Successful Müller Muscle–Conjunctiva Resection in Patients With Boston Keratoprosthesis Type I

Abstract

To present a case series of patients with Boston keratoprosthesis type I (KPro) who have had successful ptosis repair with Müller muscle-conjunctiva resection (MMCR). Patients with KPros managed with MMCR for ptosis were identified. Records were examined to obtain preoperative and postoperative visual acuity, KPro viability, and eyelid measurements including margin-to-reflex distance 1 (MRD1), levator function, and lagophthalmos. Seven eyes of 6 patients with KPros and ptosis treated with MMCR were identified. Four eyes underwent a lower lid tarsal strip procedure concurrently with the MMCR to minimize the risk of exposure to the graft postoperatively. The average time between KPro surgery and ptosis surgery was 29.1 months (range, 4-79 months). Preoperatively, the average MRD1 was -2.4 mm and the average levator function was 11.3 mm. Postoperatively, all eyelids were elevated and the average MRD1 was 0.9 mm. One eye had 0.5 mm of lagophthalmos noted whereas all other eyes had no lagophthalmos. The average follow-up time was 25.9 months (range, 13-41 months). All 7 eyes maintained a viable KPro without any compromise to the conjunctiva or donor corneal tissue. This retrospective case series describes 7 eyes with KPros that underwent successful MMCR without compromise to the integrity of the KPro. Because these patients are at high risk for potential complications, we recommend careful patient selection, a goal of undercorrection, and consideration of supplemental procedures to the lower eyelids to minimize complications to the KPro.