Long-Term Visual Outcomes, Complications, and Retention of the Boston Type I Keratoprosthesis
To report the long-term outcomes of the Boston type I keratoprosthesis (KPro).Methods:
Data were collected regarding preoperative characteristics, surgical procedure(s) performed, and postoperative outcomes of patients who underwent KPro implantation from May 1, 2004, to May 1, 2011, and were followed for 5 years after surgery.Results:
Seventy-four KPro procedures were performed in 58 eyes (55 patients), with more than 1 KPro implanted in 10 eyes. The mean follow-up duration was 82.8 ± 20.5 months (range 57–145 months), and the most common indication for keratoprosthesis implantation was corneal transplant failure (50%). Preoperative corrected distance visual acuity (CDVA) was ≥20/200 in 5%; between 1 and 8 years after surgery, the percentage of eyes with CDVA ≥20/200 varied between 57% (4 years) and 82% (8 years). Nineteen (25.7%) KPros implanted were removed (retention failure rate 0.047/eye-year), although a KPro was retained at final follow-up in 55 eyes (94.8%). The most common postoperative complication was retroprosthetic membrane formation in 51.7% of eyes. The incidence of each postoperative complication decreased significantly over the first 10 years after surgery.Conclusions:
The KPro provides significant visual improvement in most eyes, with more than 50% regaining and maintaining 20/200 CDVA each year through 8 years after surgery. The incidence of each postoperative complication decreases significantly over the first 10 years after surgery. Although almost one-quarter of implanted keratoprostheses were removed, over 90% of eyes reaching 5 years of follow-up retain a keratoprosthesis at final follow-up.