Causes of Immediate and Early IOP Spikes After Circumferential Gonioscopy-Assisted Transluminal Trabeculotomy Using ASOCT

PURPOSE: To report the early postoperative causes of intraocular pressure (IOP) spikes after complete circumferential gonioscopy-assisted transluminal trabeculotomy (GATT) using anterior segment optical coherence tomography (ASOCT). METHODS: This was retrospective interventional case series of patients who underwent circumferential GATT by a single surgeon (APR) from 2021 to 2022 at a tertiary eye care in East India and who developed IOP spikes at 1 day-2 weeks (immediate) or early (>2 weeks–2 months) after GATT. The intraocular pressure (IOP), glaucoma medications, and angle evaluation by ASOCT at 1 week, and 1 month were compared between the two groups. RESULTS: Thirty-two eyes of 32 consecutive patients, aged 40±20.1 years (20 exfoliation glaucoma, 9 juvenile open-angle, and 3 developmental glaucoma), that developed IOP spikes between immediate (n=20) or early (n=12) IOP spikes after GATT, were included. Immediate postoperative spikes were seen in 20 eyes due to retained viscoelastic (n=8), hyphema (n=8) in uncontrolled hypertension, and peripheral anterior synechiae (PAS) (n=6) of which only one eye required medication at 2 months. Causes of immediate IOP spikes on ASOCT included an inverted/reattached trabecular shelf, iris strands in eyes with abnormal iris in developmental glaucoma, and PAS in 1–2 quadrants. Causes of early IOP spikes included PAS >3 quadrants (n=8), and hyperreflective fibrotic tissue over TM (n=4) with 50% requiring medications at 2 months. The ASOCT features predicting the need for medications were PAS >3 quadrants (OR=8.4[2.2–14.3], p=0.03) and fibrotic TM closure (OR=5.4, [3.6–10.2], p=0.003). One eye with macrohyphema 3 days after surgery owing to uncontrolled hypertension (owing to the stoppage of medicines), required additional incisional trabeculectomy within 1 month of surgery. CONCLUSION: Immediate IOP spikes are mostly self-resolving as opposed to early IOP spikes >2 weeks that require medications after GATT. Gonioscopic PAS >3 quadrants, and fibrotic TM closure were the main identifiable ASOCT causes predicting the need for medications after GATT.