Equine glaucoma: a histopathologic retrospective study (1999-2012).
Abstract: To characterize and describe the histopathologic findings in equine globes enucleated due to glaucoma. Methods: Medical records at The Ohio State University from 1999 to 2012 were reviewed retrospectively. Signalment, history, and treatment data were collected, and histologic slides of enucleated globes were examined and lesions recorded. Twenty-three eyes from 23 horses were eligible for inclusion in this study. Results: The majority of affected horses were > 15 years of age (65%). The ages ranged from 5 to 35 years (mean = 17.4 years). The left eye was affected in 10 cases (43%) and the right eye in 13 cases (57%). There were 13 mares (56%) and 10 geldings (44%). Quarter Horses (30%), Appaloosas (26%), and Thoroughbreds (22%) were the most common breeds in the study population. The most common histopathologic changes included hypercellularity of the optic nerve (93%), retinal atrophy (89%), corneal vascularization (83%), descemetization of pectinate ligaments (83%), hypercellularity of the anterior corneal stroma (75%), posterior bowing of the iris base (74%), ciliary body atrophy (74%), corneal striae (70%), pars plana elongation (60%), cataract (53%), and collapsed ciliary cleft/trabecular meshwork (52%). Evidence of uveitis (cataract, lymphoplasmacytic infiltration of the uvea, and/or anterior or posterior synechiae) was present in 20/23 eyes (87%). Conclusions: Equine glaucoma most commonly occurs secondary to uveitis with Appaloosas and older horses predisposed. Histologic changes are comparable to prior reports of chronic glaucoma; notable findings not previously described in the horse were posterior bowing of the iris base and relative sparing of the superior retina from atrophy associated with elevated IOP.
© 2013 American College of Veterinary Ophthalmologists.
Publication Date: 2013-07-16 PubMed ID: 23859597DOI: 10.1111/vop.12080Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- 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 study conducted a retrospective review of histopathologic findings in equine globes enucleated due to glaucoma, with the medical records at The Ohio State University from 1999 to 2012 being analyzed. The findings show that equine glaucoma most often strikes as a secondary condition to uveitis, specifically in Appaloosas and elder horses, and shares histopathologic similarities to chronic glaucoma.
Methods
- The team behind the study reviewed past medical records at the Ohio State University. The timeframe of these records spanned from 1999 to 2012.
- The researchers analyzed data related to the horses’ signalment, history, and treatment. They also examined histologic slides of enucleated globes and kept a record of the lesions found.
Results
- A total of 23 eyes from 23 different horses were deemed eligible for inclusion in this study. The majority of these horses were over the age of 15.
- The ages of the horses included in the study ranged from 5 to 35 years, with the mean age coming in at 17.4.
- On breakdown of the affected eyes, 10 cases involved the left eye whilst 13 cases concerned the right eye.
- Of the total cases, 56% were mares and 44% were geldings.
- Various breeds were included in the research, the most common being Quarter Horses (30%), followed by Appaloosas (26%), and Thoroughbreds (22%).
Common Histopathologic Changes
- Hypercellularity of the optic nerve in 93% of cases
- Retinal atrophy in 89% of cases
- Corneal vascularization and descemetization of pectinate ligaments each in 83% of cases
- Hypercellularity of the anterior corneal stroma in 75% of cases
- Posterior bowing of the iris base and ciliary body atrophy each in 74% of cases
- Corneal striae in 70% of cases
- Pars plana elongation in 60% of cases
- Cataract in 53% of cases
- Collapsed ciliary cleft/trabecular meshwork in 52% of cases
Secondary Evidence of Uveitis
- Evidence of uveitis was present in 87% of eyes, identified by cataracts, lymphoplasmacytic infiltration of the uvea, and/or anterior or posterior synechiae.
- The main conclusion that can be drawn from this is that equine glaucoma most frequently occurs secondary to uveitis, particularly in Appaloosas and older horses.
Additional Findings
- The histologic changes witnessed in this study mirror prior reports on chronic glaucoma.
- Finding special mention were indications not previously seen in horses – posterior bowing of the iris base and the superior retina escaping atrophy related to increased intraocular pressure.
Cite This Article
APA
Curto EM, Gemensky-Metzler AJ, Chandler HL, Wilkie DA.
(2013).
Equine glaucoma: a histopathologic retrospective study (1999-2012).
Vet Ophthalmol, 17(5), 334-342.
https://doi.org/10.1111/vop.12080 Publication
Researcher Affiliations
- College of Optometry, The Ohio State University, Columbus, OH, 43210, USA; Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, USA.
MeSH Terms
- Animals
- Female
- Glaucoma / epidemiology
- Glaucoma / pathology
- Glaucoma / veterinary
- Horse Diseases / epidemiology
- Horse Diseases / etiology
- Horse Diseases / pathology
- Horses
- Male
- Ohio / epidemiology
- Retrospective Studies
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
