Veterinary Research Forum

Two-dimensional ultrasonography study of normal ocular structures in Turkmen horse

Document Type : Original Article

Authors

Pouran Mohammadi 1
Farrokhreza Kabir 1
Saeed Ozmaie 1
Saeid Bokaie 2

1 Department of Clinical Sciences, Faculty of Veterinary Medicine, SR.C., Islamic Azad University, Tehran, Iran

2 Department of Epidemiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

10.30466/vrf.2026.2069490.4887
Abstract
Ocular ultrasonography is a safe, painless and non-invasive diagnostic tool that provides veterinarians with detailed images of the eye and surrounding structures. This study evaluated 30 clinically healthy Turkmen horses, divided into two groups as Group 1: under 36 months (3 males, 8 females), and Group 2: 36 months and older (8 males, 11 females). Significant differences in several ocular parameters were identified across different age groups in Turkmen horses. Specifically, the mean intercanthal distance, globe diameter, ciliary body volume and area, iris thickness, corpora nigra distance, volume and area, vitreous chamber and retinal/choroidal/scleral composite size demonstrated statistically significant variations between age categories. No significant differences were detected between sexes within any of the age groups for above measured parameters. Of the ocular parameters evaluated, only anterior chamber depth, central lens thickness and ciliary body thickness demonstrated statistically significant differences based on both sex and age. The average corneal thickness of the left and right eyes, as measured in sagittal and dorsal planes, was similar in both male horses under 36 months and those 36 months or older when compared to their respective female counterparts. No significant differences were observed between measurements of the left and right eyes, nor were there significant discrepancies between sagittal and dorsal measurements. These findings provided a baseline for understanding normal ocular ultrasonographic features in Turkmen horses and might aid in diagnosis and management of ocular diseases specific to this breed.

Keywords

Equine
Ocular structures
Turkmen horse
Ultrasonography
Subjects
1.     Diaz OS. Ultrasound of the equine eye and adnexa and clinical applications. Clin Tech Equine Pract 2004; 3(3): 317-325.
2.     Valentini S, Tamburro R, Spadari A, et al. Ultrasonographic evaluation of equine ocular diseases: a retrospective study of 38 eyes. J. Equine Vet Sci 2010; 30(3): 150-154.
3.     Hallowell G, Bowen IM. Practical ultrasonography of the equine eye. Equine Vet Educ 2007; 19: 600-605.
4.     Scotty NC. Ocular ultrasonography in horses. Clin Tech Equine Pract 2005; 4(1): 106-113.
5.     Scotty NC, Cutler TJ, Brooks DE, et al. Diagnostic ultrasonography of equine lens and posterior segment abnormalities. Vet Ophthalmol 2004; 7(2): 127-139
6.     Gonzalez EM, Rodriguez A, Garcia I. Review of ocular ultrasonography. Vet Radiol Ultrasound 2001; 42(6): 485-495.
7.     Svaldenienė E, Paunksnienė M, Babrauskienė V. Ultrasonographic study of equine eyes. Ultragarsas 2004; 53(4): 49-51.
8.     Cegarra MJ, Izquierdo C, Alonso L, et al. Consolidating the anatomical relationship between ocular axial length and spherical equivalent refraction. Eur J Anat 2001; 5(3): 145-150.
9.     Nelms SR, Nasisse MP, Davidson MG, et al. Hyphema associated with retinal disease in dogs: 17 cases (1986-1991). J Am Vet Med Assoc 1993; 202(8): 1289-1292.
10. Hallowell G, Potter T. Practical guide to ocular ultrasonography in horses and farm animals. In Pract 2010; 32(3): 90-96.
11. Plummer CE, Ramsey DT, Hauptman JG. Assessment of corneal thickness, intraocular pressure, optical corneal diameter, and axial globe dimensions in Miniature Horses. Am J Vet Res 2003; 64(6): 661-665.
12. Grinninger P, Skalicky M, Nell B. Evaluation of healthy equine eyes by use of retinoscopy, keratometry, and ultrasonographic biometry. Am J Vet Res 2010; 71(6): 677-681.
13. Herbig LE, Eule JC. Central corneal thickness measurements and ultrasonographic study of the growing equine eye. Vet. Ophthalmol 2015; 18(6): 462-471.
14. Townsend WM, Wasserman N, Jacobi S. A pilot study on the corneal curvatures and ocular dimensions of horses less than one year of age. Equine Vet J 2013; 45(2): 256-258.
15. Valentini S, Castagnetti C, Musella V, et al. Assessment of intraocular measurements in neonatal foals and association with gender, laterality, and body weight: a clinical study. PLoS One 2014; 9(10): e109491. doi: 10.1371/journal.pone.0109491.
16. Mouney MC, Townsend WM, Moore GE. Association of height, body weight, age, and corneal diameter with calculated intraocular lens strength of adult horses. Am J Vet Res 2012; 73(12): 1977-1982.
17. Soroori S, Masoudifard M, Raoofi A, et al. Ultrasonographic findings of some ocular structures in Caspian miniature horse. Iran J Vet Res 2009; 10(4): 329-333.
Veterinary Research Forum
Volume 17, Issue 8
August 2026
Pages 597-602

  • Receive Date 25 August 2025
  • Revise Date 02 May 2026
  • Accept Date 24 May 2026

Home

Guide for Authors

Submit Manuscript

Reviewers

Contact Us