Validation of the eyeTelemed IOPvet indentation tonometer for use in dogs

Abstract

AbstractObjectiveTo assess the accuracy of canine intraocular pressure (IOP) estimates from the eyeTelemed IOPvet indentation tonometer.Animals StudiedPart 1 included 54 eyes from 28 Beagle dogs—23 ADAMTS10‐mutants with open‐angle glaucoma and 5 normals. Part 2 involved five normal canine ex vivo globes.ProcedurePart 1 (in vivo) compared IOPvet estimates in normal and glaucomatous dogs to Reichert Tono‐Vera® Vet rebound tonometry. The three IOPvet estimates were green (normal; <20 mmHg, according to the manufacturer), yellow (elevated; 20–30 mmHg), and red (high; >30 mmHg). In Part 2 (ex vivo), the pressure inside freshly enucleated normal canine eyes was progressively increased from 5 to 80 mmHg and compared to IOPvet estimates. Descriptive statistics compared IOPvet estimates to rebound tonometry and direct manometry, with the threshold from normal to glaucoma set at 30 mmHg.ResultsIn Part 1 (in vivo), normal pressures (≤30 mmHg) were mainly identified correctly as green or yellow—110 of 111 estimates, corresponding to a specificity of 99%. Only 16 of 125 affected estimates were correctly displayed in the >30‐mmHg range; the remaining 109 showed ≤30 mmHg, corresponding to a sensitivity of 13%. In Part 2 (ex vivo), all normal pressures were correctly estimated with green, but 64 of 88 manometric IOPs >30 mmHg were falsely estimated as 20–30 mmHg.ConclusionsThe IOPvet is inaccurate in estimating canine IOP with a low sensitivity at identifying dogs with IOP > 30 mmHg. Canine‐specific instrument revision is required to correctly identify elevated (yellow = 20–30 mmHg) and high (red >30 mmHg) IOPs.