Abstract
Purpose :
Diplopia is a known complication of glaucoma drainage device implantations. The aim of this study was to quantify any diplopia and motility changes after the surgical insertion of a Baerveldt glaucoma implant (BGI).
Methods :
Fifty-nine Glaucoma patients with no history of intra- or extraocular surgery were enrolled in a prospective cohort study at the Rotterdam Eye Hospital, The Netherlands. Exclusion criteria consisted of a history of strabismus or best corrected visual acuity <20/200. Before surgery and one year post-operatively, an orthoptist interviewed patients about the presence of any diplopia and quantified their ocular alignment (at near fixation and at distance), fusion range, and monocular ductions.
Results :
One year after the BGI, 16 patients (27%) reported post-surgical diplopia, of whom 7 patients (12%) experienced intermittent diplopia and 2 patients (3%) persistent diplopia, in the primary position and/or during reading. At near fixation, the ocular alignment changed in the horizontal direction in 14 patients (24%) and in the vertical direction in 2 patients (3%) (figure 1a). At distance, 21 patients (36%) had horizontal deviations and 5 patients (8%) had vertical deviations. The binocular fusion range diminished in 47% of the patients and increased in 34% of the patients (figure 1b). Five patients (5%) showed no change in fusion range and in 7 patients (11%) it was not possible to measure the fusion range. Monocular ductions changed in 22% of cases; especially limited were elevation (17%) and abduction movements (8%). With logistic regression, a statistically significant association was found between ocular alignment changes and diplopia (p<0.022, odds ratio = 0.76).
Conclusions :
Our results confirm that in patients with a BGI, a change in motility may occur, which may cause diplopia. The BGI obstructs eye movements mostly in gaze directions towards the location of the implant, temporo-superior. There is a higher risk that patients with increased ocular alignment changes will develop diplopia. Patients need to be aware of this risk, associated with BGI surgery. Further efforts are now required to determine the exact mechanism underlying the cause of diplopia in patients with a BGI.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.