 6 to 61 days). The best-corrected visual acuity improved significantly after treatment (P $<$ 0.005), and there were no reports of complications or side effects during the study period.

Conclusion: Our results suggest that topical insulin, due to its good safety profile, availability, and affordability, could be a good therapeutic alternative for persistent epithelial defects.

Keywords: Corneal ulcer; Herpetic Keratitis; Insulin; Keratitis; Cornea.

Figure 1

Slit-lamp follow-up images of patient no 6. A 46-year-old male with exposure keratopathy after long-term hospitalization due to COVID-19 pneumonia. (a & b) Irregular epithelial defects before treatment with topical insulin. (c) Six days of topical insulin leading to complete recovery of corneal epithelium.

Figure 2

Slit-lamp and anterior segment optical coherence tomography images of patient no 8 at follow-up. A 29-year-old male with a history of Mooren's ulcer, under both topical and oral corticosteroids and cyclosporin. (a & b) Deep epithelial defect even after bandage contact lens placement. (c & d) Seven days of topical insulin leading to complete recovery of corneal stroma and epithelium.

Figure 3

Slit-lamp follow-up images of patient no 11. An 84-year-old female patient with diabetes and chronic glaucoma who developed neurotrophic keratitis. (a & b) Superior epithelial defect associated with a possible vascular pannus. (c) Seven days of topical insulin leading to complete recovery of corneal epithelium.