Comparison of 1-year effectiveness between phaco-microhook ab-interno trabeculotomy and phaco-iStent trabecular micro-bypass stent in primary open-angle glaucoma with low-teen intraocular pressure

Purpose To investigate the surgical effectiveness of combined cataract surgery with microhook ab-interno trabeculotomy (phaco-mu LOT) or iStent trabecular micro-bypass stent (phaco-iStent) in eyes with primary open-angle glaucoma (POAG) and preoperative intraocular pressure (IOP) controlled below 15 mmHg (low-teen IOP). Methods This retrospective cohort study included consecutive patients with POAG and low-teen IOP who underwent phaco-mu LOT or phaco-iStent as their initial glaucoma surgery and were followed up for 1 year postoperatively. Surgical failure was defined as the inability to achieve the following criteria twice in a row: (A) IOP of 6-15 mmHg with over 20% IOP reduction; (B) IOP of 6-12 mmHg with over 20% IOP reduction. Results A total of 75 eyes from 75 subjects were included, with 48 in the phaco-mu LOT group and 27 in the phaco-iStent group. The mean preoperative IOP and number of antiglaucoma medications were 13.1 +/- 2.1 mmHg and 3.4 +/- 0.9 in the phaco-mu LOT group, and 12.6 +/- 2.0 mmHg and 2.5 +/- 1.2 in the phaco-iStent group, respectively. The number of antiglaucoma medications was significantly reduced to 2.5 +/- 0.9 (phaco-mu LOT) and 2.0 +/- 1.1 (phaco-iStent) at 1-year postoperatively (all p < 0.05). For criteria A and B, the survival rates were significantly higher in the phaco-<mu>LOT group than in the phaco-iStent group (all p < 0.01). Conclusion Both phaco-<mu>LOT and phaco-iStent hold promise in reducing the need for antiglaucoma medications in POAG eyes with low-teen IOP. Phaco-mu LOT may be more effective than phaco-iStent in controlling IOP.