Publikationsdatenbank

Calibration of the rebound tonometer Tono Vet for the use in birds of prey (2009)

Art

Vortrag

Autoren

Reuter, A.

Müller, K. (WE 20)

Eule, C. (WE 20)

Kongress

Annual Meeting of the European College of Veterinary Ophthalmologists

Dänemark, 03. – 07.06.2009

Quelle

Veterinary Ophthalmology; 12(6, Abstract Nr. 30) — S. 387

ISSN: 1463-5216

Sprache

Englisch

Verweise

DOI: 10.1111/j.1463-5224.2009.00712.x

Kontakt

Klinik für kleine Haustiere

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14163 Berlin
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email: kleintierklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Purpose: The TonoVet (Tiolat/Icare, Finland) has already been used for measuring IOP in birds
of prey. However, data on calibration of the instrument for use in birds are missing, and have therefore
been the aim of this study. Methods: Ocular health was confirmed intra vitamin. Freshly enucleated
eyes were cannulated with a 20G-needle and connected to a digital manometer (ATP
GmbH, Germany). IOP was set at 5 mmHg steps from 5 to 60 mmHg by adjusting the height of a
NaCl-solution reservoir connected to the needle. At each step, IOP-readings were obtained with the
TonoVet (internal calibration ‘d’). Regression analysis in SPSS was used to calculate the correlation
between manometric and tonometric values. Results: The TonoVet increasingly overestimates
IOP in White-tailed Eagles (Haliaeetus albicilla), Common Buzzards (Buteo buteo) and Goshawks
(Accipiter gentilis) with increasing IOP. Formulae for regression are as follows: y ¼ )1.20 + 1.60x
(n ¼ 13 eyes, r2 ¼ 0.992, standard error of the estimate, SEE ¼ 2.54), y ¼ 1.08 + 1.45x (n ¼ 21,
r2 ¼ 0.994, SEE ¼ 2.07), and y ¼ )1.66 + 1.37x (n ¼ 5, r2 ¼ 0.997, SEE ¼ 1.27), respectively. In
Eurasian Sparrowhawks (Accipiter nisus) TonoVet values almost represent the ideal line (y ¼
0.67 + 0.97x, n ¼ 14, r2 ¼ 0.998, SEE ¼ 0.68). In Tawny Owls (Strix aluco) and Long-eared Owls
(Asio otus), the TonoVet increasingly underestimates IOP with increasing pressure. Regression formulae
are y ¼ )2.92 + 0.97x (n ¼ 6, r2 ¼ 0.992, SEE ¼ 1.56) and y ¼ )2.30 + 0.80x (n ¼ 4, r2 ¼
0.997, SEE ¼ 0.84), respectively. Conclusion: IOP values measured with the TonoVet show
great variations among the different species. In order to interpret tonometric findings, these differences
need to be considered. Using the presented regression formulae, corrected IOP values can be
calculated.