Impact of Total Pars Plana Vitrectomy on Postoperative Complications in Aphakic, Snap-On, Type 1 Boston Keratoprosthesis

Purpose To determine the impact of total pars plana vitrectomies (PPVs) with peripheral shaving of the vitreous base on the rates of postoperative complications in patients with aphakic, snap-on type I Boston keratoprostheses (KPros). Design Retrospective, consecutive case series. Participants A total of 48 eyes in 46 patients with implantation of aphakic, snap-on type 1 Boston KPros performed at a tertiary care facility between January 1, 2007, and December 31, 2013, were included. Methods The cumulative incidences of postoperative complications were compared between patients who underwent total PPVs with shaving of the vitreous base (n = 22) and those who had partial PPVs or anterior vitrectomies (AVs) at the time of KPro implantation (n = 26). Main Outcome Measures Rates of complications between patients who underwent total PPVs and partial PPVs or AVs. Results The rate of total postoperative complications was lower in the total PPV group ( P = 0.018, log-rank test). In particular, eyes that underwent total PPVs had lower rates of retroprosthetic membranes (RPMs) requiring intervention ( P = 0.049) and less vision loss due to glaucoma progression ( P = 0.046). There was also a trend for fewer corneal melts ( P = 0.060) and less sight-threatening complications ( P = 0.051) in the total vitrectomy group. There was no difference in the rates of KPro extrusion ( P = 0.41), endophthalmitis or vitritis ( P = 0.15), retinal detachments ( P = 0.76), cystoid macular edema ( P = 0.83), or timing of complications between the 2 groups. The mean preoperative and postoperative visual acuities were similar between the 2 groups ( P = 0.97). The mean follow-up was 49±22 months. Conclusions Eyes that underwent total PPVs during implantation of aphakic, snap-on, type I Boston KPros had less postoperative complications than eyes with partial PPVs or AVs during the average 4 years of follow-up.