Optic neuritis is inflammation of the optic nerve [See figure 1]. As the photo demonstrates, the optic nerve becomes swollen and the blood vessels become larger. This inflammation can cause loss of vision because the optic nerve is crucial for vision. It is the structure that carries visual information from the eye to the brain to produce visual images.
Fig. 1: Optic nerve swelling in a patient with optic neuritis.
What are the symptoms of optic neuritis?
The first symptom of optic neuritis in a child is most commonly a rapid, often profound decrease in vision (visual acuity less than 20/400). It can occur in both eyes and it may be worse in one eye than another. Patients may also have headaches and pain with eye movement. Many children with optic neuritis have a history of a fever, flu-like illness, or immunizations 1-2 weeks prior to the onset of the decreased vision.
What causes optic neuritis?
Optic neuritis is thought to be an autoimmune disorder, in which the immune system mistakenly attacks the body’s own optic nerve tissue. The attack of the immune system causes inflammation, swelling and impaired function of the optic nerve. The trigger for this immune reaction may be a viral illness, infection around the optic nerve, multiple sclerosis, or other neurological problems.
How is optic neuritis diagnosed?
A careful history including inquiring about recent illness, fever, neurological symptoms, or recent immunizations is helpful. The Eye MD checks vision (which is usually markedly decreased) and evaluates optic nerve function including the pupil reactions, color vision, and peripheral vision. The Eye MD also examines the optic nerve with ophthalmoscopy for swelling and dilated blood vessels. Other tests performed may include an MRI, a spinal tap (lumbar puncture), and blood tests.
What is the prognosis and treatment for optic neuritis?
Fortunately, most children with optic neuritis recover much of their vision. This usually occurs spontaneously and treatment may not be necessary. Recovery usually begins within a few weeks, and can continue for several months. Intravenous corticosteroids may speed the recovery of vision, but probably do not improve the final visual outcome. Unfortunately, a small percentage of children do not recover vision.
What are the differences between optic neuritis in children and adults?
Both eyes are usually affected in children, while adults usually have only one eye affected. Children with optic neuritis usually have a history of recent illness or immunization and adults do not. Both adults and children have an increased risk of multiple sclerosis if they develop optic neuritis, but children have much less risk.