The optic nerve carries images of what the eye sees to the brain. When this nerve become swollen or inflamed, it is called optic neuritis. It may cause sudden, reduced vision in the affected eye.

Retro-bulbar neuritis; Multiple sclerosis - optic neuritis; Optic nerve - optic neuritis

The exact cause of optic neuritis is unknown.

The optic nerve carries visual information from your eye to the brain. The nerve can swell when it becomes suddenly inflamed. The swelling can damage nerve fibers. This can cause short or long-term loss of vision.

Conditions that have been linked with optic neuritis include:

• Autoimmune diseases, including lupus, sarcoidosis, and Behçet disease
• Cryptococcosis, a fungal infection
• Bacterial infections, including tuberculosis, syphilis, Lyme disease, and meningitis
• Viral infections, including viral encephalitis, measles, rubella, chickenpox, herpes zoster, mumps, and mononucleosis
• Respiratory infections, including mycoplasma pneumonia and other common upper respiratory tract infections
• Multiple sclerosis

Symptoms may include:

• Loss of vision in one eye over an hour or a few hours
• Changes in the way the pupil reacts to bright light
• Loss of color vision
• Pain when you move the eye

Vision often returns to normal within 2 to 3 weeks with no treatment.

Corticosteroids given through a vein (IV) or taken by mouth (oral) may speed up recovery. However, the final vision is no better with steroids than without. Oral steroids may actually increase the chance of recurrence.

If tests suggest that there is also multiple sclerosis, certain forms of interferon may be helpful.

Further tests may be needed to try to find the cause of the neuritis. If there is a condition causing the problem, it may be able to be treated.

When optic neuritis occurs without other diseases, there is a better prognosis. An MRI is an important test because it can help predict if multiple sclerosis or other similar autoimmune diseases are present or may develop.

Optic neuritis caused by multiple sclerosis or other autoimmune diseases has a poorer outlook. However, vision in the affected eye may still return to normal.

Complications may include:

• Body-wide side effects from corticosteroids
• Vision loss

Some people who have an episode of optic neuritis will develop nerve problems in other places in the body or develop multiple sclerosis.

Contact your health care provider right away if you have a sudden loss of vision in one eye, especially if you have eye pain.

If you have been diagnosed with optic neuritis, contact your health care provider if:

• Your vision decreases.
• The pain in the eye gets worse.
• Your symptoms do not improve within 2 to 3 weeks.

Published Date: February 17, 2022
Published By: Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

Bennett JL. Optic neuritis. Continuum (Minneap Minn). 2019;25(5):1236-1264. PMID: 31584536 pubmed.ncbi.nlm.nih.gov/31584536/.

Calabresi PA. Multiple sclerosis and demyelinating conditions of the central nervous system. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 383.

Filipi M, Jack S. Interferons in the treatment of multiple sclerosis: a clinical efficacy, safety, and tolerability update. Int JMS Care. 2020;22(4):165-172. PMID: 32863784 pubmed.ncbi.nlm.nih.gov/32863784/.

Moss HE, Guercio JR, Balcer LJ. Inflammatory optic neuropathies and neuroretinitis. In: Yanoff M, Duker JS, eds. Ophthalmology.  5th ed. Philadelphia, PA: Elsevier; 2019:chap 9.7.

Thurtell MJ, Prasad S, Tomsak RL. Neuro-ophthalmology: afferent visual system. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 16.