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Veterinary ophthalmology2003; 6(3); 251-254; doi: 10.1046/j.1463-5224.2003.00302.x

Schirmer tear test results in normal horses and ponies: effect of age, season, environment, sex, time of day and placement of strips.

Abstract: Tear production was evaluated in 39 horses and 29 ponies using Schirmer tear test strips to determine whether diurnal or weekly fluctuations occur, whether location of strip placement has an effect, if values are the same for both eyes in an animal and whether sex, age, stabling vs. pasture and winter vs. summer had an effect. There was no test in which the raw score was less than 10 mm, although there were many occasions where tear wetting exceeded 35 mm. Analysis of the raw (continuous) scores by linear regression provided no evidence that signalment, housing or season or location of strip placement affected results. The distribution of tear test scores for a 'population' of eyes did not differ when the right eye was compared with the left eye or when the same eye was compared at different times on the same day. Individual test wetting values for opposing eyes measured at the same time, and also wetting values for the same eye measured at different times on the same day sometimes differed substantially. In winter maximum tear wetting exceeded 35 mm more frequently in the STT I than in the STT II even in housed horses and ponies, but there was no consistent significant difference. There appears to be wide variability in the STT I in normal horses and ponies.
Publication Date: 2003-09-03 PubMed ID: 12950657DOI: 10.1046/j.1463-5224.2003.00302.xGoogle Scholar: Lookup
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  • Journal Article

Summary

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The research attempted to understand factors affecting tear production in horses and ponies using Schirmer tear test strips. It found that apart from some fluctuations in both an individual’s left and right eyes or in the same eye at different times of the day, there were no major impacts from age, gender, environment, season, and time of day on tear production.

Objective of the Research

  • The study aimed to investigate tear production in normal horses and ponies, and whether various factors influenced it. These factors include daily and weekly fluctuations, strip placement, the similarity of values in both eyes of an animal, and the impacts of sex, age, environment (stabling vs. pasture), and season (winter vs. summer).

Methodology

  • The research used Schirmer tear test strips to analyse tear production in 39 horses and 29 ponies. This involved measuring tear wetness, with scores below 10 mm and above 35 mm considered noteworthy.
  • The analysis of the scores was done by linear regression to determine whether there were significant differences affected by factors such as signalment, housing, season, or strip placement.

Findings

  • The study found that none of the considered factors significantly affected the tear test scores. This means that tear wetness in animals was not influenced by factors like age, sex, season, or the time of day.
  • However, there were some fluctuations in the tear test scores. These fluctuations occurred between the left and right eyes of the same animal and in the same eye at different times of the day.
  • In winter, maximum tear wetting was more prevalent in certain instances but there was no significant, consistent difference.
  • The authors note that there is a high variability in the Schirmer Tear Test I in normal horses and ponies, meaning that tear production can significantly vary on an individual basis.

This indicates a need for further investigation into what might cause these individual variations and whether there might be other influencing factors that were not included in this study.

Cite This Article

APA
Beech J, Zappala RA, Smith G, Lindborg S. (2003). Schirmer tear test results in normal horses and ponies: effect of age, season, environment, sex, time of day and placement of strips. Vet Ophthalmol, 6(3), 251-254. https://doi.org/10.1046/j.1463-5224.2003.00302.x

Publication

ISSN: 1463-5216
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 6
Issue: 3
Pages: 251-254

Researcher Affiliations

Beech, J
  • Section of Medicine, University of Pennsylvania, New Bolton Center, Kennett Sq., PA, USA. jbeech3085@vet.upenn.edu
Zappala, R A
    Smith, G
      Lindborg, S

        MeSH Terms

        • Animals
        • Circadian Rhythm
        • Environment
        • Female
        • Horses / physiology
        • Male
        • Reagent Strips
        • Reference Values
        • Seasons
        • Tears / metabolism

        Citations

        This article has been cited 12 times.
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        11. Aftab G, Rajaei SM, Faghihi H. Comparison of the Schirmer tear test I values after placement in ventral and dorsal conjunctival fornices in healthy cats. J Feline Med Surg 2018 Dec;20(12):1169-1172.
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