Twelve-month data from an international feasibility study suggest that a laser-adjustable aqueous shunt may allow clinicians to modulate outflow resistance safely after implantation, offering a potential new approach to postoperative intraocular pressure (IOP) management. Results from the study of the Calibreye Titratable Glaucoma Therapy Surgical System, developed by Myra Vision, were presented during the poster session Thursday at the American Glaucoma Society’s annual meeting.
The Feasibility Clinical Evaluation of the Calibreye System was a prospective, multicenter, nonrandomized, open-label study that enrolled 42 patients with open-angle glaucoma at 4 clinical sites in India, Mexico, and Panama. Patients underwent unilateral implantation of the investigational shunt with mitomycin C. The device incorporates nitinol valves that can be reversibly opened or closed using a slit lamp-mounted green laser, allowing clinicians to adjust flow through microfluidic channels across 4 discrete resistance settings (Figures 1 and 2).
Figure 1. The Calibreye Titratable Glaucoma Therapy Surgical System. Images courtesy Myra Vision.
According to the poster’s lead author, Iqbal Ike K. Ahmed, MD, FRCSC, most postoperative adjustments occurred early. Among 82 resistance-lowering titrations, the median time to first and second adjustment was 3.5 and 12 days, respectively. At 12 months, 81% of implanted eyes were set at the device’s lowest resistance. Among 31 eyes with complete follow-up, mean IOP was 14.5±4.6 mmHg, representing a 35% reduction from a baseline of 22.7±4.1 mmHg on an average of 3.2±1.1 medications. Nearly all patients (93.5%) were medication free or using the same or fewer medications than at baseline.
Figure 2. Postoperative in-office titration using transcorneal laser.
Investigators reported that resistance was increased in 7 eyes, resulting in a mean IOP rise of 1.9±1.3 mmHg, demonstrating bidirectional control. No intraprocedural adverse events were reported across the study cohort, and no cases required bleb needling.
The authors concluded that the adjustable resistance mechanism produced IOP and medication reductions comparable to existing glaucoma drainage devices, while adding the ability to tailor outflow postoperatively. They noted that reversibility may help mitigate early hypotony and allow individualized pressure control over time, though longer-term follow-up is needed.
Myra Vision recently announced that the first patients have been enrolled in ADAPT, a US-based investigational study evaluating the Calibreye system. The trial follows FDA approval of an investigational device exemption in August 2025.
ADAPT is a prospective, multicenter, nonrandomized, open-label study that plans to enroll up to 70 patients with refractory glaucoma, with a primary effectiveness endpoint at 12 months. The study will further assess the safety and effectiveness of postoperative, clinician-directed outflow titration in a US population. GP