Topical Losartan in the Treatment of Stromal Scarring After Refractive Surgery.

Purpose: To review current guidelines for the prophylactic and therapeutic use of topical losartan to prevent and treat corneal scarring fibrosis in refractive surgery.

Methods: PubMed was used to search the medical literature.

Results: Scarring fibrosis of the cornea is typically associated with injury to, and defective regeneration of, the adjacent overlying epithelial basement membrane that controls transforming growth factor (TGF)-β passage into the stroma, leading to the development and persistence of myofibroblasts. Topical losartan's effects in the cornea are mediated by inhibiting activation of the intracellular signaling molecule extracellular signal-regulated kinase that modulates the responses of TGF-β derived primarily from the tears and epithelium on stromal myofibroblasts in anterior corneal injuries. Topical losartan can be used prophylactically by surgeons who avoid mitomycin C (MMC) in cases with higher correction or other factors associated with the development of "late haze" corneal fibrosis. It has also been effective in the treatment of scarring stromal fibrosis once it develops as late haze after photorefractive keratectomy (PRK), breakthrough late haze that occurs despite the use of intraoperative MMC, complicated laser in situ keratomileusis and small incision lenticule extraction cases, the development of visually significant incisional fibrosis after radial keratotomy and astigmatic keratotomy, and in corneas with persistent epithelial defects after any refractive surgical procedure. Cases with bilateral late haze after PRK are less likely to respond to topical losartan due to the underlying defect that originally led to the development of fibrosis affecting the losartan two-phase mechanism of action.

Conclusions: Topical losartan has an important role in the refractive surgery armamentarium to prevent or treat scarring fibrosis in the corneal stroma. [J Refract Surg. 2025;41(6):e602-e610.].