Abstract
Purpose :
Baerveldt drainage device Implantation (BGI) and trabeculectomy (TE) are both surgical procedures for lowering the intraocular pressure in the management of glaucoma. Diplopia may be a serious complication of BGI. The purpose of this study is to quantify any diplopia and motility changes after glaucoma surgery by BGI or TE.
Methods :
We analyzed 51 patients with a BGI and 52 patients with a TE from a prospective cohort study at the Rotterdam Eye Hospital, the Netherlands. To quantify any diplopia, we asked patients about the presence of diplopia 1 year after surgery. When diplopia was present, the diplopia was defined as either gaze-evoked diplopia or diplopia in primary position and/or while reading. To quantify any ocular motility changes, we measured the ductions in 8 gaze directions with a synoptophore, both before surgery and 1 year postoperatively. We evaluated the patients’ ocular alignment with the patient fixating at 30 cm distance with the alternate prism cover test and with the patient fixating at distance with the synoptophore. The latter was also used to measure the fusion range.
Results :
Significantly more patients experienced diplopia in the BGI group than in the TE group (p<0.001, Fisher’s exact test). In the BGI group, 6 patients experienced gaze-evoked diplopia and 8 patients had diplopia in primary position and/or while reading. By contrast, only 1 TE patient experienced diplopia. The duction restrictions of the operated eye in the BGI group, compared to the TE group, were statistically significant in abduction (p = 0.02; Man Whitney U-test), in elevation (p = 0.002) and in elevation in 25oabduction (p = 0.005). Not surprisingly, all 6 BGI patients with gaze-evoked diplopia had a duction reduction (fig. 1). 6 of the 8 BGI patients with diplopia in primary position and/or while reading had an ocular alignment outside their fusion range (fig. 2). The fusion range was not sufficient to correct the deviation in their ocular alignment, which might explain their diplopia.
Conclusions :
BGI surgery was significantly associated with diplopia and reduced duction. The duction reduction was mostly present in gaze directions towards the location of the implant, superotemporally, which can lead to experiencing diplopia. Further research is now required to determine the underlying cause of diplopia in patients with a BGI. Understanding the mechanism may lead to novel methods to reduce the diplopia risk after BGI.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.