Incidence and Outcomes of Hypertensive Phase After Glaucoma Drainage Device Surgery

Abstract

Purpose: To describe the incidence, risk factors, clinical characteristics, and long-term outcomes of a hypertensive phase (HP) after glaucoma drainage device (GDD) implantation.

Design: Retrospective cohort study.

Participants: Eyes that underwent implantation of their first GDD from January 2010 to October 2020 at a tertiary care center.

Methods: Hypertensive phase was defined as intraocular pressure (IOP) >21 mmHg occurring at 2 consecutive visits in the first 90 days after the date of surgery for Ahmed Glaucoma Valve (AGV) or in the first 90 days after tube opening for Baerveldt Glaucoma Implant (BGI). Generalized estimating equations and Fisher exact tests were used to evaluate risk factors for HP and risk factors for failure of GDD surgery after occurrence of a HP.

Main outcome measures: Incidence and risk factors for HP. Overall surgical success rates, defined as the absence of failure criteria: IOP >21 mmHg, ≤5 mmHg, or <20% reduction below baseline IOP after 3 months for 2 consecutive visits, with or without adjunctive ocular hypotensive therapy; additional glaucoma surgery; or loss of light perception.

Results: Among 419 eyes of 360 patients that underwent GDD implantation, 42 (10.0%) eyes developed HP. Onset of HP was 20.8 ± 10.5 days after AGV and 11.7 ± 20.3 days from the date of tube opening after BGI. Mean IOP during HP was 26.5 ± 3.2 mmHg with peak IOP of 30.0 ± 5.9 mmHg. Median follow-up duration was 21.5 months after onset of HP. Younger age and neovascular glaucoma were significant risk factors for HP occurrence in a multivariable model. Resolution of HP occurred in 32 eyes (76.2%) after a mean duration of 48.0 ± 53.0 days. Additional surgery with a second GDD or cyclophotocoagulation was performed for 12 eyes (28.6%). The overall success rate among eyes with a HP was 52.6% at 2 years, which was significantly lower than that observed among control eyes that did not experience HP (76.3%), P < 0.01.

Conclusions: The incidence of HP was 10.0%. Younger age and neovascular glaucoma were significant risk factors for HP in the multivariable model. The risk of surgical failure after HP is significantly higher compared to eyes that did not experience HP.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Glaucoma drainage device; Glaucoma tube shunt surgery; Hypertensive phase; Intraocular pressure spike; Uveitic glaucoma.