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).

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.

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.

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.