Blindness, optic atrophy and sinusitis in the horse.

This research looks at three cases of horses experiencing varying degrees of visual impairment, all of whom had a previously reported upper respiratory tract infection. Using a combination of methods, including specialist examination and MRI scanning, the researchers found a common cause in all three cases: infection of the spheno-palatine sinuses causing distortion and pressure on the optic nerves, leading to the observed visual problems.

Introductory Details

• This study focuses on three case histories of horses with a diverse range of ages and breeds but sharing a history of upper respiratory tract infection.
• All the cases showed symptoms of visual deficit including occasional or total blindness, and varying ophthalmoscopic abnormalities.
• The consistent factor in all cases investigated was an infection of the spheno-palatine sinuses causing pressure on the adjacent optic nerve(s) and optic chiasm resulting in visual disturbances.

Methods

• All the horses involved in the study were examined by a specialist veterinary ophthalmologist.
• Magnetic Resonance Imaging (MRI) technology was used to ascertain the underlying condition causing the visual disturbances in the horses.
• When possible, postmortem, and histopathological tests were carried out to further scrutinize the cause of the visual disturbance.

Results & Conclusions

• Upon investigation, the veterinary ophthalmological examination was found to be of limited value.
• The MRI and CT scans were instrumental in accurately diagnosing the cause which was found to be infections distorting the spheno-palatine sinuses and compressing the optic nerves.
• This discovery emphasized the importance of using such methods for effective diagnosis and potential successful treatment.
• The study made comparisons to similar cases in humans, where visual disturbances due to spheno-palatine sinus issues are known but rare.