Hydrus Versus iStent as Standalone Treatment for OAG
Ophthalmology, January 2020
Ahmed et al. hypothesized that a single Hydrus microstent would result in lower intraocular pressure (IOP) and reduced need for glaucoma medication in patients with open-angle glaucoma (OAG) compared to a pair of iStent devices. They found that the Hydrus resulted in a higher rate of surgical success and less need for glaucoma medication. The safety profiles of the two devices were similar.
For this prospective randomized study, the researchers included 152 patients (152 eyes) who were between 45 and 84 years old. All participants had OAG, a Shaffer angle of grade III or IV, best-corrected visual acuity (BCVA) of 20/30 or better, and IOP of 23 to 39 mm Hg after washout of hypotensive medications.
Study eyes were assigned randomly (1:1) to undergo standalone microinvasive glaucoma surgery (MIGS) consisting of one Hydrus or two iStents. Follow-up exams were performed on day 1, week 1, and months 1, 3, 6, and 12 following surgery. Outcomes of interest were between- and within-group differences in IOP and number of glaucoma medications at 12 months. Complete surgical success was defined as freedom from repeat glaucoma surgery, IOP ≤18 mm Hg, and no need for glaucoma medication. Safety measures included frequency of surgical complications, changes in VA, abnormal slit-lamp findings, and adverse events. The study groups were well matched in terms of baseline demographics, glaucoma status, medication use, and baseline IOP.
Twelve months of follow-up was completed by 148 patients (97.4%). At this point, the complete success rate was better for the Hydrus device compared to two iStents (30.1% vs. 9.3%; p < .001). The Hydrus also was associated with reduced need for glaucoma medication (p = .004); more Hydrus subjects were completely free of such medication by month 12 (p = .0057). Secondary glaucoma surgery was required for two eyes in the iStent group (3.9%) and none in the Hydrus group. Two eyes treated with Hydrus and one treated with iStent had BCVA loss of 2 lines or more.
The authors acknowledged the limitations of unmasked postoperative examinations but conclude that these findings suggest that trabecular MIGS devices may play an important role in managing IOP and reducing the need for hypotensive medication.
The original article can be found here.