Topical losartan to prevent stromal scarring during post-cross-linking infection in pediatric keratoconus: A case report

Purpose: To report a pediatric case of post-corneal cross-linking (CXL) infectious keratitis successfully managed with early initiation of topical losartan to prevent corneal haze and stromal fibrosis. Case report: A 14-year-old boy developed infectious keratitis in the right eye two days after undergoing bilateral epithelium-off CXL for advanced keratoconus. Slit-lamp examination revealed a mid-peripheral ring-shaped stromal infiltrate with overlying epithelial defect, edema, and posterior fibrin. Intensive empirical antimicrobial therapy was initiated. Off-label topical losartan 0.08% was started at twice a day on day 4 post-CXL to mitigate fibrotic remodeling. The infection resolved without complications, and 0.08% topical losartan was progressively increased to four times a day for a total duration of three months. Stromal clarity improved significantly over the following weeks, with no adverse effects or recurrence in the following three months after cessation of the losartan. Conclusions and importance: This case demonstrates that early topical losartan can be safely administered in the acute phase of post-infectious keratitis in a pediatric patient. Although early use appeared to limit scar formation, the presence of a residual central corneal scar and reduced visual acuity precludes any conclusions regarding its effectiveness in improving visual outcomes. These findings suggest that timely antifibrotic therapy may influence corneal healing, but controlled studies are needed to define its efficacy, optimal timing, and dosing in both pediatric and adult populations.