Binocular disturbances following glaucoma drainage device surgery

To estimate the risk of developing strabismus and/or diplopia following glaucoma drainage device implantation in patients with glaucoma.

A retrospective clinical cohort study.

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.

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).

GDD implantation in glaucoma patients was associated with a significantly increased risk of developing strabismus and diplopia.