Your optic nerve is important as it is essential to our sight. The optic nerve’s function is to transmit information that we see and what is formed on our retina (situated at the back of your eye) to the brain. This enables us to see better. In optic neuritis, your optic nerve gets inflamed that leads to blurring of vision. Optic neuritis is also called retrobulbar neuritis. Depending on how inflamed your optic nerve gets, your symptoms may be mild or severe. Optic neuritis occurs at any age but is mostly seen in the third decade. Most cases resolve on their own, but in a few cases, vision may be permanently impaired. Optic neuritis can be caused by a number of causes, including multiple sclerosis (a condition affecting your brain and spinal cord that results in a loss of the protective covering of your nerves).[1]
The types of optic neuritis are as follows.
Typical optic neuritis: The cause is mostly multiple sclerosis but can have other unusual reasons too. It occurs in the ages of 20 to 50 years and is characterized by pain in the eye or moving your eye before actual visual symptoms appear. Your visual loss occurs progressively over days to weeks. It does not require steroids for treatment.
Atypical optic neuritis: the cause may be multiple sclerosis or other causes. It typically occurs before the age of 20 or after the age of 50. The common types of atypical optic neuritis are neuromyelitis optica, Neuroretinitis, chronic recurrent immune optic neuropathy, and autoimmune diseases that affect your optic nerve. The pain usually lasts for more than two weeks. Here, the loss of vision is sudden, occurring in hours or over two weeks. It is dependent on steroids for treatment.
Optic neuritis can occur only in one eye or may affect both your eyes. The symptoms may be sudden or may appear after a few days or weeks. Without treatment, your symptoms can get worse; it is, therefore, essential to contact your ophthalmologist (eye doctor). Following are the symptoms of optic neuritis.
Reduced vision is usually the first and vital symptom
Causes
Though the exact cause of optic neuritis is unclear, it may be caused by the following.
Any condition that causes demyelination (loss of the covering of the nerve) of the optic nerve, which may occur due to an autoimmune disease (a condition in which your own body attacks your cells)
Further episodes of optic neuritis can be prevented by treating the underlying cause. If the cause is an infection like tuberculosis or syphilis, then antibiotics can help treat it. If the cause of optic neuritis is toxins, then withdrawal of the toxin and supplementing vitamins can help. For individuals receiving treatment for tuberculosis and who suffer from optic neuritis, then ethambutol, an antitubercular medicine, will need to be halted. If the cause is multiple sclerosis, then treatment with steroids, intravenous immunoglobulins, immune modulators or plasmapheresis can help in the prevention of optic neuritis.[6]
Optic neuritis is diagnosed based on the medical history of the patient. Excluding other causes that can cause loss of vision are ruled out. An ophthalmologic examination is performed to identify any abnormalities present at the back of the eye. An ophthalmoscope may be used to view the optic nerve and identify any abnormalities with it. Investigations can help rule out the cause of optic neuritis so that the treatment can be decided accordingly. The diagnosis of optic neuritis can be done with the help of the following tests.
Optic Neuritis usually does not require any treatment. The condition resolves by itself in around four to 12 weeks. Around 85% of the times optic neuritis causes permanent vision damage. However, this damage may not necessarily cause grave vision issues. The vision returns once the inflammation reduces.
In severe cases, intravenous corticosteroids may be administered to hasten recovery. However, steroid use may increase the chances of recurrence. The use of oral corticosteroids is contraindicated due to the recurrence rates. Though steroids accelerate recovery, they come with other perils. Side effects of steroids include upset stomach, metallic taste in your mouth, sleep problems, anxiety, irritability, increased levels of glucose, and fungal infections like thrush. Steroids hasten recovery, but research has seen that visual recovery remains the same with or without steroid treatment after a year.
Interferon therapy given as injections can reduce multiple sclerosis from occurring in individuals who already have optic neuritis. It is vital to follow up with your ophthalmologist (eye doctor) to evaluate your eyes and identify early signs of multiple sclerosis. [1,5,6]
Certain home remedies can be followed for optic neuritis, which is stated below.
What to eat & What not to eat when you have optic neuritis
Foods to eat are vegetable juices like carrot, beetroot, and spinach juice. Consuming vitamin B supplements and nutrients like alpha-lipoic acid and omega-3 fatty acids can also help in reducing the inflammation of your nerves and preserve the nerve function.
Foods to avoid are canned meat, canned fish, cereal, tea, coffee, and white bread, which can increase pain during neuritis episodes.[6]
Prognosis
In patients who have a disease which causes optic neuritis, their recovery chances are improved. Individuals with autoimmune diseases have a worse prognosis but may regain their vision in the eye that is affected. In patients with typical optic neuritis, the prognosis is excellent. However, if left untreated, recurrent episodes can cause permanent loss of vision (optic atrophy) due to eventual permanent damage to the optic nerve.[6,7]
Complications
Due to prolonged use of steroids, complications like increased blood sugar, increase in weight, and problems in your bone may occur. This can lead to effects on your entire body. The complication of optic neuritis is optic atrophy which results in the optic nerve becoming permanently thin. Atrophy of the optic nerve will further cause visual field loss, reduced visual acuity or both.[6]
Decoding The Visual Pathway: Dr. Mandeep Singh Basu, Director of Dr. Basu Eye Hospital, examines the optic nerve's functions and how it connects our eyes to our brains.
