Optical Neuritis

Optic neuritis is a visual disturbance due to inflammation of the eye nerve (optic nerve). This condition that often occurs in patients with multiple sclerosis is characterized by blurry vision in one eye and pain in the eye

The function of the optic nerve is to carry light signals from the eyes to the brain so that a person can see. If the optic nerve becomes inflamed, infected, or damaged, the sufferer cannot see clearly.

Optic neuritis can occur in adults or children, but is most common in women aged 20-40 years. Optic neuritis usually only affects one eye, but in some cases it can also occur in both eyes.

Causes of Optic Neuritis

The exact cause of optic neuritis is not known with certainty. However, there are allegations that inflammation and damage to the optic nerve are caused by autoimmune disorders, which is a condition when the immune system or the body's immune system attacks the body's own cells.

In optic neuritis, the body's immune system attacks the optic nerve membrane called myelin. When myelin is damaged, nerve signals from the eye cannot be sent properly to the brain. This causes the sufferer to experience visual disturbances.

Autoimmune diseases associated with optic neuritis include:

• Multiple sclerosis

  This disease causes the immune system to attack the myelin membranes in the brain and spinal cord. Not only sufferers of multiple sclerosis are at risk for optic neuritis, people with optic neuritis are also at risk of developing multiple sclerosis.

• Neuromyelitis optica

  Neuromyelitis optica causes inflammation of the optic nerve and spinal cord. Although similar to multiple sclerosis, this disease does not cause nerve damage to the brain like multiple sclerosis.

In addition to these two autoimmune diseases, there are several other factors that are also at risk of causing optic neuritis, namely:

• Use of quinine pills
• Bacterial infections (e.g. syphilis and Lyme disease) or viral infections (e.g. measles, herpes and mumps)
• Other diseases, such as sarcoidosis, lupus, arteritic optic neuropathy, diabetes, glaucoma, and vitamin B12 deficiency

Symptoms of Optic Neuritis

Optic neuritis is characterized by visual disturbances, such as:

• Blurred vision in one eye
• The field of vision is narrowed or peripheral vision is not clearly visible
• Some colors look dimmer than
• Pain when moving the eye
• You see a flash of light in your eyes

In rare cases, visual disturbances can also lead to blindness.

When to see a doctor

Visibility is a serious condition. Consult a doctor if you experience symptoms of optic neuritis as mentioned above, especially if accompanied by the following complaints:

• Pain and blurred vision getting worse
• Symptoms do not improve after treatment
• Tingling or numbness in arms and legs

Diagnosis of Optic Neuritis

As a first step, the doctor will ask about the symptoms experienced by the patient and conduct an examination of the patient's eyes. Some of the eye examinations performed by the doctor are:

Visual acuity check

In this examination, the doctor will ask the patient to see and mention the numbers or alphabet that are placed at a certain distance. This test aims to measure the patient's visual acuity.

Visual field check

Visual field test can help doctors determine the patient's eye ability to see objects that are at the edge of the field of view. This test can be done by various methods, either manually or with the help of special tools.

Pupil reaction test to light

In this test, the doctor will shine a flashlight in the eye to see how the pupil responds to bright light. The pupil of a patient with optic neuritis does not shrink as small as the pupil of a he althy eye when exposed to bright light.

Ophthalmoscopy

Ophthalmoscopy examination aims to examine the optic nerve plate. If the plate is swollen, the patient may have optic neuritis.

Ophthalmoscopy uses a special instrument called an ophthalmoscope. The ophthalmoscope will help the ophthalmologist to illuminate the eye with light and see the structures inside the patient's eyeball.

The ophthalmologist may also perform an optical coherence tomography (OCT) examination to check the thickness of the retinal nerve fibers and a visual evoked response test to assess the speed of electrical flow from the optic nerve. Nerve fibers in patients with optic neuritis are thinner than normal people and the flow of electricity tends to slow down.

In addition to the above examination, there are other tests that can be done to determine the risk factors for optic neuritis, namely:

• Blood test, to check for the possibility of neuromyelitis optica in patients with optic neuritis, by detecting antibodies in the blood
• An MRI scan, to determine the area of damage to the brain that causes multiple sclerosis

Optical Neuritis Treatment

Optic neuritis usually goes away on its own within 4–12 weeks without any specific treatment. However, depending on the patient's condition, the ophthalmologist can provide certain medications to help speed up healing, including:

• Corticosteroids

  Doctors can inject high doses of corticosteroid drugs to treat optic neuritis while slowing and reducing the risk of developing multiple sclerosis.

• Injectable immunoglobulin (IVIG)

  Another treatment for optic neuritis is injectable immunoglobulin (IVIG). This treatment is usually given to patients with optic neuritis who are already severe and can no longer be treated by corticosteroids

• Vitamin B12

  Patients with optic neuritis due to vitamin B12 deficiency can be treated with vitamin B12 injections.

In cases of optic neuritis triggered by another condition, such as diabetes, the doctor will treat the condition.

The patient's vision generally returns to normal within 12 months. Although vision has returned to normal, visual disturbances due to optic neuritis may recur, including in patients without autoimmune disorders. However, it is less likely than people with multiple sclerosis or neuromyelitis optica.

Optical neuritis complications

Complications that can occur due to optic neuritis include:

• Permanent optic nerve damage resulting in blindness
• Risk of deep vein thrombosis (DVT), pulmonary embolism, and urinary tract infection, in patients with optic neuritis due to neuromyelitis optica
• Complications due to side effects of treatment, for example, decreased body resistance due to corticosteroids so that patients are susceptible to infection

Optical Neuritis Prevention

It is difficult to prevent optic neuritis, as this condition is an autoimmune disease. Therefore, to maintain eye he alth and vision, do regular check-ups with a doctor.

People under 40 years old are recommended to have their eyes checked every 2 years. Meanwhile, people over the age of 40 need to have regular eye exams every 1-2 years.

As previously mentioned, people with optic neuritis are also at risk for multiple sclerosis. Therefore, patients with optic neuritis are usually advised to receive interferon injections and routine control to prevent multiple sclerosis.