Hydrus microstent compared to selective laser trabeculoplasty in primary open angle glaucoma: One year results

Background: To compare the reduction of intraocular pressure (IOP) and glaucoma medications following selective laser trabeculoplasty (SLT) versus stand-alone placement of the Hydrus microstent, a microinvasive glaucoma surgery device. Design: Prospective interventional case-series. University practice. Participants: Fifty six eyes (56 patients) with uncontrolled primary open-angle glaucoma. Methods: Patients received either SLT (n=25) or Hydrus implantation (n=31) in two centres. Patients were evaluated at baseline and 1, 7days, 1, 3, 6 and 12months after surgery. Main Outcome Measures: Intraocular pressure and number of glaucoma medications variations inter-groups and intra-groups. Results: There were no significant differences at baseline between groups, but the mean deviation was worse in the Hydrus group (-8.43±6.84dB, confidence limits (CL)-2.8/-3.3 vs.-3.04±0.65dB, CL-6/-10.8; P<0.001). After 12months, there was a significant decrease in IOP and medications in the Hydrus group compared with baseline values. In the SLT group, only the decrease in IOP was significant. There was 3-fold greater reduction in medication use in the Hydrus group compared with SLT (-1.4±0.97 vs.-0.5±1.05, P=0.001). 47% of patients were medication free at 12months in the Hydrus group (4% in the SLT group). No complications were recorded in the SLT group. In the Hydrus group, three patients experienced a temporary reduction of visual acuity post-operatively, and two patients had post-operative IOP spikes that resolved within one week. Conclusions: Both SLT and Hydrus implantation reduced IOP without serious adverse events. Hydrus implantation led to a significant and further reduction in medication dependence at 12months. © 2016 Royal Australian and New Zealand College of Ophthalmologists