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Home / Equine Research Bank / Vet Ophthalmol / Comparison of two rebound tonometers in healthy horses.
Veterinary ophthalmology2020; 23(5); 892-898; doi: 10.1111/vop.12819

Comparison of two rebound tonometers in healthy horses.

Abstract: To obtain a reference range for evaluation of intraocular pressure (IOP) in horses using Tonovet Plus , to compare the IOP readings obtained with Tonovet and Tonovet Plus , and to evaluate the repeatability of readings. Unassigned: Intraocular pressure of 30 client-owned horses (60 eyes) with no signs of illness or ocular disease was evaluated using Tonovet and Tonovet Plus rebound tonometers. Horses' mean age was 10.7 (range 6-17) years. Triplicate measurements were performed without using sedatives or local anesthetics, with minimal restraint. Results: Calculated reference intervals (the CLSI robust method) were 14.4-27.2 mmHg for Tonovet and 16.0-26.1 mmHg for Tonovet Plus . Mean values (± standard deviation, SD [± coefficient of variation, CV]) obtained with Tonovet Plus (21.6 ± 2.45 mmHg [11.3%]) were on average 0.6 mmHg higher than with Tonovet (21.0 ± 3.14 mmHg [15.0%]), and a negligible statistical difference between the devices was found using the paired sample t test (P = .049). The correlation coefficient for the averaged triplicate measurements was 0.73. The average CV was 4.6% and 4.4% for Tonovet and Tonovet Plus , respectively. Conclusions: The repeatability of measurements was very good with both devices. The readings between the two devices differed statistically significantly, but the correlation was considered good and the variation was numerically small, and thus, the difference was considered clinically irrelevant. When monitoring disease process or treatment response in an individual patient, repeated readings are best performed using a similar device to avoid false interpretation of results.
© 2020 The Authors. Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.
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Publication Date: 2020-09-04 PubMed ID: 32888242PubMed Central: PMC7540552DOI: 10.1111/vop.12819Google Scholar: Lookup
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  • Comparative Study
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research study assessed the reliability and comparison of intraocular pressure (IOP) measurements taken from horses using two different tonometers, Tonovet and Tonovet Plus. The findings suggest that the measurements from both devices were generally consistent, albeit statistically significant, but the difference was considered clinically insignificant for evaluating eye health in horses.

Methodology

  • The study involved 30 horses, ranging in age from 6-17 years, that were in good health and showed no signs of ocular disease.
  • Both eyes of each horse were tested using both Tonovet and Tonovet Plus rebound tonometers, making a total of 60 eyes.
  • To eliminate possible variables, no sedatives or local anesthetics were used during the procedure, and minimal restraint of the horses was employed.
  • Each device took three measurements per eye, and these values were averaged to achieve a final result.

Results

  • The reference intervals calculated by the CLSI robust method were 14.4-27.2 mmHg for the Tonovet and 16.0-26.1 mmHg for Tonovet Plus.
  • The mean IOP recorded by Tonovet Plus was slightly higher (by 0.6 mmHg) than that recorded by Tonovet, an insignificant difference statistically.
  • The correlation coefficient for averaged triplicate measurements was 0.73, demonstrating a strong correlation between the measurements from the two devices.
  • The average coefficient of variation was 4.6% for Tonovet and 4.4% for Tonovet Plus, affirming the repeatability of measurements using both devices was very good.

Conclusion

  • Despite statistically significant differences, the correlation between readings of the two devices was good, and the variation was numerically small, making the difference clinically irrelevant.
  • For consistent results, it is recommended to use the same device when taking repeated IOP readings. This is to avoid false interpretation of results while monitoring any disease process or response to treatment in a patient.

Cite This Article

APA
Mustikka MP, Pietilä EM, Mykkänen AK, Grönthal TSC. (2020). Comparison of two rebound tonometers in healthy horses. Vet Ophthalmol, 23(5), 892-898. https://doi.org/10.1111/vop.12819

Publication

Veterinary ophthalmology
ISSN: 1463-5224
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 23
Issue: 5
Pages: 892-898

Researcher Affiliations

Mustikka, Minna P
  • Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
Pietilä, Elina M
  • Veterinary Clinic Apex, Helsinki, Finland.
Mykkänen, Anna K
  • Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
Grönthal, Thomas S C
  • Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.

MeSH Terms

  • Animals
  • Eye
  • Female
  • Horses / physiology
  • Intraocular Pressure
  • Male
  • Reference Values
  • Tonometry, Ocular / instrumentation
  • Tonometry, Ocular / veterinary

Conflict of Interest Statement

The authors thank Icare Finland Oy for providing the Tonovet Plus device and the probes needed to perform this study. Icare Finland did not influence study design or the collection, analysis, or interpretation of data. None of the authors has a financial relationship with Icare Finland Oy that could influence or bias the study content.

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Citations

This article has been cited 1 times.
  1. Stas EKL, Hermans H, Slenter IJM, Veraa S, Ensink JM. Noninvasive diode laser-an effective and safe treatment of iris cysts in 46 eyes of 35 horses.. Equine Vet J 2023 Mar;55(2):205-213.
    doi: 10.1111/evj.13590pubmed: 35575001google scholar: lookup
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