Optic neuritis occurs when the optic nerve, the pathway that transmits visual information to the brain, becomes inflamed and the myelin sheath that surrounds the nerve is destroyed (a process known as demyelination). Optic neuritis also known retrobulbar neuritis. It is the inflammation of the optic nerve which can lead to total or partial loss of vision. Optic neuritis may be the first episode of a patient who will subsequently develop multiple sclerosis. Optic neuritis usually develops as a result of an auto-immune disorder which can be triggered by a viral infection. The patient may notice blurred or distorted vision, the reduction of colour vision, or a blind spot. The signs and symptoms of optic neuritis may be indications of an autoimmune disorder called multiple sclerosis. There is also often a story of pain with the movement of the eyes, which may precede visual loss. Most patients with optic neuritis experience a sudden onset of decreased vision along with pain and soreness when moving the eye. Optic neuritis usually affects only one eye and may be a recurring problem with certain diseases such as MS.

Symptoms

Major symptoms are sudden loss of vision (partial or complete), or sudden blurred or "foggy" vision, and pain on movement of the affected eye. Many patients with optic neuritis may lose some of their color vision in the affected eye, with colors appearing subtly washed out compared to the other eye. A study found that 92.2% of patients experienced pain, which actually preceded the visual loss in 39.5% of cases.

Diagnosis

An ophthalmologist, a physician trained in diseases of the eye, will typically make a diagnosis of optic neuritis. A complete visual exam, including a visual acuity test, color vision test, and examination of the retina and optic disc with an ophthalmoscope, will be performed.

Treatment

Visual acuity often returns to normal within 2 - 3 weeks with no treatment.

Corticosteroids given by an IV may speed up recovery but can cause body-wide side effects.

Optic neuritis in demyelinating disease has a favorable prognosis without treatment for an individual attack, but over a period of years significant visual loss is the rule since permanent damage results from recurrent attacks.

Prevention

Regular annual eye exams are critical to maintaining healthy vision. Early treatment of vision problems can prevent permanent optic nerve damage (atrophy).