Binocular disturbances following glaucoma drainage device surgery.

OBJECTIVE: To estimate the risk of developing strabismus and/or diplopia following glaucoma drainage device implantation in patients with glaucoma. DESIGN: A retrospective clinical cohort study. METHODS: We utilized deidentified electronic medical records, identifying adults (aged ≥18 years) diagnosed with glaucoma. Two cohorts were compared: patients who underwent glaucoma drainage device (GDD) implantation and those who did not. Propensity score matching (PSM) (1:1) was applied to control for demographic, systemic, and ocular comorbidities. The primary outcomes were new diagnoses of strabismus or diplopia at 1- and 5-year follow-ups. Multivariable Cox proportional hazard models estimated adjusted hazard ratios (aHRs) and CIs. RESULTS: Prior to PSM, 10,192 patients underwent GDD implantation, and 139,045 did not. After matching, each cohort included 9614 patients. At 1 and 5 years, strabismus was more frequent in the GDD group (1.4% vs 0.52%, and 2.54% vs 1.16%), and diplopia (2.03% vs 0.49%, and 3.01% vs 1.26%; all p < .001). Cox proportional hazards model showed an increased hazard of strabismus (aHR: 1.65 [95% CI: 1.42-1.92] at 1 year; 1.61 [1.43-1.81] at 5 years) and diplopia (aHR: 2.08 [1.81-2.38] at 1 year; 1.61 [1.44-1.80] at 5 years) in the GDD group. The likelihood of strabismus surgery did not differ significantly between groups at 1 year (aHR: 0.99 [95% CI: 0.56-1.70]; p = .98) but was significantly increased at 5 years (aHR: 1.47 [95% CI: 1.05-2.06]; p = 0.024). CONCLUSIONS: GDD implantation in glaucoma patients was associated with a significantly increased risk of developing strabismus and diplopia.