Comparison of minimally invasive glaucoma surgery with trabecular micro-bypass stent and microhook ab interno trabeculotomy performed in conjunction with cataract surgery

AIM: To evaluate the effectuality and safety of cataract surgery combined with either ab interno trabeculotomy by the microhook (μLOT) or a single iStent® trabecular bypass implantation (iStent) in eyes with cataract and mild-to-moderate glaucoma. METHODS: This study enrolled subjects with mild-to-moderate open angle glaucoma with visually significant cataract who used two or more ophthalmic antiglaucoma agents between 60 and 90y of age. Patients underwent cataract surgery cooperated with either implantation of an iStent (iStent-phaco) or excisional goniotomy with the μLOT (μLOT-phaco). Patients underwent μLOT-phaco in the eye with lower the mean deviation, according to the Humphrey field analyzer, while iStent-phaco was carried out on the other eye. Intraocular pressure (IOP) pre- and post-surgery, alterations in anterior chamber flare (ACF), and corneal endothelial cell density (ECD) were estimated. RESULTS: Twenty subjects were enrolled (mean age: 73.6±7.3y). The mean medicated preoperative IOP was 16.7 mm Hg in the μLOT and 16.2 mm Hg in the iStent eyes. The mean final IOP at 12mo was 13.6 mm Hg in the μLOT eyes and 13.6 mm Hg in the iStent eyes, representing a 17.8% and 17.2% reduction, respectively. The preoperative ACF in the μLOT eyes was 9.5 pc/ms and it returned to normal in 30d postoperatively, with a value of 11.4 pc/ms. In the iStent eyes, ACF was 9.6 pc/ms preoperatively and it returned to normal by 7d postoperatively (11.2 pc/ms at day 7), demonstrating that postoperative inflammation was less in the iStent eyes. The corneal ECD in both groups was not significantly decreased. CONCLUSION: In this study, iStent and μLOT are both effective through 12mo of follow-up. Safety is more favorable in the iStent eyes, based on early anterior chamber inflammation.