Risk factors for layered hyphema following goniotomy or trabecular bypass stent placement combined with phacoemulsification

Abstract

Purpose : The utilization of angle-based minimally invasive glaucoma surgery has increased significantly over the last decade by glaucoma and non-glaucoma specialists. The purpose of this study was to investigate risk factors for the development of a layered hyphema following phacoemulsification combined with goniotomy (PG) or trabecular bypass stent (PTBS).

Methods : Patient data was obtained using a retrospective chart review from consecutive adult patients undergoing either PG or PTBS at the West Virginia University Eye Institute between May 1^st 2015 and February 7^th 2023. Pre-operative and post-operative variables having a possible relationship to post-operative hyphema were collected based on existing evidence in the literature and/or clinical domain knowledge. These characteristics included age, race, glaucoma severity, glaucoma type, pre-operative IOP, pre-operative IOP lowering medications, systemic antithrombotic medications, body mass index (BMI), surgery type (e.g., PG or PTBS) and post-operative day one IOP. Given the high frequency of microhyphema (anterior chamber red blood cells without layering) following angle-based MIGS surgeries, hyphema was defined as layered red blood cells within the anterior chamber at post-operative day one. Separate univariate general estimating equation (GEE) analyses were conducted to identify predictors of hyphema experienced by patients on post-operative day one after MIGS. Variables significant at the univariate level were then entered simultaneously into a multivariate model to predict hyphema.

Results : Data included 457 eyes from 310 patients. The overall layered hyphema rate was 10.7% across all surgeries with 13.0% and 1.10% in the PG and PTBS eye groups, respectively. Table 1 shows the baseline features of the cohort. Table 2 presents univariate GEE analyses for all collected predictors of hyphema. When the variables significant in the univariate analysis were entered into the GEE model simultaneously, only surgery type remained a significant predictor (B=2.44, SE=1.02, p-0.02) of post-operative day one layered hyphema.

Conclusions : The risk of post-operative day one hyphema is higher with PG over PTBS surgeries. The use of anti-thrombotics and other ocular and systemic variables were not significant predictors of hyphema in this cohort.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.