Researchers did this study to evaluate Boston type I keratoprosthesis (KPro) surgery’s long-term visual outcomes and identify risk factors for visual failure.

The present study was a single surgeon retrospective cohort study including 85 eyes of 74 patients who underwent KPro implantation to treat severe ocular surface disease, including limbal stem cell deficiency, postinfectious keratitis, aniridia, and chemical burns. All patients with at least five years of follow-up were included in the analysis. Main outcome measures were VA, visible failure, defined as a sustained worse than preoperative VA, postoperative complications, and device retention.

Mean follow-up was 7.2±1.3 years. Mean VA was 2.1±0.7 preoperatively and 1.9±1.2 at last follow-up. There were 2.4% of patients with VA better than 20/200 preoperatively and 36.5% at last follow-up. Maintenance of improved postoperative VA was seen in 61.8% of eyes at seven years. Preoperative factors associated with visual failure were a known history of glaucoma and Stevens-Johnson syndrome.

The study concluded that approximately two-thirds of patients had improved VA 7 years after KPro implantation. Preoperative risk factors for visual failure were known as glaucoma and Stevens-Johnson syndrome.