Tonographic Outflow Facility and Intraocular Pressure After Standalone OMNI Surgery

The OMNI surgical device produces a statistically significant reduction in intraocular pressure and a significant increase in tonographic outflow facility at 3 months, which is found to be nonsignificant at 12 months for both parameters.

OMNI is a minimally invasive glaucoma surgical device designed to address all 3 points of conventional outflow resistance (juxtacanalicular trabecular meshwork, inner wall of Schlemm canal, and resistance distal to the canal). This study assessed its effects on intraocular pressure (IOP) and on changes in tonographic outflow facility (TOF) after medication washout.

Thirty eyes of 30 patients with uncontrolled open angle glaucoma or ocular hypertension were prospectively recruited. Each patient underwent a 4-week washout baseline IOP measurement and TOF recording via digital Schiøtz tonography. Patients received standalone 360-degree canaloplasty and 160 to 180-degree trabeculotomy. Measurements were repeated at 3 and 12 months post-treatment (with further washout).

At 3 months, a mean IOP reduction by 3.26 mm Hg from baseline (27.25±9.0 vs. 23.99±10.84 mm Hg, P =0.03) was achieved, with a statistically significant increase in TOF (0.068±0.045 vs. 0.14±0.090 µL/min/mm Hg, P =0.0002). At 12 months, a mean IOP reduction of 1.57 mm Hg was achieved (27.25±9.0 vs. 25.68±12.04 mm Hg, P =0.6) with no significant TOF change (0.068±0.045 vs. 0.10±0.09 µL/min/mm Hg, P =0.07). Thirty-two percent experienced a >20% IOP reduction (n=9), with 25% achieving an IOP <18 mm Hg (n=7) at 12 months.

This is the first study to assess the standalone effect of the OMNI device on IOP and TOF changes pre- and post-treatment. While an IOP reduction and an increase in TOF were noted at 3 months, these were not statistically significant at 12 months.