Blindness, optic atrophy and sinusitis in the horse.
OBJECTIVE
The case histories described each presented with a visual deficit, varying from permanent total blindness with ophthalmoscopic evidence of optic atrophy to variable and transient visual disturbances, including occasional blindness, but with absence of ophthalmoscopic or any other ocular abnormality.


METHODS
Three horses of widely different age and type, but all with an original history of upper respiratory tract infection.


METHODS
All three cases were examined by a specialist veterinary ophthalmologist. In addition, magnetic resonance imaging (MRI) and, where possible, postmortem and histopathological examinations were performed.


RESULTS
The common factor to all three cases proved to be infection of the spheno-palatine sinuses with subsequent distension and compression of adjacent optic nerve(s) and optic chiasm.


CONCLUSIONS
Specialist veterinary ophthalmological examination proved of extremely limited value. The importance of MRI (and CT) scans for accurate diagnosis, and therefore possible successful treatment, is emphasized. Our cases were compared with similar cases in man, where visual disturbances due to spheno-palatine sinus involvement are recognized, but rare, in similar situation.
Barnett
K C
KC
Center for Small Animal Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, UK. keith.barnett@aht.org.uk
Blunden
A S
AS
Dyson
S J
SJ
Whitwell
K E
KE
Carson
D
D
Murray
R
R
D000818:Animals; D001766:Blindness / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary*; D017809:Fatal Outcome; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis*; D006736:Horses; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary; D008297:Male; D009896:Optic Atrophy / Q000175:diagnosis / Q000662:veterinary*; D012852:Sinusitis / Q000150:complications / Q000175:diagnosis / Q000662:veterinary*