Sequential versus concomitant surgery of glaucoma drainage implant and Boston keratoprosthesis type 1

Purpose: To compare sequential versus concomitant surgery of glaucoma drainage implant (GDI) and Boston keratoprosthesis type 1 (KPro). Methods: Patients who received GDI and KPro in the same eye were divided into 2 groups: GDI placement prior to KPro surgery (sequential group) or GDI placement concomitant with KPro surgery (concomitant group). Main outcome measures were GDI failure, defined as intraocular pressure (IOP) >21 mm Hg, less than a 20% IOP reduction from baseline, or IOP <5 mm Hg on 2 consecutive follow-up visits, any reoperation for glaucoma, or loss of light perception; best-corrected visual acuity (BCVA); and surgical complications. Results: Thirty-five eyes were included in the study: 17 in the sequential group and 18 in the concomitant group. The cumulative incidence of failure after 5 years of follow-up was 23.5% in the sequential group and 27.8% in the concomitant group (p = 0.250). Mean BCVA was significantly better in the concomitant group after 6 months, 1 year, 2 years, and at the last follow-up (p<0.05). Both groups had similar rates of complications (p = 1.000). The most frequent complication was GDI erosion, which occurred in 23.5% (n = 4/17) in the sequential group and in 27.8% (n = 5/18) in the concomitant group (p = 1.000). Conclusions: Glaucoma drainage implant placement at the time of KPro surgery had similar cumulative incidence of failure, but significantly favorable visual outcomes, compared to sequential surgeries. The most frequent complication was GDI erosion, occurring in approximately one fourth of the patients.