Topical losartan for treating corneal haze after Pseudomonas keratitis: a case report

Background: Corneal scarring following bacterial keratitis, particularly from Pseudomonas infections, poses significant challenges in ophthalmic care. Current treatments often fall short in effectively reducing corneal haze and restoring vision. To our knowledge, this is the first report documenting the use of topical losartan, an angiotensin II receptor antagonist known to inhibit the transforming growth factor-β (TGF-β) pathway, for treating corneal haze resulting from bacterial keratitis. Case Description: A 30-year-old male presented with a persistent corneal scar in his right eye, 178 days post-Pseudomonas keratitis. Despite a prolonged course of topical corticosteroids, his best-corrected visual acuity (BCVA) stabilized at 20/40 with a hybrid contact lens over a 2-month period. Given the lack of improvement, we initiated treatment with topical losartan at a concentration of 0.8 mg/mL, administered six times daily. After 4 months of therapy, the patient’s BCVA improved to 20/25. Slit-lamp examination and corneal tomography revealed a significant reduction in corneal haze, indicating a positive response to the treatment. Conclusions: This case suggests that topical losartan may be a promising therapeutic option for reducing corneal opacity following bacterial keratitis by inhibiting the TGF- β pathway. However, further clinical studies are necessary to confirm its efficacy and safety in broader patient populations.