Assessment of the Role and Timing of Glaucoma Surgery in Boston Keratoprosthesis Type 1 Patients.

Abstract

PURPOSE\nTo determine the role and optimal timing of glaucoma surgery in relation to Boston keratoprosthesis type 1 (KPro) implantation.\n\n\nDESIGN\nRetrospective, comparative, non-randomized clinical study.\n\n\nMETHODS\nSingle-center study of a total of 100 eyes (100 patients) implanted with a KPro between 2008-2017 and diagnosed with glaucoma before or after KPro. Patients were separated into 2 groups: those with preexisting glaucoma and those who developed glaucoma de novo after KPro. Groups were then divided based on whether patients were medically or surgically managed. Glaucoma surgery included glaucoma drainage device (GDD) implantation, trabeculectomy, and cyclophotocoagulation (CPC). Primary outcomes included best-corrected visual acuity (BCVA), glaucoma progression, and complications. Differences in outcomes were compared using parametric and non-parametric tests, as well as log-rank test to compare time-to-outcome events.\n\n\nRESULTS\nAmong 72 eyes with preexisting glaucoma, 27 (38%) had glaucoma surgery before KPro (18 GDD), while 45 (62%) were medically managed only. Among the latter, 19 (42%) needed glaucoma surgery post-KPro (16 GDD). Among 28 eyes with de novo glaucoma, 12 (43%) had glaucoma surgery post-KPro (9 GDD). For eyes with preexisting glaucoma, glaucoma progression was greater with glaucoma surgery performed post-KPro (100%) compared to pre-KPro (74%, P=0.016) and to medical management (54%, P=0.002). No increase in complications were observed with glaucoma surgery compared to medications only (P>0.05), while fewer eyes maintained BCVA of 20/200 or better over time with medical management (P=0.013). Eyes with de novo glaucoma had similar progression, BCVA and complications between medical and surgical care (P>0.05).\n\n\nCONCLUSIONS\nGlaucoma surgery should be performed prior or with KPro in eyes with preexisting glaucoma. Complication rates are not increased when glaucoma surgery is performed in KPro eyes with preexisting or de novo glaucoma. To ensure optimal glaucoma control, glaucoma surgery should be performed as early as possible in KPro eyes with good visual potential.