Vitreoretinal Complications in Boston Keratoprosthesis Type I and Type II Implants: Timing of Adverse Events and Long-term Outcomes

Purpose: To describe the visual, anatomical, and vitreoretinal (VR) outcomes after Boston Keratoprosthesis (BKpro) type I and type II implantation. Methods: A retrospective chart review was conducted of BKpro surgeries at Massachusetts Eye and Ear between May 2016 and November 2024. Results: Ninety-one eyes from 89 patients (mean age: 67.9 ± 16.5 years) were analyzed. The median presenting visual acuity was 2.6 logMAR [range (R): 0.38 to 4.00] that improved to 1.18 (R: 0.00–4.00). Type I BKpros (80.2%) were more common than type II (19.8%). Median duration of follow-up was 37.5 months (IQR: 16.9–67.7). VR complications were noted in 61.5% of eyes—64.3% in type I and 50.0% in type II. Complications in descending incidence include retroprosthetic membrane (8.28 events/100 years), epiretinal membrane (6.62/100 eye-years), endophthalmitis (5.24/100 eye-years), retinal detachment (4.42/100 eye-years), cystoid macular edema (4.42/100 eye-years), vitreous hemorrhage (3.59/100 eye-years), vitritis (2.48/100 eye-years), and choroidal hemorrhage (0.83/100 eye-years). Of those with VR complications, 82% had one occur in the first year. Conclusions: Both type I and type II BKpros demonstrated improved visual acuity. However, VR complication rates are high, particularly in the first year, suggesting a need for close multidisciplinary monitoring. Treatment of these sequalae remains challenging with often needing multiple procedures.