4 · Mechanical, surgical adjuncts & fibrosis modulators
Topical losartan — anti-TGF-β anti-fibrotic agent
Review — modulators of corneal healing › 4 · Mechanical, surgical adjuncts & fibrosis modulators › Topical losartan — anti-TGF-β anti-fibrotic agent
Topical losartan — anti-TGF-β anti-fibrotic agent
Angiotensin II AT1 receptor antagonist, repurposed as an eye drop · work by S. Wilson (Cleveland Clinic)
Oxford IV
Weak–Moderate · emerging
Present-emerging · off-label
Mechanism of actionBlocks downstream TGF-β signaling (TGF-β→Smad pathway, via inhibition of angiotensin signaling and transactivation) → prevents differentiation of keratocytes into myofibroblasts (α-SMA) responsible for corneal fibrosis/opacity (haze). A stromal anti-scarring agent (does not accelerate epithelialization — conversely, epithelial toxicity is possible at high concentrations).
IndicationsPrevention/treatment of corneal fibrosis and opacity (haze) — best results in post-HSV/VZV scars, post-LASIK/PRK, post-infectious keratitis (Pseudomonas), post-keratectomy. A “pharmacological” alternative to mitomycin C, applicable post hoc (on an established scar) and not only intraoperatively.
Route & dosageCompounded eye drop 0.8 mg/mL, 6×/day, ≥6 months. In the presence of an epithelial defect: start at 0.2 mg/mL 6×/day until healing, then switch to 0.8 mg/mL. Toxic at high concentrations: 40 mg/mL highly toxic; 8 mg/mL → persistent epithelial defects on a compromised surface.
Level of evidenceOxford IV (case series and reports; robust preclinical basis in rabbits) · Scale: Weak–Moderate (emerging). E.g.: HSV/VZV series — VA 20/400 → 20/25 and 20/200 → 20/20; post-LASIK 20/200 → 20/30 (4 months); keratectomy: opacity 0.7 → 0.4 mm (9 months).
| FDA | Not approved for ocular use — losartan approved orally (1995, hypertension); ophthalmic use is off-label / compounded. |
|---|---|
| EU MA | Not approved for ocular use — off-label. |
| France | Off-label / compounding preparation (oral molecule widely available). |
| USA | Off-label, compounded (use is expanding). |
| Asia | Off-label; generic oral losartan available. |
Key studies: Dutra & Wilson, “Topical Losartan in the Management of Corneal Scarring Fibrosis: dosage, efficacy, epithelial toxicity,” J Ocul Pharmacol Ther 2025 — PMID 40238717 ; HSV/VZV scar series, Case Rep Ophthalmol 2025 — PMID 40248823 ; post-Pseudomonas haze (Ann Eye Sci) — DOI 10.21037/aes-24-31.