Supplementary Material for: Topical losartan treatment of herpes simplex virus- or varicella zoster virus-induced corneal scarring: A case series

Introduction: Topical losartan has emerged as a promising therapeutic option for preventing and treating corneal scarring fibrosis. Its mechanism of action involves the inhibition of ERK-mediated signaling in the non-canonical TGF beta pathways, promoting apoptosis of myofibroblasts and facilitating a return of corneal transparency. While numerous studies in rabbits and several human case reports have demonstrated its efficacy and safety, published data on its use in clinical scenarios remain limited. This study presents three cases where topical losartan successfully treated corneal scarring induced by herpes simplex virus (HSV) or varicella zoster virus (VZV) keratitis. Case Presentations: Three patients (ages 40, 38, 15 years) with corneal scarring and vision loss from HSV or VZV keratitis were treated with topical 0.8 mg/ml losartan six times a day for four to nine months, depending on the clinical response, after failing traditional management with corticosteroids. Best spectacle-corrected vision and slit lamp corneal opacity improved in each case. Anterior segment OCT documented improved stromal opacity in one case. Conclusions: Topical losartan, a known inhibitor of fibrotic TGF beta signaling, is potentially an effective alternative in the treatment of stromal scarring fibrosis caused by corneal HSV and VZV infections. Patients with HSV- or VZV-keratitis-induced corneal scarring may be ideal candidates for planned clinical trials of the efficacy and safety of topical losartan treatment.