يسعدنا مشاركة دراسة حالة بيطرية تم التقاطها بواسطة محول تصوير العين Quikvue من Dr Vet Viroux.

تم تقديم قطة أوروبية من الذكور البالغة من العمر 8 سنوات من أجل داء الفرق الثنائية دون فقدان الرؤية.

الفحص السريري: No abnormalities were found.

فحص العيون: The menace response and Dazzle reflex were both positive, but the pupillary light reflexes were negative. The iris showed no atrophy, and the fundus was normal.

كان يشتبه في المشاركة العصبية ، and an MRI exam was recommended but not performed at that time.

بعد ثلاثة أشهر ، the cat was presented again with disorientation and vision loss progressing over several days.

الفحص السريري: No abnormalities were found, and blood pressure was normal at 150 mmHg.

فحص العيون: This time, a negative menace response was observed on the right and diminished on the left, with a negative Dazzle reflex. The rest of the examination was unremarkable.

امتحان التصوير بالرنين المغناطيسي was recommended again to explore intracranial causes, which was accepted this time. The MRI revealed a large mass invading the pituitary fossa and optic foramina, along with subtle signs of intracranial hypertension.

توضيح: The nerve fibers responsible for the pupillary light reflex decussate after the optic nerve decussation, caudal to the optic chiasm. This anatomical feature could explain why bilateral mydriasis occurred before vision loss, as these neural pathways do notالمشاركة في الرؤية.