Optical neuritis is the inflammation and demyelination of one or both eyes. It can be of three types, based on the part of eye, it affects- Papilitis, Neuroretinisis and RetroBulbar Neuritis. Papilitis includes inflammation of the optic disc. Neuroretinisis refers to combined inflammation involving optic disc and retina. Reterobulbar neuritis involves inflammation of the optical nerve. This type of neuritis is usually associated with viral diseases like cat scratch fever, syphilis etc.
Optic Neuritis can cause temporary or permanent visual loss. In most cases, optic neuritis is due to auto immune disorders but it can also be due to other infections. Onlymyhealth editorial team spoke to Soveeta Rath, Consultant, Department Of Pediatric ophthalmology, Strabismus And Neuro Ophthalmology, Dr. Shroff S Charity Eye Hospital Daryaganj, to know about the symptoms, causes and treatment of optic neuritis.
Optic neuritis symptoms
Most of the symptoms arise within few weeks. For some patients, it might start as pain in the eyes. This might precede to visual loss as symptoms start to show. Here are the main symptoms of optic neuritis:
1. Blurred vision
A lot of people suffering from neuritis suffer from blurred vision. This happens because due to inflammation, our eyes might get cloudy and our brain is unable to form a clear image. A person also might experience certain blind spots in their vision.
Pain in the eyes is one of the major initial symptoms. The pain might not be excruciating but it can be severe in few cases.Most people experience pain in movement of eyes. One should visit a doctor and not ignore pain in the eyes. Pain in the eyes might not be something worrisome but it should not be ignored.
3. Inability to distinguish certain colors
As the inflammation increases, a person might start to feel difficulty in differentiating between various colors. This sort of impairment also depends on the part of eye that is affected.
Any infection in eyes can also lead to headaches. One should not panic because headaches can also be due various other underlying causes but you must visit a doctor for right diagnosis.
5. Partial loss of vision
As discussed above we know that there are symptoms like pain and blurred vision. For some patients they might start to experience partial blindness at first due to optical neuritis. This can also precede to complete loss of vision if you do not go right treatment.
Optic neuritis causes
The exact cause of optic neuritis is unknown. It is said to grow when the immune system falsely targets the material covering your optic nerve, which results in inflammation and damage to the myelin. The potential causes of optic neuritis are:
1. Multiple Sclerosis
Multiple sclerosis and optical neuritis both are autoimmune diseases. If a person suffers from any ony one of these diseases, the chances of suffering from other disease increase significantly. The lesions in the myelin sheath can extend to the optic nerve and vice versa.
2. Neuromyelitis optica
It is a rare autoimmune disease which attacks our spinal chord and optic nerves. It is much more severe than Multiple sclerosis. Patients suffering from this auto immune disease end up with minimal recovery.
3. Myelin oligodendrocyte glycoprotein (MOG) antibody disorder
It is a rare, antibody-mediated demyelinating disorder which causes inflammation the central nervous system. It is also very severe but recovery rates are better than neuromyelitis.
Optic neuritis treatment
Optic neuritis more than often gets better on its own. In few cases, steroid medications are used to reduce inflammation in the optic nerve. Steroid treatments usually given by vein (intravenously). Intravenous steroid therapy makes the vision recovery faster, but it doesn’t affect the amount of vision one will recover for typical optic neuritis. Also, it is not possible to give this treatment to all patients because it has a lot of side effects. Some side effects of steroid treatment may include weight gain, facial flushing, mood swings, insomnia, and an upset stomach. Some studies also suggest that Plasma exchange therapy might also help in optic neuritis recovery but it is still not proven.
Optic neuritis is easily distinguishable from other diseases targeting the optic nerve. Unusual types of this disease and various optic nerve diseases require special treatment. For patients at high risk of developing multiple sclerosis, immune prophylaxis with beta-interferon or glatiramer acetate is usually recommended.
Typical optic neuritis is a critical visual disturbance lacking any clear diagnostic proofs on ocular examination. It is known to affect young, healthy individuals. The cause is an autoimmune reaction against the optic nerve. Optic neuritis might be the initial onset of multiple sclerosis. Nowadays it is more and more used in clinical trials as a model for multiple sclerosis relapses, as visual function is easier to measure and, in particular, as changes in the retinal nerve fiber layer can be envisioned in depth with optical coherence tomography. The optic nerve thus, can be used as an opening to the brain.