Repeatability, reproducibility, and agreement of three tonometers for measuring intraocular pressure in rabbits

Abstract

The aim of this study was to evaluate repeatability, reproducibility, and agreement of three commonly used tonometers in animal research (TonoLab, TonoVet, and TonoPEN AVIA) in a cohort of 24 rabbits. Additionally, the impact of sedation on IOP was investigated in 21 New Zealand White rabbits with the TonoVet tonometer. Repeatability was determined using the coefficient of variation (CoV) for two observers. For the TonoLab (6.55%) and TonoVet (6.38%) the CoV was lower than for the TonoPEN AVIA (10.88%). The reproducibility was highest for the TonoVet (0.2 ± 3.3 mmHg), followed by the TonoLab (0 ± 12.89 mmHg) and lowest for the TonoPEN AVIA (− 1.48 ± 10.3 mmHg). The TonoLab and TonoVet showed the highest agreement (r = 0.85, R2 = 0.73). After sedation, a significant IOP reduction (often > 25%) was observed. Our results show that among the three tonometers tested, the TonoVet tonometer is best for use in rabbits while the TonoLab should be avoided. The impact of sedation on IOP was substantial and should be taken into account during experimentation.

Wound Healing Response After Bleb-Forming Glaucoma Surgery With a SIBS Microshunt in Rabbits

“…IOP deviations are often small within this type of animal model, as normotensive animals without glaucoma are used. 29 , 30 …”

Validation of a novel rebound tonometer (Tono‐Vera® Vet) in normal ex vivo rabbit eyes

“…Acquiring intraocular pressures (IOP) by tonometry is an important part of comprehensive ophthalmic examination in a research setting. Prior studies have investigated the use of various tonometers such as the TonoVet, Tonolab, TonoVet Plus, Perkins applanation tonometer, TonoPen Avia, TonoPen, TonoPen XL, and TAO1 in rabbits both in vivo and ex vivo 4–11 . The Reichert Tono‐Vera® Vet is a tonometer that was released for commercial use in January 2021.…”

“…Prior studies have investigated the use of various tonometers such as the TonoVet, Tonolab, TonoVet Plus, Perkins applanation tonometer, TonoPen Avia, TonoPen, TonoPen XL, and TAO1 in rabbits both in vivo and ex vivo. [4][5][6][7][8][9][10][11] The Reichert Tono-Vera® Vet is a tonometer that was released for commercial use in January 2021. This rebound tonometer has four different species-specific settings for dogs, cats, horses, and rabbits.…”

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

“…6 Research comparing various models of tonometers has shown that different IOP values are obtained depending on the equipment used. [7][8][9][10][11] Although reference values for tear production and IPO have been described for some breeds of rabbits in numerous scientific articles, the results vary greatly. Normal values for tear production have been described in New Zealand, [12][13][14] English Angora, and Mini Holstein 15 rabbits.…”

“…Likewise, IOP reference values and comparisons between values obtained by different tonometers were established for New Zealand and Dutch Belted rabbits. 10,11,[16][17][18][19][20][21] With the growing popularity of pet rabbits, the determination of basic ophthalmic parameters becomes essential, since the physiological parameters of a given species or breed are fundamental for the diagnosis and monitoring of their ocular diseases. 6,22 This determination becomes even more important in rabbits, which have a circadian rhythm that is different from other species of domestic animals and show different IOP throughout the day.…”