Disorders affecting cranial nerves to extraocular muscles (presence of pain varies by cause)

Cerebrovascular disease affecting pons or midbrain

Older patients, risk factors (eg, hypertension, atherosclerosis, diabetes)

Sometimes internuclear ophthalmoplegia or other neurologic deficits

No pain

MRI

Compressive lesion (eg, aneurysm, tumor)

Often pain (sudden if caused by ruptured aneurysm) and other neurologic deficits

Immediate imaging (CT, MRI)

Idiopathic (usually microvascular)

Occurs in isolation (no other manifestations)

Ophthalmologic referral to check for other deficits

For isolated diplopia, observation for spontaneous resolution

Imaging (MRI, CT) if not resolved in several weeks

Inflammatory or infectious lesions (eg, sinusitis, abscess, cavernous sinus thrombosis)

Constant pain

Sometimes fever or systemic complaints, facial sensory changes, proptosis

CT or MRI

Wernicke encephalopathy

History of significant alcohol abuse, ataxia, confusion

Clinical diagnosis

Mechanical interference with ocular motion (pain is often present)

Graves disease (infiltrative ophthalmopathy usually associated with hyperthyroidism)

Local symptoms: Eye pain, exophthalmos, lacrimation, dry eyes, irritation, photophobia, ocular muscle weakness causing diplopia, vision loss caused by optic nerve compression

Systemic symptoms: Palpitations, anxiety, increased appetite, weight loss, insomnia, goiter, pretibial myxedema

Sometimes eye abnormalities precede thyroid dysfunction

Thyroid function testing

Orbital myositis

Constant eye pain that worsens with eye motion, proptosis, sometimes injection

MRI

Trauma (eg, fracture, hematoma)

Signs of external trauma; apparent by history

CT or MRI

Tumors (near base of skull, in or near sinuses or orbit)

Often pain (unrelated to eye motion), unilateral proptosis, sometimes other neurologic manifestations

CT or MRI

Neuromuscular transmission disorders (typically, pain is absent)

Botulism

Sometimes preceded by gastrointestinal symptoms

Descending weakness, other cranial nerve dysfunction, dilated pupils, normal sensation

Serum and stool testing for toxin

Guillain-Barré syndrome (Miller Fisher variant)

Ataxia, decreased reflexes

Lumbar puncture

Multiple sclerosis

Intermittent, migratory neurologic symptoms, including extremity paresthesias or weakness, visual disturbance, urinary dysfunction

Sometimes internuclear ophthalmoplegia

MRI of brain and spinal cord

Myasthenia gravis

Diplopia intermittent, often with ptosis, bulbar symptoms, weakness that worsens with repeated use of muscle

Ice pack test, single fiber electromyogram (EMG), anti–acetylcholine receptor antibody testing