Combined use of insulin eye drops and cross-linked hyaluronic acid canalicular gel for the management of severe neurotrophic keratopathy.

PURPOSE: To describe the outcome of a novel combined therapeutic approach encompassing topical insulin eye drops and cross-linked hyaluronic acid canalicular gel in a case of severe recalcitrant neurotrophic keratopathy (NK) complicated by keratolysis.

CASE PRESENTATION: A 52-year-old male presented with a recalcitrant Mackie stage III post-herpetic NK in the right eye, characterized by a large persistent epithelial defect (PED) (area of 49.7 mm2), central stromal melting, corneal anesthesia, and neovascularization. Best-corrected visual acuity (BCVA) was reduced to hand motion. The new therapeutical approach included the withdrawal of previous therapies and the initiation of topical insulin (1 unit/mL, 4 times daily) combined with the insertion in the lower punctum of cross-linked hyaluronic acid canalicular gel (Lacrifill, Nordic Pharma, Inc., Berwyn, PA, US) to enhance ocular surface drug retention. In the subsequent follow-up visits, the PED area progressively decreased to 19.6 mm2 at 2 weeks and 4.4 mm2 at 4 weeks; complete re-epithelialization was achieved at 8 weeks. In parallel, BCVA improved to counting fingers at 1 m. No adverse events were reported.

CONCLUSIONS

The combined use of topical insulin and cross-linked hyaluronic acid canalicular gel allowed achievement of complete corneal healing in a case of severe recalcitrant NK complicated by keratolysis. The regenerative properties of insulin eye drops were enhanced by the concomitant insertion of the occlusive device. This approach represents a rational, accessible, and well-tolerated therapeutic strategy that warrants further investigation in prospective controlled studies.