Purpose: Glaucoma drainage implantation in conjunction with Boston Type 1 Keratoprosthesis placement is a surgical option in controlling postoperative glaucoma. The purpose of this study is to report outcomes of combined pars plana vitrectomy and glaucoma drainage implantation with corneal patch graft in Boston Type 1 Keratoprosthesis patients.
Patients and methods: A retrospective review of patients who underwent pars plana glaucoma drainage implantation in combination with Boston Type 1 Keratoprosthesis was performed. Preoperative and postoperative parameters collected and analyzed included: visual acuity, intraocular pressure, number of glaucoma medications to achieve intraocular pressure control, bandage contact lens fit, and postoperative complications.
Results: Twenty eyes of 20 patients were identified; 95% had preoperative diagnosis of glaucoma, utilizing on an average 2.5 medications with an average intraocular pressure of 19.8 mm Hg (±6.3 mm Hg; range, 9 to 32.8 mm Hg). After placement of the pars plana glaucoma drainage implant, an average intraocular pressure of 19 mm Hg (±7.0 mm Hg; range, 8 to 30 mm Hg) by scleral pneumotonometry was achieved and 85% were deemed to have normal pressures by digital palpation. An average of 2.1 intraocular pressure-lowering medications were required on last follow-up. Average follow-up was 31.6 months (±17.4 mo; range, 12.3 to 71.6 mo). Two eyes required glaucoma drainage implant explantation: one eye due to endophthalmitis from a nonhealing corneal ulcer and the other eye due to corneal melt. None of our patients experienced conjunctival erosion over a pars plana positioned glaucoma drainage implant or tube.
Conclusions: For the long-term management of glaucoma in keratoprosthesis patients, a posteriorly placed pars plana glaucoma drainage implant with corneal patch graft in conjunction with keratoprosthesis has a low risk of erosion and postoperative complications.