Hemorrhagic Complications Following Trabecular Bypass Microstent Surgery in the Setting of Antithrombotic Therapy

Abstract

Précis: In this retrospective study, the use of chronic antithrombotic therapy (ATT) did not increase the risk of hemorrhagic complications after trabecular bypass microstent surgery and phacoemulsification. Stent type and female sex were associated with hyphema. Purpose: To report the incidence of hemorrhagic complications after trabecular bypass microstent surgery and phacoemulsification with and without (ATT). Methods: Retrospective case series on glaucoma patients on chronic ATT who underwent trabecular bypass microstent surgery (iStent, iStent inject, and Hydrus) combined with phacoemulsification between 2013 and 2019 with ≥3-month follow-up. The primary outcome measure was the incidence of hemorrhagic complications within a 3-month postoperative period. Generalized estimating equations were created to account for inter-eye correlation and logistic regression analysis was performed to identify factors predictive of hemorrhagic complications. Results: Of 333 patients (435 eyes), 161 patients (211 eyes) were on ATT and 172 patients (224 eyes) were not on ATT; both groups were similar in age and baseline ocular characteristics. The only hemorrhagic complication was hyphema, which occurred in 84 (19.3%) eyes (41 ATT, 43 non-ATT eyes; P = 1.00). Onset was at postoperative day 1 in 98.8% of eyes, with a duration of 1 week in 73.8% of eyes, without difference between ATT and non-ATT groups. Hyphema was most common with Hydrus microstent (36.4%) versus iStent (19.9%) and iStent inject (8.5%) (P = 0.003). In the multivariate model, the female sex was a predictor of hyphema [hazard ratio (HR) = 2.062; P = 0.009], iStent inject was protective against hyphema (HR = 0.379; P = 0.033), whereas Hydrus did not reach statistical significance (HR = 2.007; P = 0.081). Age, systemic comorbidities, ATT use, and baseline ocular characteristics were not significant predictors. Conclusions: Hemorrhagic complications after trabecular bypass microstent surgery were limited to transient hyphema and were not associated with chronic ATT use. Stent type and female sex were associated with hyphema.