Binocular disturbance after glaucoma drainage device implantation

Abstract

Binocular vision disturbance is a well-described complication of glaucoma drainage device (GDD) implantation. The pathophysiology is not well-understood, but may involve bulk effects from the implant and surrounding bleb, as well as modulation of muscle function due to surgical trauma and post-operative inflammation, resulting in a combined resection/posterior fixation effect. Retrospective studies have found the risks of motility disorder and diplopia vary widely, estimated to be 56%-86% and 57%-75%, respectively. More recently, cross-sectional studies and prospective trials estimate post-GDD incidence to be approximately 1%-44%, with the incidence in newer generation of implants designed to limit bleb size likely lower at 1%-5%. Suggested methods of management strategies include prismatic spectacles, monocular occlusion, extreme monovision, and strabismus surgery.

Keywords: Glaucoma, Drainage, Implant, Device, Diplopia, Motility, Binocular, Disturbance, Strabismus

Core tip: The reported incidence of binocular disturbance after glaucoma drainage device (GDD) implantation is variable due to inconsistent study designs, disturbance definition and lack of pre-operative baseline evaluations. The incidence of motility disorder is likely higher than persistent diplopia, as some glaucoma patients requiring GDD are functionally monocular. The mechanism or disturbance is not well-understood, but the bulk of implant/bleb, changes in muscle length, tension and strength may result in a combined resection/posterior-fixation effect. Post-GDD diplopia may resolve spontaneously in some instances, while the intractable cases are usually managed with prismatic spectacles.