Abstract
The Hydrus Microstent (HM) and iStent inject W are two widely used trans-trabecular bypass devices and can be combined with phacoemulsification for glaucoma patients undergoing cataract surgery. AIM: To compare the efficacy and safety of the HM with triple iStent inject W devices (TiSW) devices combined with phacoemulsification in a real-world setting over 3 years of follow-up. METHODS: A prospective, consecutive, quasi-experimental, longitudinal study was conducted on open-angle glaucoma patients at a subspecialty cataract and glaucoma private practice in Brisbane, Australia. Outcomes included yearly changes from preoperative values in mean IOP and mean number of glaucoma medications; proportional shifts across IOP and number of glaucoma medication categories at preoperative and yearly time points, and hazard ratio for time to failure based on the American Academy of Ophthalmology combined minimally invasive glaucoma surgery criteria. Multi-level mixed effects regression modelling with inverse probability of treatment weighting was used to estimate the treatment effect while accounting for repeated measurements, clustering, confounding, and imbalances in baseline covariates. RESULTS: Of the 105 cases, 56 (53.3%) phacoemulsification cases were combined with the HM and 49 (46.7%) were combined with the TiSW. At 3 years, the mean IOP reduction in the HM was 2.6 mmHg (from 15.1 to 12.5 mmHg), while the TiSW showed a reduction of 2.0 mmHg (from 15.2 to 13.2 mmHg). No significant between-group differences in estimated changes in mean IOP from preoperative values were found at years 1, 2, and 3 (all Holm adjusted p = 1.00). Significant reductions in the estimated mean number of medications were observed in both groups at 3 years. The changes in mean number of medications from preoperative values at yearly timepoints were not statistically significant between groups (all Holm adjusted p = 1.00). The 3-year reduction was 1.3 medications in the HM (from a total of 2.3 to 1.0) and 1.4 medications in the TiSW (from a total of 2.2 to 0.8), resulting in a difference of 0.1 (95% CI: -0.6, 0.8). The proportions of eyes that were medication-free at 3 years were 54.3% in the HM group and 61.2% in the TiSW group. The intraoperative safety of the HM and TiSW was good, with no significant complications. CONCLUSION: This study has shown that both HM and TiSW provide effective IOP reduction and medication reduction in glaucoma patients undergoing combined cataract surgery at up to 3 years follow-up. Both devices were well-tolerated. Surgeon preference may guide device selection, with specific considerations for patients such as extremes of ocular size or anticoagulation therapy.