Etiology of Compressive Optic Neuropathy
Compressive optic neuropathy is often caused by a tumor, such as an orbital or pituitary tumor. Inflammation (such as from orbital pseudotumor) or other diseases (such as thyroid eye disease) are also possible causes.
Symptoms and Signs of Compressive Optic Neuropathy
Compressive optic neuropathy from a tumor or mass usually causes slow, painless, progressive loss of vision. It usually affects one eye and typically affects central vision, except for tumors in the pituitary gland, which can compress the optic chiasm. Compression of the optic chiasm causes bilateral loss of peripheral vision (bitemporal hemianopia).
Diagnosis of Compressive Optic Neuropathy
Visual fields are evaluated for potential central and peripheral vision loss, which usually slowly worsen in the setting of compressive optic neuropathy. On fundoscopy, the optic nerve can be swollen, pale, or appear normal. Optical coherence tomography is done to evaluate the optic nerve and may show thickening or atrophy of the optic nerve. Neuroimaging (usually magnetic resonance imaging [MRI]) is done to find any mass or tumor that is pressing on the optic nerve.
Treatment of Compressive Optic Neuropathy
Treatment depends on the cause of the compressive optic neuropathy. Usually surgery is required to remove or debulk the mass. Besides surgery, radiation is used for some tumors. Medical treatment may be indicated for certain causes (eg, thyroid eye disease). Vision improves after surgery in some patients.