Peer-reviewed veterinary case report
Horse with severe vision loss due to sinus infection and nerve
By Holz, Niklas et al.·Published in Veterinary ophthalmology·2026·Vetsuisse Faculty·View original on PubMed →
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Original publication title: Mycotic Sphenopalatine Sinusitis With Concurrent Compression of the Optic Nerves and Chiasm and Severe Visual Impairment in A Horse.
- Species:
- horse
Plain-English summary
A 15-year-old Swiss Warmblood gelding was taken to the veterinary hospital because he was having serious trouble seeing. After a thorough eye and neurological exam, the vets suspected he might have post-retinal blindness, which means the issue was behind the retina in the eye. A special scan of his head showed a mass in the sphenopalatine sinus (a space in the skull) that was pressing on the optic nerves, which are responsible for vision. Unfortunately, the horse was euthanized, and further tests revealed that the mass was caused by a fungal infection, leading to inflammation and damage to the optic nerves. This case highlights that mycotic sphenopalatine sinusitis (a fungal infection in the sinus) can lead to vision problems in horses.
Abstract
A 15-year-old Swiss Warmblood gelding was presented to the ophthalmology service of Zurich University due to severe visual impairment. Ophthalmic and neurologic examinations were performed, raising suspicion of post-retinal blindness. Standing contrast computed tomography (CT) of the head revealed a partially calcified, soft tissue attenuating mass in the sphenopalatine sinus with concurrent compression of the optic nerves and chiasm. Differential diagnosis included neoplasia and granulomatous disease. The horse was euthanized, and the head was subsequently examined by magnetic resonance imaging (MRI) followed by gross and histopathology. MRI showed compression of the optic nerves and chiasm. Histopathology revealed the formation of fibrous granulation tissue, osseous metaplasia, and pyogranulomatous inflammation in the sphenopalatine sinus. Periodic acid-Schiff reaction and Grocott silver staining demonstrated branching septated filament hyphae and fungal spores. The optic nerves and chiasm were evident of mild neuronal atrophy, showing mild gliosis, vacuolation, and mild lympho-plasmacytic inflammation. Mycotic sphenopalatine sinusitis should be considered as a more specific diagnosis for post-retinal blindness in horses due to the compression of the optic nerve(s) and chiasm.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/40055139/