“Living” Eye Drops: A New Frontier in Corneal Repair

Researchers at the University of Pittsburgh are pioneering a novel approach to corneal repair using genetically modified bacteria delivered via eye drops. This innovative treatment, led by Anthony St. Leger, PhD, represents a significant step towards “living medicines” for ocular health – therapies that can continuously protect and heal tissue with a single application.

The Science Behind Living Eye Drops

The research focuses on modifying microorganisms that naturally reside on the ocular surface to release therapeutic substances. According to Dr. St. Leger, this is the “first demonstration that a microorganism that lives on the ocular surface can be genetically modified to release a drug that improves eye health.” [1] This approach aims to create a self-sustaining system for delivering anti-inflammatory compounds directly to the cornea, promoting healing and reducing the need for repeated treatments.

How it Works: Genetically Modified Bacteria

The team genetically engineers bacteria to produce and release substances that combat inflammation and support tissue regeneration. This localized drug delivery system offers several potential advantages over traditional methods, including reduced side effects and sustained therapeutic benefit. The bacteria essentially become miniature, self-contained pharmacies residing on the eye’s surface.

Research and Publications

Dr. St. Leger’s research extends beyond this groundbreaking perform on “living” eye drops. His team at the University of Pittsburgh has extensively studied the ocular microbiome and its impact on eye health, and disease. [1] Recent publications include:

• Commensal-derived Trehalose Monocorynomycolate Triggers γδ T Cell-driven Protective Ocular Barrier Immunity: Published in bioRxiv (2025). [1]
• Immunomodulation by the combination of statin and matrix-bound nanovesicle enhances optic nerve regeneration: Published in NPJ Regen Med (2024). [1]
• Living with your biome: how the bacterial microbiome impacts ocular surface health and disease: Published in Expert Rev Ophthalmol (2024). [1]
• The Secreted Ly6/uPAR-Related Protein 1 (Slurp1) Modulates Corneal Angiogenic Inflammation Via NF-κB Signaling: Published in Invest Ophthalmol Vis Sci (2024). [1]
• Genetic Manipulation of Corynebacterium mastitidis to Better Understand the Ocular Microbiome: Published in Invest Ophthalmol Vis Sci (2023). [1]

About Dr. Anthony St. Leger

Anthony St. Leger, PhD, is an Assistant Professor of Ophthalmology and Immunology at the University of Pittsburgh School of Medicine. [3] He holds a PhD in Immunology from the University of Pittsburgh and is currently a National Eye Institute, NIH Postdoctoral Fellow at the University of Pittsburgh School of Medicine. [1] His research interests center on the ocular microbiome and its role in ocular disease.

The Future of Ocular Medicine

Dr. St. Leger believes this research “opens the door to the idea of ​​a ‘living medicine’ for the eye: something that is applied once and stays, protects and helps the tissue heal.” [1] This innovative approach could revolutionize the treatment of corneal injuries and other ocular surface diseases, offering a more sustainable and effective solution for patients.