Veterinary Ophthalmology: Feline Internal Ophthalmoparesis/Ophthalmoplegia

Feline Internal Ophthalmoparesis/Ophthalmoplegia

• Twelve cases of feline internal ophthalmoparesis/ophthalmoplegia were identified, with a median age of 10.54 years (range 5.75 to 13.17) and both sexes of varying breeds affected.
• Clinical signs included abnormal mental status (n = 9; 75%) and additional neurologic abnormalities (n = 10; 83%).
• Magnetic resonance imaging and/or computed tomography (MRI/CT) of the head were performed in ten cats, revealing a mass lesion in all cases with varying locations.

Imaging Findings

• MRI/CT of the head revealed a mass lesion in all cases with varying locations.
• Advanced imaging may be necessary to reach a definitive diagnosis.

Clinical Signs

• Unilateral internal ophthalmoparesis (right eye only (OD) n = 1, 0.08%) or ophthalmoplegia {(total n = 8, 67%), OD = 4, 33%, left eye (OS) = 4, 33%} was present in nine cats (75%).
• Bilateral internal ophthalmoparesis was present in one cat (case 10) at presentation.
• Case 11 had internal ophthalmoparesis OD and internal ophthalmoplegia OS.

Middle Cranial Fossa Syndrome

• Middle cranial fossa syndrome is a clinical disorder characterized by ipsilateral internal ophthalmoparesis/ophthalmoplegia, paresis, or plegia of the extra-ocular muscles (also known as external ophthalmoparesis/ophthalmoplegia) and decreased to absent facial and corneal sensation.
• This is usually due to an intracranial mass or retrobulbar mass invading the orbital fissure or the middle cranial fossa.

Prognosis

• Cats with systemic and neurologic deficits related to internal ophthalmoparesis/ophthalmoplegia have a guarded prognosis due to the high prevalence of neoplasia in this population.