A new study from researchers at UHN’s Donald K. Johnson Eye Institute (DKJEI) found that a non‑surgical approach can effectively manage corneal damage and thinning, helping reduce the risk of vision loss. The findings clarify how different treatment options compare and underscore the importance of careful clinical assessment to avoid unnecessary invasive procedures.
The integrity of the cornea—the transparent tissue covering the front of the eye—is vital for vision and overall eye health. Perforations (holes) or thinning of the cornea require urgent treatment to prevent vision loss, or in severe cases, loss of the eye itself.
Cyanoacrylate tissue adhesive (CTA), a specialized medical glue, is commonly used as a first-line treatment for corneal thinning or perforation. If CTA alone is insufficient to restore the cornea's integrity, some patients subsequently undergo a corneal transplant, called penetrating keratoplasty (PKP). Previous studies, however, have not clearly established whether outcomes differ between patients who receive PKP and those treated with CTA alone.
To determine whether PKP offers additional benefits, Dr. Clara Chan, a Clinician Investigator at DKJEI, and her team evaluated 189 cases of corneal thinning or perforation. Of these, 125 received CTA alone and 64 received CTA followed by PKP.
The researchers found that post-treatment vision outcomes were similar between groups, even though individuals who underwent PKP had more advanced disease at baseline. Patients requiring PKP were more likely to have a condition that impaired healing or caused inflammation, such as a viral infection. They also found that individuals who ultimately underwent PKP had typically received multiple CTA applications, suggesting that the number of applications may signal the need for surgical intervention.
Overall, the study reinforces CTA as an effective first‑line treatment for corneal perforation and thinning. This is particularly valuable for centres without the capacity to perform PKP. The findings also highlight the importance of tailoring treatment to each patient’s needs—whether CTA alone or CTA followed by PKP—to ensure effective care while minimizing unnecessary surgical risks.
The first author of this study is Ryan Huang, a Doctor of Medicine candidate at the University of Toronto’s Temerty Faculty of Medicine.
Dr. Clara Chan is the senior author of this study. Dr. Chan is a Clinician Investigator at UHN’s Donald K. Johnson Eye Institute, an Associate Professor of Ophthalmology and Vision Sciences at the University of Toronto’s Temerty Faculty of Medicine, and the Medical Director of the Ontario Division of The Eye Bank of Canada.
This work was supported by the UHN Foundation.
Dr. Clara Chan has previously received funds as a consultant from several companies including Abbvie, Bausch & Lomb, Johnson & Johnson Vision, and Labtician Ophthalmics Inc. She has also received research grant support from Aurion, Corneat, and Claris Bio. For a complete list of competing interests, please see the publication.
Huang RS, Agarwal M, Mimouni M, Chan CC. Comparative effectiveness of penetrating keratoplasty and conservative cyanoacrylate tissue adhesive application for corneal perforation and thinning. Eye (Lond). 2026 Jan 8. doi: 10.1038/s41433-025-04201-6. Epub ahead of print.