Comparison of Visual and Anatomic Outcomes of Eyes Undergoing Type I Boston Keratoprosthesis with Combination Pars Plana Vitrectomy to Eyes without Combination Vitrectomy

Abstract

Purpose : To determine whether visual and anatomic outcomes after surgery combining pars plana vitrectomy, Boston keratoprosthesis and a glaucoma drainage device as needed are similar, better, or worse than Boston keratoprosthesis implantation alone.

Methods : We performed a retrospective review of adult patients undergoing Boston keratoprosthesis at our institution over an eight year interval. Visual acuity outcomes, anatomic results and complication rates of patients undergoing combination surgery (including pars plana vitrectomy and a posterior glaucoma drainage device) were compared to those undergoing keratoprosthesis placement alone.

Results : There were 70 eyes in the keratoprosthesis alone group and 55 eyes in the keratoprosthesis with pars plana vitrectomy group. Mean follow-up durations were 54.67 months in the keratoprosthesis alone group and 48.41 months in the combination group. Baseline mean Snellen equivalent visual acuities were worse for the combination group compared with the keratoprosthesis alone group (P=0.027). Visual acuities improved postoperatively by one month after keratoprosthesis implantation for both groups and improved three or more lines of Snellen acuity in the majority of eyes for both groups (>72% by 12 months). Eyes undergoing pars plana vitrectomy had lower rates of de novo (p=0.015) and significantly lower rates of secondary procedures (p=0.002) at one year. One year complications rates for retroprosthetic membrane formation, retinal detachment, hypotony, cystoid macular edema, epiretinal membrane formation, endophthalmitis and corneal melting were similar for both groups.

Conclusions : Compared with keratoprosthesis alone, combining keratoprosthesis with pars plana vitrectomy and a glaucoma drainage device as needed, resulted in lower rates of de novo glaucoma, lower rates of additional surgical procedures, similar visual acuity outcomes at one year and did not result in higher complication rates.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.