Abstract: Objective: The purpose of this study was to validate the use of the Reichert Tono-Vera® Vet tonometer rabbit setting in normal ex vivo rabbit eyes and to compare the rabbit setting to the dog, cat, and horse settings of this tonometer.
Procedure: Six freshly enucleated normal rabbit eyes were cannulated and connected to a fluid reservoir and physiologic monitor. Triplicate measurements were obtained with the four available settings: dog, cat, horse, and rabbit at various intraocular pressures (IOP) ranging from 5 to 80 mmHg. Bland-Altman analysis was utilized to determine bias and 95% limits of agreement for each setting.
Results: Linear regression equations for the dog, horse, cat, and rabbit settings were y = 0.8101x + 2.5058, y = 0.7594x - 3.4673, y = 0.6635x + 0.3021, and y = 0.8935x + 1.3295, respectively. All settings demonstrated strong positive linear trends (dog r 2 = 0.9644, horse r 2 = 0.9456, cat r 2 = 0.9309, and rabbit r 2 = 0.9558). Bland-Altman plots revealed that the average bias and 95% limits of agreement (mmHg) were -4.73, -12.65, -12.86 and -2.73 and (-15.31, 5.86), (-29.03, 3.74), (-25.67, -0.05), and (-12.21, 6.76) for the dog, horse, cat, and rabbit settings, respectively.
Conclusion: The Tono-Vera® Vet rabbit setting provided the most accurate and precise measurements compared with the other settings, but slightly underestimated actual IOP, especially as IOP was increased. This tonometer, using the rabbit setting, is likely to be appropriate for the estimation of IOP in rabbits with the appropriate correction formula applied.
(© 2023 American College of Veterinary Ophthalmologists.)
References: Zernii EY, Baksheeva VE, Iomdina EN, et al. Rabbit models of ocular diseases: new relevance for classical approaches. CNS Neurol Disord Drug Targets. 2016;15:267-291.
Fox RR, Crary DD, Babino EJ, Sheppard LB. Buphthalmia in rabbit - pleiotropic effects of (Bu) gene and a possible explanation of mode of gene action. J Hered. 1969;60:206-212.
Li WC, He B, Dai WB, Zhang Q, Liu YL. Evaluations of therapeutic efficacy of intravitreal injected polylactic-glycolic acid microspheres loaded with triamcinolone acetonide on a rabbit model of uveitis. Int Ophthalmol. 2014;34:465-476.
Pereira FQ, Bercht BS, Soares MG, da Mota MGB, Pigatto JAT. Comparison of a rebound and an applanation tonometer for measuring intraocular pressure in normal rabbits. Vet Ophthalmol. 2011;14:321-326.
Zhang H, Yang D, Ross CM, Wigg JP, Pandav S, Crowston JG. Validation of rebound tonometry for intraocular pressure measurement in the rabbit. Exp Eye Res. 2014;121:86-93.
Ma D, Chen CB, Liang JJ, Lu ZH, Chen HY, Zhang MZ. Repeatability, reproducibility and agreement of intraocular pressure measurement in rabbits by the TonoVet and Tono-pen. Sci Rep. 2016;6:19217.
Lobler M, Rehmer A, Guthoff R, Martin H, Sternberg K, StachsO O. Suitability and calibration of a rebound tonometer to measure IOP in rabbit and pig eyes. Vet Ophthalmol. 2011;14:66-68.
Gloe S, Rothering A, Kiland JA, McLellan GJ. Validation of the Icare (R) TONOVET plus rebound tonometer in normal rabbit eyes. Exp Eye Res. 2019;185:107698.
Lim KS, Wickremasinghe SS, Cordeiro MF, Bunce C, Khaw PT. Accuracy of intraocular pressure measurements in New Zealand white rabbits. Invest Ophthalmol Vis Sci. 2005;46:2419-2423.
Abrams LS, Vitale S, Jampel HD. Comparison of three tonometers for measuring intraocular pressure in rabbits. Invest Ophthalmol Vis Sci. 1996;37:940-944.
Bertens CJF, van Mechelen RJS, Berendschot TTJM, et al. Repeatability, reproducibility, and agreement of three tonometers for measuring intraocular pressure in rabbits. Sci Rep-Uk. 2021;11:11.
Chui WS, Lam A, Chen D, Chiu R. The influence of cornea properties on rebound tonometry. Ophthalmology. 2008;115:80-84.
Processing Request
No Comments.