Long-Term Outcomes of the Boston Type I Keratoprosthesis in the Management of Corneal Limbal Stem Cell Deficiency

Purpose: To report the long-term outcomes of the Boston type I keratoprosthesis (KPro) in the management of limbal stem cell deficiency (LSCD). Methods: Retrospective review of KPro procedures performed by a single surgeon from May 1, 2004, to January 1, 2015. Results: One hundred seventy-three KPro procedures were performed in 149 eyes, including 68 in 54 eyes with LSCD. Glaucoma (48% vs. 82%, P<0.0001) and a history of >= 2 keratoplasties (39% vs. 79%, P < 0.0001) were significantly less common in eyes with LSCD. Preoperative corrected distance visual acuity was >= 20/200 in 7% of eyes with LSCD and 9% of eyes without LSCD. A significantly greater percentage of eyes with LSCD had CDVA >= 20/200 at each of the first 5 years after surgery. The only postoperative complication more common in eyes with LSCD compared with eyes without was persistent corneal epithelial defect (50% vs. 28%, P = 0.013), although the associated secondary complications sterile corneal necrosis (22% vs. 11%, P = 0.059) and corneal infiltrate (20% vs. 10%, P = 0.08) were twice as common in eyes with LSCD. Despite this, the retention failure rates in eyes with and without LSCD were similar (0.089/eyeyr vs. 0.071/eye-yr; P = 0.53). Conclusions: Boston type I keratoprosthesis implantation results in a significant improvement in CDVA in the majority of eyes with LSCD through 5 years after surgery, with better visual outcomes than eyes without LSCD. Although several postoperative complications are more common in LSCD, sight-threatening complications such as endophthalmitis and retinal detachment are not. Additionally, there is no difference in the retention failure rate in eyes with and without LSCD, although a larger number of procedures with longer follow-up will be needed to determine retention outcomes more than 5 years after surgery.