Structural reversal of disc cupping measured in Bruch’s membrane opening-based OCT morphometry after PRESERFLO microshunt implantation for glaucoma

Abstract

Purpose : To analyse the longitudinal change in Bruch’s membrane opening minimal rim width (BMO-MRW) and peripapillary retinal nerve fibre layer (pRNFL) thickness using optical coherence tomography (OCT) after implantation of a PRESERFLO microshunt for surgical glaucoma management in adult glaucoma patients.

Methods : Retrospective data analysis of 59 eyes of 59 participants undergoing implantation of a PRESERFLO microshunt between 2019 and 2022 at a tertiary center for glaucoma management. Surgical management included primary temporary occlusion of the glaucoma shunt to prevent early hypotony. Pre- and post-operative OCT examinations of the optic nerve head (ONH) and intraocular pressure (IOP) were assessed. Longitudinal change in morphometric spectral domain OCT parameters of the ONH was compared to change in IOP.

Results : BMO-MRW increased significantly between baseline (BL) and follow-up (FU) within the first three months after surgery (BL=171.15±66.80µm; FU=180.78±70.394µm; p=0.034). For the same postoperative period, mean preoperative IOP of 24.97±7.22mmHg was lowered after surgery to 12.53 ± 4.86 mmHg. Nine months after surgery (range, 7-12 months), there was no significant change in BMO-MRW compared to baseline (BL=202.43±89.93µm;FU=202.07±90.98µm; p=0.924), while mean IOP was 13.69 ± 4.46 mmHg. Peripapillary RNFL thickness was unchanged in follow up after three months (p>0.16) and significantly decreased in later follow-up (p=0.009).

Conclusions : PRESERFLO microshunt implantation with primary temporary occlusion leads to a significant transient increase inBMO-MRW known also as structural reversal of disc cupping (SRDC). The effect seems to be less pronounced and of shorter duration when compared to previous data after trabeculectomy with comparable pre- and postoperative IOP levels. The extend of SRDC may be associated with (sub-)clinical early hypotony after surgery.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.