Comparative evaluation of iStent versus iStent inject W combined with phacoemulsification in open angle glaucoma.

ABSTRACT

PURPOSE: The study aimed to compare the 12-month post-operative outcomes of iStent and iStent inject W (inject W), and the factors associated with their success in open-angle glaucoma. METHODS: This single-center, retrospective comparative case series evaluated the medical records of patients who underwent iStent (comprising 1 stent) or inject W (comprising 2 stents) implantation with cataract surgery for primary open-angle glaucoma and normal tension glaucoma between January 2019 and March 2022. The 12-month post-operative efficacy outcomes included intraocular pressure (IOP), glaucoma medications, and survival analysis of the probability of success. "Failure" was defined as any of the following conditions compared to baseline 1) IOP elevation, 2) increased glaucoma medication, or 3) IOP decline not exceeding 20% when glaucoma medication scores were comparable, and 4) need for additional glaucoma surgery. The safety outcomes included intra- and post-operative adverse events and changes in the best-corrected visual acuity and visual field. RESULTS: The study comprised 55 eyes in the iStent and 105 in the inject W groups. At 12 months, treatment success was achieved in 66.0% of iStent and 78.4% of inject W eyes. The mean IOP was lower, and the percent reduction from baseline was equal in iStent-treated eyes (8.0% reduction, 14.8 mmHg to 13.7 mmHg, P<0.01) and inject W-treated eyes (11.9% reduction, 15.0 mmHg to 13.8 mmHg, P<0.01) (between-group comparison, P = 0.23). The mean medication burden decreased significantly from 2.5 to 1.1 for iStent (55.0% reduction, P<0.01) and 2.9 to 1.7 for iStent inject (46.8% reduction, P<0.01), with no significant differences between the two groups (P = 0.17). Both devices exhibited excellent safety. CONCLUSIONS: Both devices significantly reduced IOP and glaucoma medication 12 months post-operatively. The outcome measures did not differ significantly between the two groups, and lower baseline IOP was predictive of surgical failure.