The Aurolab Keratoprosthesis (KPro) versus the Boston Type I Kpro: 5-year Clinical Outcomes in 134 Cases of Bilateral Corneal Blindness

Abstract

To compare the clinical outcomes of Boston Type I keratoprosthesis (Boston Kpro) with its low-cost version, the Aurolab Kpro (auroKPro). Retrospective comparative case series. This study included 134 eyes of 130 patients with severe bilateral corneal blindness but with wet ocular surfaces. The patients underwent either Boston Kpro (n= 78) or auroKPro (n= 56) implantation based on the device availability and patient's affordability. The primary outcome measurements were anatomical retention (defined as absence of device extrusion, exchange, or explantation) and functional recovery of 20/200 or better visual acuity at yearly time points until 5-years of follow-up. Limbal stem cell deficiency was the most common indication (60.5%) for surgery, followed by multiple failed grafts (35%). Both groups were comparable at baseline with respect to indications for surgery and associated ocular co-morbidities (P > 0.05). The overall anatomical retention rates were similar in the Boston Kpro (55 of 78, 70.5%) and auroKPro (35 of 56, 62.5%) groups (P= 0.11). Kaplan-Meier survival rates at 5 years of follow-up were greater for the Boston Kpro with respect to both anatomical retention (63 ± 6% vs. 43.4 ± 10%, respectively; P= 0.057) and functional recovery (42.4 ± 6% vs. 32.2 ± 7%, respectively; P=0.345), but these differences were not statistically significant. Complications such as intraoperative device breakage (7%) and postoperative extrusions (12.5%) were significantly more common with the auroKPro (P= 0.023). Both the auroKPro and the Boston Kpro are effective treatment options for patients with severe bilateral corneal blindness. The auroKPro can be considered an alternative to the Boston Kpro when affordability or availability of the Boston Kpro is a limiting factor.