Evaluation of the effects of age and pituitary pars intermedia dysfunction on corneal sensitivity in horses.
- Journal Article
- Adult Horses
- Age Factors
- Animal Health
- Animal Studies
- Clinical Study
- Cornea
- Diagnosis
- Disease Diagnosis
- Disease Etiology
- Equine Diseases
- Equine Health
- Geriatric Horses
- Horses
- Observational Study
- Ophthalmology
- Pathophysiology
- Physiology
- Pituitary Pars Intermedia Dysfunction
- Veterinary Medicine
- Veterinary Research
- Young Horses
Summary
The research paper investigates the impact of age and pituitary pars intermedia dysfunction (PPID) on the corneal sensitivity of horses.
Study Design and Methodology
The study involved 20 adult horses which were categorised into three groups based on their age and condition status:
- PPID group: Old horses (>15 years old) diagnosed with PPID (5 horses).
- Old group: Old horses (>15 years old) without PPID (9 horses).
- Young group: Young horses (≤10 years old) without PPID (6 horses).
All horses classified as having PPID exhibited hirsutism, abnormal fat distribution, or laminitis, conditions not present in the horses of the old and young groups.
A Cochet-Bonnet aesthesiometer, a device specifically designed to measure corneal sensitivity, was used to establish the corneal touch threshold (CTT) in both eyes of each horse. The length of the nylon filament was gradually reduced from a maximum of 60mm until a consistent blink response was observed, indicating perceptible tactile sensitivity. Additionally, tear production, an important factor for eye health, was assessed using the Shirmer tear test (STT).
Research Findings
Results from the study revealed noticable differences across the groups:
- The young group showed significantly higher corneal sensitivity (47.50 ± 4.52 mm) compared to both the old (28.06 ± 5.72 mm) and PPID (21.5 ± 3.37 mm) groups.
- Old horses presented higher CTT values, indicating more sensitivity compared to horses with PPID.
- The tear production, assessed by STT, was found to be within the reference range across all groups and did not show any significant variation.
Conclusion and Implications
This research confirmed a decrease in corneal sensitivity among horses with advancing age and presence of PPID. Since reduced corneal sensitivity can result in impaired wound healing, the study suggests that aging or having PPID can increase the risk of nonhealing or recurring corneal ulcers in horses. This understanding may inform subsequent research to develop effective interventions for maintaining eye health in horses, especially among older horses or those with PPID.
Cite This Article
Publication
Researcher Affiliations
- Department of Clinical Sciences, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348, USA.
MeSH Terms
- Aging
- Animals
- Cornea / physiology
- Female
- Horse Diseases / etiology
- Horses
- Male
- Pituitary Diseases / complications
- Pituitary Diseases / pathology
- Pituitary Diseases / veterinary
- Pituitary Gland, Intermediate / pathology
Citations
This article has been cited 4 times.- Hargitaiova K, Maleas G. High-metacarpal deep digital flexor tenotomy and Steward clog shoeing for managing chronic refractory laminitis: A retrospective clinical study. Vet Surg 2026 Jan;55(1):236-247.
- Kirkwood NC, Hughes KJ, Stewart AJ. Prospective Case Series of Clinical Signs and Adrenocorticotrophin (ACTH) Concentrations in Seven Horses Transitioning to Pituitary Pars Intermedia Dysfunction (PPID). Vet Sci 2022 Oct 17;9(10).
- Telle MR, Chen N, Shinsako D, Kiland JA, Oikawa K, Møller Trane R, McLellan GJ. Relationship between corneal sensitivity, corneal thickness, corneal diameter, and intraocular pressure in normal cats and cats with congenital glaucoma. Vet Ophthalmol 2019 Jan;22(1):4-12.
- Ezuddin NS, Alawa KA, Galor A. Therapeutic Strategies to Treat Dry Eye in an Aging Population. Drugs Aging 2015 Jul;32(7):505-13.
