TonoVet Plus®: Higher reliability and repeatability compared with Tono‐Pen XL™ and TonoVet® in rabbits

Abstract

Objective To evaluate the accuracy and repeatability of the Tono‐Pen XL™, TonoVet® and TonoVet Plus® tonometers by manometric evaluation, and to establish adjustment equations for intraocular pressure (IOP) estimates in rabbits. Animal Studied Rabbits. Procedures A postmortem study was conducted on seven rabbit eyes to verify the correlation between manometry and tonometry with an artificial incremental increase in IOP from 5 and 60 mmHg. A clinical study was conducted to evaluate accuracy and to establish reference values for the species, with measurement of IOP in 17 animals, for 2 consecutive days, with the same tonometers and calibrations used in the postmortem evaluations. Results There were strong linear trends for all evaluated tonometers. In the in‐vivo evaluation, the mean IOP values were: 14.23 ± 1.75 (Tono‐Pen XL™); 13.89 ± 2.07 (TonoVet® calibration mode ‘d’); 8.88 ± 1.24 (TonoVet calibration mode ‘p’); 18.59 ± 1.94 (Tonovet Plus®). There was a significant difference in the two evaluation times for the two TonoVet® calibration modes. The adjustment equations generated from the manometry for the evaluated tonometers were: Y = 0.2570X + 2.219 (Tono‐Pen XL™), Y = 0.2289X + 2.389 (TonoVet® ‘d’), Y = 0.4043X + 4.062 (TonoVet® ‘p’), Y = 0.1233X + 0.3644 (TonoVet Plus®) (X is device‐estimated IOP). Conclusions All evaluated tonometers were well correlated with the manometry, with an underestimation of IOP by all devices. Applying adjustment formulas may compensate for systematic errors. TonoVet Plus® was well tolerated, and showed better repeatability and reliability in successive evaluations.

Determination of intraocular pressure and Schirmer tear test and the comparison between the applanation tonometer (Tono‐Pen AVIA®) and the rebound tonometer (TonoVet Plus®) in mini lionhead rabbits

“…The determination of ophthalmic parameters, including IOP and tear production, are fundamental for the evaluation and monitoring of ocular diseases. The average values of IOP were measured with different tonometers, and the tear production was determined in different domestic and wild species, 9,[25][26][27][28][29] including New Zealand 6,12,13,15,16,18,21,[30][31][32][33] and Dutch Belted 34 rabbits. It is known that the physiological values of IOP and tear production vary considerably according to the methodology or tonometer used for measurement, as well as according to the species or even breed evaluated, 6,35 which makes the extrapolation of these parameters risky and imprecise.…”

Comparison of the TONOVET Plus®, TonoVet®, and Tono‐Pen Vet™ tonometers in normal cats and cats with glaucoma

“…In addition, the TVP has a larger display screen and requires only one push of a button to acquire the 6 consecutive measurements needed to obtain each IOP value. A few studies validating use of the TVP in dogs 17,34 and rabbits, 23,35 have reported that IOPs obtained with the TVP correlate well with manometry in these species, particularly in the clinically relevant range of 5–50 mmHg 17,23 …”

“…In addition, the TVP has a larger display screen and requires only one push of a button to acquire the 6 consecutive measurements needed to obtain each IOP value. A few studies validating use of the TVP in dogs 17,34 and rabbits, 23,35 have reported that IOPs obtained with the TVP correlate well with manometry in these species, particularly in the clinically relevant range of 5-50 mmHg. 17,23 The objective of this study was to validate IOP measurements obtained with the TVP rebound tonometer in normal cats and cats with glaucoma and compare the accuracy and precision of the values to those obtained by the widely used TV01 and TP.…”

Comparing the intraocular pressure values obtained with a rebound tonometer (TONOVET Plus) and an indentation tonometer (IOPvet) in dogs with and without ocular disease

“…6,7 Currently, electronic applanation and rebound devices (including iCare TONOVET and TONOVET Plus [TVP] and the Reichert Tono-Pen and Tono-Vera) are the most commonly used devices, and their accuracy has been studied extensively in dogs and other species. [8][9][10][11][12][13][14] These devices remain the best way to assess IOP, but they may be cost-prohibitive for some veterinarians.…”