Sphenopalatine sinus syndrome in a horse

A 14-years-old Arabian mare, presented for clinical consultation with a 2-months history of chronic nasal discharge and recurrent epistaxis, showed a bilateral blindness and blepharospasmus. On the basis of the neuro-ophtalmological examina- tion and ancillary procedures a paranasal sinus pathology with sphenopalatine sinus involvement was suspected. At post- mortem examination impinging of the optic chiasm by a sinus tumor was confirmed. Histopathology revealed a squamous cell carcinoma of the paranasal sinus. The neuro-opthalmological picture of sphenopalatine sinus syndrome has been theori- zed in horses on the basis of the complex anatomy of that sinus cavity. A few anecdotal cases had been reported in literature. This case demonstrated as disorders involving the sphenopalatine sinus could cause a major dysfunction of the optic pathways and trigeminal nerve. These disorders need to be taken in account in the differential diagnosis of sudden blindness of horses