Abstract
Purpose :
To compare the long-term outcomes of glaucoma drainage devices (GDD) in Boston keratoprosthesis type 1 (KPro) patients, specifically those of the Ahmed glaucoma valve (AGV) versus those of the Baerveldt glaucoma implant (BGI).
Methods :
Retrospective cohort study of 44 eyes (44 patients) implanted with a KPro between 2008 and 2017. KPro eyes with AGV (n=35) were compared to those with BGI (n=9) in the main cohort. A sub-cohort comparing KPro eyes with AGV installed pre-KPro (n=9) to those with BGI installed pre-KPro (n=7) was further examined. The primary outcome was GDD failure, defined by uncontrolled intra-ocular pressure, additional glaucoma surgery or tube removal.
Secondary outcomes included GDD related complications, change in best-corrected visual acuity (BCVA), intraocular pressure (IOP) and number of glaucoma medications.
Differences in outcomes were compared using parametric and non-parametric tests, as well as log-rank test to compare time-to-outcome events.
Results :
Mean age was 60.0±15.4 years at KPro surgery and mean follow-up time was 5.4 ±2.3 years. In the main cohort, KPro eyes with AGV had a higher cumulative failure probability over time compared to that of eyes with BGI (57.1% versus 11.1%; P=0.039). More eyes with AGV required additional glaucoma surgery procedures compared to eyes with BGI (37.1% vs. 11.1%; P=0.135). The occurrence of GDD-related complications was similar between AGV and BGI (37.1% vs 33.3%, P=0.832). Regarding BCVA, there was an improvement in 55.6% of eyes with BGI compared to 42.9% of AGV eyes (P=0.71.) Change in IOP and number of topical glaucoma medications was also comparable in both groups (P>0.05) over the follow-up period. In the subcohort, outcomes between GDDs implanted before KPro surgery were concordant with those of the main cohort.
Conclusions :
Compared to AGV, BGI implanted in KPro eyes was associated with lower GDD failure rates and slightly higher occurrence of improved BCVA while having a comparable occurrence of long-term postoperative complications.
This is a 2021 ARVO Annual Meeting abstract.