Optic neuritis is acute inflammation of the optic nerve. Optic nerve is the nerve connecting the eye to the brain. It carries the visual signals from the retina to the brain where it is received and interpreted.
Typical optic neuritis is seen in demyelinating diseases like multiple sclerosis or neuromyelitis optica. Optic neuropathy can also have infectious, autoimmune, ischemic or infiltrative etiology. It is important to differentiate typical optic neuritis from other causes because typical form of optic neuritis has a self limiting course with complete to near complete recovery of vision. Also differentiation becomes important for the purpose of treatment. Multiple sclerosis is a disease that can affect the entire nervous system. It can start with typical optic neuritis. Hence early diagnosis can help early treatment thus preventing the morbidity or suffering from multiple sclerosis.
Typical forms are usually seen in young adults between 20-40 yrs of age
. It is more commonly seen in females. Other forms of optic neuropathy can occur in any age group depending on the cause.
Typical optic neuritis patients usually complaints of sudden painful blurring of vision progressing over the first few days or weeks. After which vision gradually improves. In children it commonly affects both the eyes and is usually seen post vaccination or following some viral infections.
Diagnosis of optic neuropathy can be made by the doctor on examination alone. Investigations are required to differentiate a typical optic neuritis from other causes of optic neuropathy. Few blood investigations along with an MRI of the brain and eye is done at the first attack of optic neuritis
In case of typical optic neuritis steroids can hasten visual recovery and reduce the chances of recurrence. Steroids are injected into the vein for 3 days followed by oral dose for 11 days. This is as per the ONTT, a randomized control trial.
Other forms of optic neuropathy needs to be appropriately treated depending on the cause.
Prognosis is excellent in a patient with typical optic neuritis with near complete recovery of vision. Recurrent episodes can cause permanent damage to the optic nerve called optic atrophy leading to permanent vision loss.
To prevent recurrence the underlying cause of optic neuropathy needs to be treated. In case of infectious neuropathy appropriate and adequate antibiotics can resolve the attack and prevent recurrences. Steroids take care of typical optic neuritis and autoimmune optic neuropathies reducing recurrences. Similarly withdrawal of offending drugs help in toxic optic neuropathies.