Dynamics of structural reversal in Bruch's membrane opening-based morphometrics after glaucoma drainage device surgery.

Abstract

Structural reversal of disc cupping is a known phenomenon after trabeculectomy. The aim of this retrospective, longitudinal, cross-sectional analysis was to evaluate the postoperative dynamics of Bruch's membrane opening-based morphometrics of the optic nerve head following glaucoma drainage device surgery. Forty-three eyes, treated by glaucoma drainage device surgery, were included in the study. Individual changes in the spectral domain optic coherence tomography (SD-OCT) parameters Bruch's membrane opening minimum rim width (BMO-MRW), Bruch's membrane opening minimum rim area (BMO-MRA) and peripapillary retinal nerve fiber layer (RNFL) thickness as well as mean defect in 30-2 perimetry were analyzed. Changes were correlated to postoperative intraocular pressure levels over time. Available follow-up visits were aggregated and grouped into a short-term follow-up (20 to 180days after surgery), a midterm follow-up (181 to 360days after surgery) and a long-term follow-up (more than 360days after surgery). In short-term follow-up, BMO-MRW and BMO-MRA increased significantly (p <= 0.034). This increase correlated negatively with the intraocular pressure at the time of the follow-up (Pearson's rho = - 0.49; p = 0.039). From 6months after surgery on, there was no statistically significant change in BMO-MRW and BMO-MRA (p >=0.207). RNFL thickness and mean defect of 30-2 perimetry showed no significant changes after GDD implantation (p >=0.189). Lowering of intraocular pressure by glaucoma drainage device surgery leads to an increase of Bruch's membrane opening based parameters in the first 6months after surgery. These changes have to be taken into account when evaluating patients' longitudinal follow-up after glaucoma drainage device implantation.