March 2026
This article summarizes published research and clinical observations regarding topical losartan and corneal fibrosis. References to peer-reviewed studies and clinical publications are included below.
Keratoconus and Corneal Scarring
Keratoconus is a progressive corneal disorder characterized by thinning and forward protrusion of the cornea, resulting in irregular astigmatism, visual distortion, and reduced visual acuity.1 As the cornea becomes structurally weakened, progressive biomechanical changes can lead to stromal scarring and fibrosis that further impair vision.1
Although many patients achieve functional vision with rigid gas permeable or scleral contact lenses, corneal scarring complicates the clinical picture in a subset of patients and may ultimately require surgical intervention such as corneal transplantation when visual function becomes severely compromised.1
Structural changes associated with keratoconus that contribute to scarring include:
- stromal collagen thinning
- disorganization of the epithelial basement membrane
- breaks in Bowman’s layer
- progressive stromal fibrosis
These alterations disrupt the normal architecture of the cornea and contribute to the loss of transparency that affects visual quality in advanced disease.1
The Role of TGF-β in Corneal Fibrosis
At the cellular level, corneal fibrosis is strongly influenced by the transforming growth factor-beta (TGF-β) signaling pathway. TGF-β plays an important role in normal wound healing, but excessive activation of this pathway can lead to abnormal tissue remodeling and scarring.2
In a healthy cornea, epithelial and endothelial basement membranes act as barriers that prevent TGF-β from entering the stromal layer. When these membranes are disrupted by disease, injury, or surgery, TGF-β can enter the stroma and activate keratocytes and fibroblasts.1
This process promotes the formation of myofibroblasts, specialized cells that produce extracellular matrix proteins responsible for stromal haze and fibrosis.2 Persistent myofibroblast activity leads to the irregular stromal matrix and reduced transparency that characterize corneal scarring.
Because this pathway plays a central role in corneal fibrosis, researchers have investigated therapies that may inhibit TGF-β signaling.
Why Losartan Is Being Studied in Keratoconus
Losartan is an angiotensin II receptor blocker commonly used to treat hypertension. Beyond its cardiovascular effects, laboratory research has demonstrated that losartan can interfere with TGF-β signaling pathways involved in tissue fibrosis.2 By inhibiting this pathway, topical losartan may reduce the formation and persistence of corneal myofibroblasts responsible for stromal haze and fibrosis.
For this reason, investigators have explored the potential use of topical losartan in conditions involving corneal fibrosis, including:
- keratoconus with stromal scarring
- post-LASIK ectasia
- corneal haze following refractive surgery
- corneal fibrosis following injury or infection
Clinical Evidence and Studies
Research investigating topical losartan in ophthalmology has primarily focused on its ability to reduce corneal fibrosis and stromal haze.
Mechanistic research
Animal studies
Early clinical observations
Where Losartan May Fit in Keratoconus Management
Management of keratoconus typically focuses on stabilizing the cornea and improving visual function through approaches such as:
- specialty contact lenses
- corneal cross-linking
- intracorneal ring segments
- corneal transplantation in advanced disease
Because losartan targets molecular pathways involved in corneal fibrosis, it may be considered by some clinicians when stromal haze or scarring contributes to reduced visual quality. Topical losartan remains an investigational ophthalmic therapy, and treatment decisions are made at the discretion of the prescribing ophthalmologist.
Key Takeaways for Ophthalmologists
- Corneal scarring occurs in a subset of keratoconus patients and can significantly impair vision
- TGF-β signaling plays a central role in corneal fibrosis
- Losartan has demonstrated anti-fibrotic effects in laboratory and early clinical research
- Early studies suggest topical losartan may reduce corneal haze and fibrosis
- Larger clinical trials are still needed to define its role in keratoconus treatment
Compounded Losartan Eye Drops
Losartan eye drops are not commercially available and must be prepared by a compounding pharmacy when prescribed by a licensed provider. Compounding allows ophthalmologists to prescribe ophthalmic losartan formulations tailored for clinical use when appropriate.
At Massey Drugs, our pharmacists work with ophthalmologists and corneal specialists to prepare compounded ophthalmic medications and provide support when questions arise regarding formulation or prescribing.
Learn more about compounded Losartan Eye Drops and prescribing information.
Speak with a Pharmacist
If you have questions about losartan ophthalmic compounding, formulation options, or whether this therapy may be appropriate for a specific clinical scenario, our pharmacists are available to consult. Call 833-540-3500 or contact us.
References
- Kiekhafer ES, Lang JR. Painting a Clearer Picture of Corneal Scarring in Keratoconus. Modern Optometry.
- Wilson SE. Topical Losartan: Practical Guidance for Clinical Trials in Corneal Fibrosis. Translational Vision Science & Technology.
- Wilson SE. Topical Losartan for Corneal Scarring After Refractive Surgery. Cataract & Refractive Surgery Today.
- Review of Ophthalmology. Treating Corneal Fibrosis with Losartan.