Rates of Diplopia in Ahmed FP7, Baerveldt 250, and 350 Glaucoma Patients Compared With Medical Controls.

PRECIS

Diplopia was present in ~20% of patients with Ahmed FP7 (FP7) or Baerveldt 350 (B350), compared with 5% to 6% in those with Baerveldt 250 (B250) or controls, suggesting risk of diplopia should be included in preoperative counseling.

PURPOSE

The purpose of this study was to examine the prevalence of diplopia and strabismus in patients with B250, B350, or FP7 glaucoma drainage devices (GDD).

MATERIALS AND METHODS

In this cohort study, glaucoma patients 18 years and above who had received, or would be receiving, a B250, B350, or FP7 GDD, and medically treated controls were consecutively enrolled from August 8, 2017, through July 31, 2019. The Diplopia Questionnaire was administered ≥30 days postoperatively, and upon enrollment to the controls. All diplopic patients underwent orthoptic measurements, which were reviewed by a strabismus specialist. Patients with GDDs in quadrants other than superotemporal, multiple GDDs, or scleral buckles were excluded. Bonferroni correction was applied for pairwise comparisons.

RESULTS

Diplopia was reported in 23/129 (17.8%) GDD patients and 5/99 (5.1%) control patients (P=0.003): 8/35 (22.9%) FP7, 2/32 (6.3%) B250, and 13/62 (21.0%) B350, with significant differences between FP7 versus controls (P=0.014) and B350 versus controls (P=0.011). Diplopia was attributable to GDD in 2 FP7 (5.9%, 95% confidence interval: 0.7-19.2), 0 B250, and 4 B350 (6.5%, 95% confidence interval: 1.7-15.2) patients, without significant differences between the GDDs.

CONCLUSIONS

Patients with the larger (B350) or the higher profile plate (FP7) GDDs were more likely to experience diplopia than controls, and diplopia was attributable to the GDD in ~6% of patients with either a FP7 or a B350 GDD. Since diplopia can affect patients' quality of life, preoperative counseling for GDD surgery, particularly B350 and FP7, should include a discussion of the risk of diplopia.