Role and timing of glaucoma surgery in Boston keratoprosthesis type 1 patients

Authors: Dominique Geoffrion, Mona Harissi-Dagher.

Disclosure Block: D. Geoffrion: None. M. Harissi-Dagher: None.

Abstract Title: Role and timing of glaucoma surgery in Boston keratoprosthesis type 1 patients

Abstract Body:

Purpose: To determine the role and optimal timing of glaucoma surgery in relation to Boston keratoprosthesis type 1 (KPro) implantation.

Study Design: Retrospective, interventional case series.

Methods: Retrospective study of a total of 100 eyes (from 100 patients) implanted with a KPro between 2008-2017 and diagnosed with glaucoma. 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.

Results: Among 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). 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).

Conclusions: Glaucoma surgery should be performed prior or concurrently to KPro in eyes with preexisting glaucoma. Complication rates are not increased when glaucoma surgery is performed in KPro eyes with de novo glaucoma. To ensure optimal IOP control, glaucoma surgery should be performed early in those eyes.