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Home / Equine Research Bank / Vet Ophthalmol / Computed tomographic dimensions of the normal adult equine e...
Veterinary ophthalmology2019; 22(5); 651-659; doi: 10.1111/vop.12636

Computed tomographic dimensions of the normal adult equine eye.

Abstract: There are limited data on whether the dimensions of the equine eye and its internal structures change with bodyweight in horses. The aim of this study was to identify whether the size of the equine eye and its individual structures varied in a predictable manner with bodyweight, and to examine the reliability of computed tomography (CT) scans in the measurement of the equine eye. Ninety horses which had undergone CT examination of the head for non-ocular disease were included. All measurements of the eye were performed twice on all eyes by the same operator to quantify intra-operator agreement, and in 10 cases were also performed by a second operator to quantify inter-operator agreement. Agreement was excellent for all but the rostrocaudal measurement of the anterior chamber, which was fair. The following variables correlated significantly with bodyweight: anterior-posterior size of the globe (correlation coefficient: 0.586) and posterior segment (correlation coefficient: 0.554); the latero-medial size of the globe (correlation coefficient: 0.452), anterior chamber (correlation coefficient: 0.504) and posterior segment (correlation coefficient: 0.455); and the orbital fossa diameter (correlation coefficient: 0.219). The lens size and anterior-posterior distance of the anterior chamber did not correlate significantly with bodyweight. These results suggest that overall eye size and the size of the orbital fossa change with the bodyweight of the horse, but lens size remains consistent, and that CT measurements of the internal structures of the eye are repeatable and reproducible. This information aids in interventional procedures for ocular pathology and assessment of normal anatomy.
© 2019 American College of Veterinary Ophthalmologists.
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Publication Date: 2019-02-04 PubMed ID: 30716192DOI: 10.1111/vop.12636Google Scholar: Lookup
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Summary

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The research article focuses on understanding if the size of a horse’s eye and its internal structures vary predictably with the horse’s bodyweight. The study also explores the reliability of CT scans in measuring the equine eye. The results reveal that the overall eye size and the size of the orbital fossa do change with the horse’s bodyweight, while the lens size remains constant. CT measurements of the eye’s internal structures were found to be consistent and replicable.

Research Methodology

  • The study took into account ninety horses that had undergone computed tomography (CT) examination of the head for non-ocular diseases.
  • All measurements of their eyes were performed twice by the same operator to determine intra-operator agreement.
  • In 10 cases, a second operator also performed the measurements to ascertain inter-operator agreement.

Key Research Findings

  • Agreement between the measurements was found to be excellent except for the rostrocaudal measurement of the anterior chamber, which was fair.
  • The study found a significant correlation between the bodyweight of horses and various dimensions of the globe, anterior chamber, posterior segment, and the orbital fossa.
  • However, the lens size and anterior-posterior distance of the anterior chamber did not show a significant correlation with bodyweight, indicating that the lens size remains consistent irrespective of the bodyweight of the horse.
  • The reliability of CT scans in measuring the internal structures of the eye were found to be repeatable and reproducible, proving the effectiveness of this measurement method.

Implications and Uses of Research Findings

  • The findings aid in undertaking interventional procedures for ocular pathology because a better understanding of the equine eye structure in relation to bodyweight can lead to more precise treatments.
  • Moreover, the research provides a benchmark for assessing normal equine eye anatomy, which helps in the accurate diagnosis and treatment of eye-related issues in horses.

Cite This Article

APA
Hollis AR, Dixon JJ, Berlato D, Murray R, Weller R. (2019). Computed tomographic dimensions of the normal adult equine eye. Vet Ophthalmol, 22(5), 651-659. https://doi.org/10.1111/vop.12636

Publication

Veterinary ophthalmology
ISSN: 1463-5224
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 22
Issue: 5
Pages: 651-659

Researcher Affiliations

Hollis, Anna R
  • The Animal Health Trust, Lanwades Park, Suffolk, UK.
Dixon, Jonathon J
  • Rainbow Equine Hospital, North Yorkshire, UK.
Berlato, Davide
  • The Animal Health Trust, Lanwades Park, Suffolk, UK.
Murray, Rachel
  • The Animal Health Trust, Lanwades Park, Suffolk, UK.
Weller, Renate
  • The Royal Veterinary College, Hertfordshire, UK.

MeSH Terms

  • Animals
  • Eye / anatomy & histology
  • Female
  • Horses / anatomy & histology
  • Male
  • Organ Size
  • Reference Values
  • Retrospective Studies
  • Tomography, X-Ray Computed / veterinary

References

This article includes 17 references
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Citations

This article has been cited 3 times.
  1. Díaz-Bertrana ML, Pitti L, Ramírez AS, Encinoso M, Fumero-Hernández M, Morales I, Arencibia A, Jaber JR. Computed Tomographic Assessment of Normal Ocular Dimensions and Densities in Cadaveric Horses (Equus ferus caballus). Animals (Basel) 2025 Oct 31;15(21).
    doi: 10.3390/ani15213165pubmed: 41227495google scholar: lookup
  2. Goody N, Israeliantz N, Massidda A, Richardson J, Blacklock B, Mitchell J, Liuti T. Ocular biometry in rabbits using computed tomography. Vet Ophthalmol 2024 Nov;27(6):530-539.
    doi: 10.1111/vop.13209pubmed: 38468158google scholar: lookup
  3. Yoo H, Lee S, Shin KY, Seo JP. Computed tomographic dimensions and densities of the normal eye in Jeju horses. J Vet Med Sci 2024 Mar 16;86(3):308-311.
    doi: 10.1292/jvms.23-0382pubmed: 38171740google scholar: lookup
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