Related Experiment Video
Updated: Jul 15, 2025
Ex Vivo and In Vivo Animal Models for Mechanical and Chemical Injuries of Corneal Epithelium
Published on: April 6, 2022
Topical Losartan Decreases Myofibroblast Generation But Not Corneal Opacity After Surface Blast-Simulating Irregular
Lycia Pedral Sampaio1,2, Valeria Villabona-Martinez1, Thomas Michael Shiju1
1Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.
Purpose:
To evaluate the efficacy of topical losartan after blast injury-simulating irregular phototherapeutic keratectomy (PTK) in rabbits.
Methods:
Twelve NZW rabbits underwent 100 pulse 6.5 mm diameter PTK over a metal screen to generate severe surface irregularity and inhibit epithelial basement membrane regeneration. Corneas were treated with 0.8 mg/mL losartan in balanced salt solution (BSS) or BSS 50 µL six times per day for six weeks after PTK. All corneas had slit lamp photography, with and without 1% fluorescein at two, four, and six weeks after PTK, and were analyzed using immunohistochemistry for the myofibroblast marker α-smooth muscle actin (α-SMA), keratocyte marker keratocan, mesenchymal cell marker vimentin, transforming growth factor (TGF)-β1, and collagen type IV.
Results:
Topical 0.8 mg/mL losartan six times a day significantly decreased anterior stromal α-SMA intensity units compared to BSS at six weeks after anterior stromal irregularity-inducing screened PTK (P = 0.009). Central corneal opacity, however, was not significantly different between the two groups. Keratocan, vimentin, TGF-β1, or collagen type IV levels in the anterior stroma were not significantly different between the two groups.
Conclusions:
Topical losartan effectively decreased myofibroblast generation after surface blast simulation irregular PTK. However, these results suggest initial masking-smoothing PTK, along with adjuvant topical losartan therapy, may be needed to decrease corneal stromal opacity after traumatic injuries that produce severe surface irregularity.
Translational Relevance:
Topical losartan decreased scar-producing stromal myofibroblasts after irregular PTK over a metal screen but early smoothing of irregularity would also likely be needed to significantly decrease corneal opacity.
