Validation of the EYEMATE-SC Suprachoroidal Pressure Transducer for Telemetric Measurement of Intraocular Pressure in Normal Ex Vivo Canine and Equine Globes-Preliminary Results.

Abstract

Objective: To determine the accuracy of the EYEMATE-SC suprachoroidal tracer for telemetric tonometry in canine and equine globes.

Procedures: The EYEMATE-SC sensor (7.8 mm × 3.8 mm × 1 mm) was implanted in the suprachoroidal space of four freshly enucleated normal canine and two normal equine eyes. The anterior chambers were cannulated and connected to a reservoir of Plasma-Lyte A and a manometer. Starting at a manometric IOP of 5 mmHg, the pressure was progressively increased to 80 mmHg by raising the reservoir. At each setpoint (5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, and 80 mmHg), triplicate telemetric measurements were taken with the EYEMATE-SC using a portable reading device for telemetric pressure transmission via a radiofrequency band. These measurements were compared to manometric pressure by linear regression analysis.

Results: A strong positive linear regression was observed between EYEMATE-SC and manometry IOPs in both canine and equine eyes (canine: R² = 0.99; equine: R² = 0.99). The EYEMATE-SC was unable to measure pressures > 70 mmHg in either species.

Conclusions: Measuring canine and equine IOPs from the suprachoroidal space using the EYEMATE-SC provided accurate results over an extensive range of pressures in ex vivo globes. This telemetric sensor could assist with long-term, frequent tonometry by pet owners and clinicians following in vivo testing. Although the sensor could not detect pressures above 70 mmHg, this flaw was not considered clinically relevant.