The Boston Keratoprosthesis type 1 as primary penetrating corneal procedure

Penetrating keratoplasty (PK) has a poor prognosis in certain corneal eye diseases. The safety and efficacy of Boston type 1 Keratoprosthesis (KPro) surgery as a primary penetrating corneal surgery were evaluated for patients with corneal blindness and poor prognosis for PK.

In this retrospective interventional comparative study, all patients who underwent KPro implantation by a single surgeon between October 2008 and March 2011 at the Centre Hospitalier de l'Université de Montréal were divided into two groups. Thirty patients with KPro as a primary procedure (group 1) were compared with 40 patients who had PK prior to KPro (group 2). A chart review examining preoperative and postoperative best-corrected visual acuity (BCVA), intraoperative and postoperative complications and KPro retention rate over the first postoperative year was performed.

Preoperative BCVA was 20/200 or better in 10% of eyes in group 1 (range 20/150 light perception (LP)), and in 5% of eyes in group 2 (range 20/100 LP; p=0.42). BCVA was significantly better in group 1 throughout the follow-up (p<0.05). At 12 months, 87% and 63% of eyes achieved a BCVA better than 20/200 in groups 1 and 2, respectively (p<0.05). The complication rates and retention rate were similar in the two groups.

This study demonstrates that the Boston KPro implantation may be successful as a primary procedure in patients at high risk of failure with traditional PK. Further, there appears to be a visual benefit to primary KPro surgery.