DDx: Neuro-Ophthalmic Disorders

Question 1

Ddx: Neuro-Ophthalmic Disorders

Answer 1

Monocular Disorders

Question 2

Monocular Disorders

Answer 2

Transient monocular blindness (amaurosis fugax) is characterized by typically painless, unilateral transient diminution or loss of vision that develops over seconds, remains maximal for 1 to 5 minutes, and resolves over 10 to 20 minutes. Most cases result from transient ischemia of the optic nerve or retina.

Hx: The description of a curtain descending over the visual field is highly suggestive of this diagnosis. The most common etiology is retinal ischemia due to atherosclerotic emboli originating from the ipsilateral carotid artery

Dx: Patients with vascular risk factors (eg, hypertension, hyperlipidemia, smoking) should be evaluated with a duplex ultrasound of the neck. Funduscopic examination is often normal but may show embolic plaques and retinal whitening (due to ischemia).

Tx: Diagnostic evaluation and treatment of patients with transient monocular blindness resemble that for patients with hemispheric TIAs.

Autoimmune optic neuritis The most common cause is demyelination
(acute demyelinating optic neuritis). Unilateral impairment of visual acuity occurs over hours to days, becoming maximal within 2 weeks. Visual loss is associated with headache, globe tenderness, or eye pain in more than 90% of patients; the pain is typically exacerbated by eye movement. Visual field testing demonstrates a central scotoma (blind spot) associated with decreased visual acuity. The pupils are equal in size but show less pronounced constriction in response to illumination of the affected eye (relative afferent pupillary defect; Marcus Gunn pupil). Recovery of vision begins in a few weeks and may progresses for a year. Normal vision returns in the majority. Optic neuritis is the first manifestation of multiple sclerosis in 25% of cases and occurs in 70% of multiple sclerosis patients at some point. Bilateral spontaneous optic neuritis and transverse myelitis occur in neuromyelitis optica (NMO) spectrum
disorder, formerly called Devic disease. The presence of aquaporin-4 antibodies is diagnostic.

Less reversible visual loss of sudden onset occurs in idiopathic ischemic optic neuropathy and in giant cell (temporal) arteritis.

Question 3

Binocular Disorders

Answer 3

Papilledema is painless, passive, typically bilateral disk swelling associated with increased intracranial pressure.

Chiasmal Lesions

Retro-chiasmal Lesions

Question 4

Ophthalmic Disorders

Answer 4

Hx: Pain about the eye may occur in migraine and cluster headache and is also the presenting feature of iritis and glaucoma.

Acute iritis produces extreme eye pain with photophobia. The diagnosis is confirmed by slit lamp examination; acute management involves pharmacologic dilatation of the pupil.

Angle-closure glaucoma produces pain within the globe that radiates to the forehead. When it occurs after middle age, such a pain syndrome should prompt diagnostic tonometry.