Optimizing the sequential approach of combined phacoemulsification and gonioscopy-assisted transluminal trabeculotomy (GATT) in primary open-angle glaucoma.

Background: To evaluate the efficacy, safety and complication of different procedure sequence combining gonioscopy-assisted transluminal trabeculotomy (GATT) either before or after phacoemulsification for patient with primary open-angle glaucoma (POAG) and cataract.

Methods: This retrospective, clinic control study included 82 patients (82 eyes) with a diagnosis of POAG with cataract. The patients were divided into two groups: Phaco-GATT group underwent phacoemulsification followed by GATT and GATT-Phaco group underwent GATT followed by phacoemulsification. Intraocular pressure (IOP) changes, best-corrected visual acuity (BCVA), visual field Mean Deviation (MD) and antiglaucoma medication (AGM) were analyzed preoperatively and at postoperatively 1d, 1w, 1 m, 3 m, 6 m, and 12 m. Postoperative complications, including hyphema, IOP spikes, and suprachoroidal effusion, were closely reported.

Results: A total of 40 eyes were subjected to Phaco-GATT group, and 42 eyes were subjected to GATT-Phaco group. For all patients, significant IOP and AGM reduction and BCVA improvement were observed at each follow-up time points compare to preoperation (all P > 0.05). At 12 months, the visual field MD in the GATT-Phaco group was significantly improved than that in the Phaco-GATT group (P < 0.05). GATT-Phaco group appeared to have less AGM than those in Phaco-GATT group from postoperative 1 month to 12 months, though there was no significantly difference (all P > 0.05). At 12 months postoperatively, GATT-Phaco group demonstrated a slightly higher complete success rate of 76.2% and qualified success rates of 90.5% compare to Phaco-GATT (65.0% and 85.0%). Moreover, in the GATT-Phaco group, BCVA was significantly improved and macrohyphema (> 1 mm) was reduced compare to Phaco-GATT group at early stage. Additionally, no statistically significant differences were observed in IOP spike, descemet's membrane detachment, and supraciliary effusion between two groups at each time point.

Conclusions: This study demonstrates that combined phacoemulsification and GATT is a safe and effective treatment for POAG patients with cataract. Both surgical sequences are effective, however, initiating with GATT may provide more benefits compare phacoemulsification prior.