Optic neuritis

What is optic neuritis?
Optic neuritis (neuritis nervi optici) is an inflammation of the optic nerve, the structure that connects the eye to the brain.
It can lead to a sudden decrease in the vision of the affected eye.
The optic nerve consists of a nerve extension (axon) that originates from the retina of each eye.
The optic nerve transports the visual information from the retina to the neurons in the brainstem, where the signals are transmitted to the area of the brain that processes what is seen (occipital cortex).

Classification of optic neuritis

There are four types of optic neuritis:

1. Retrobulbar neuritis or inflammation of the optic nerve at the back of the eye: usually caused by multiple sclerosis.
   This disease is characterized by the partial or complete loss of the myelin sheaths surrounding the nerves.
2. Papillitis or anterior optic neuritis: Inflammation of the optic nerve papilla in the anterior region, may be caused by multiple sclerosis.
3. Perineuritis: Inflammation of the optic nerve sheath, the nerve itself is spared.
   Most patients are elderly and vision loss is mild or moderate.
   Perineuritis is caused by inflammatory diseases or infections, for example syphilis or sarcoidosis.
4. Neuroretinitis: signs also include swelling of the optic nerve and macula.
   The exudation (inflammatory fluid) that forms around the macula has the shape of a star.

Perineuritis and neuroretinitis are not related to multiple sclerosis.

Causes of optic neuritis

1. Acute demyelination
Most cases of optic neuritis occur in areas where multiple sclerosis (MS) is more common (Caucasian population and high latitudes).

2. Ischemic optic neuropathy
Anterior ischemic optic neuritis (AION) stems from ischemia in the prelaminar, laminar or retrolaminar region of the optic nerve.
There are two types of AION:

Non-arteritic form
Risk factors include:

• Hypertension
• Cigarette smoking
• High cholesterol
• Diabetes
• High homocysteine in the blood
• High fibrinogen
• Atherosclerosis
• Sleep apnea

Arteriitic form
Risk factors include:

• Horton’s disease or giant cell arteritis – a vascular disorder that affects the medium and large arteries
• Systemic lupus erythematosus
• Rheumatoid arthritis
• Panarteritis nodosa

Symptoms of anterior ischemic optic neuritis include:

• visual field restriction; vision can be lost only in the upper or lower part of the field of vision and maintained in the middle part;
• central wedge- or arc-shaped distorted vision;
• Decrease in the perception of contrast.

3. Autoimmune optic neuritis, possible causes include:

• Sarcoidosis
• Systemic lupus erythematosus
• Behçet’s disease
• Neuromyelitis optica (Devic syndrome, affects the optic nerves and spinal cord)
• Autoimmune Neuritis
• Recurrent chronic inflammatory neuritis

4. Parainfectious optic neuritis – possible triggers are:

• Encephalomyelitis
• Infection
• Vaccination
• NeuroretinitisViral infections, such as:

1. Measles
2. Mumps
3. Rubella
4. Whooping cough
5. Mononucleosis

5. Infectious or interstitial optic neuritis, it is a form of meningitis of the optic nerve, caused by one of the following inflammatory processes:

• Tuberculosis
• Syphilis
• Lyme disease
• Cat scratch disease
• Herpes zoster
• Cryptococcal meningitis
• Toxoplasmosis
• Viral neuritis (a rare complication of chickenpox)
• Periorbital inflammation and inflammation of the paranasal sinuses (orbital cellulitis, severe purulent sinusitis)

6. Toxic and metabolic neuritis:

Lack of nutrition

1. Severe lack of vitamin B12
2. Vitamin B1 deficiency in alcoholics

Toxic anterior optic neuritis, caused by drugs and toxins, for example:

1. Amiodarone
2. Etambutol
3. Isoniazid
4. Methanoline toxication
5. Alcohol
6. Glutamate
7. Quinine
8. Weak eyesight due to tobacco methanol

7. Hereditary optic neuritis

1. Leber’s hereditary optic neuritis is a genetic disease that affects the optic nerve and usually occurs bilaterally.
   Leber’s hereditary optic neuritis is a rare condition that can lead to loss of central vision.
   It usually affects men (80-90% of cases) between 15 and 35 years of age, but symptoms can occur at any age in both men and women.
2. Autosomal dominant optic atrophy: A genetic disorder that results in progressive loss of a type of retinal cells that transmit the images from the eye to the brain. There is a progressive loss of vision up to blindness and altered color perception. Both sexes are affected between 4 and 6 years, the symptoms increase with growth.

8. Post-traumatic optic neuritis: Caused by direct or traumatic brain injury.

Optic neuritis in children
A viral infection is a common cause.

Symptoms of optic neuritis

Optic neuritis is usually monolateral (only one eye is affected), although it can also occur bilaterally.

Symptoms of optic neuritis include:

1. Pain. Most people who develop optic neuritis have headaches and eye pain that worsen with eye movements. The pain associated with optic nerve inflammation usually reaches its maximum intensity within a few days.
2. Vision loss. The degree of vision loss due to optic neuritis varies.
   Most people experience rapid and significant vision loss when seeing near and far.
   The loss of vision can be permanent in some cases.
3. Reduction of the field of vision. In the middle of the field of vision or only in the upper or lower area, a blind or black spot may be noticeable.
4. Vision and color loss. Optic neuritis often affects color perception.
   It can be observed that the colors of objects, especially red objects, temporarily “fade” or appear less fresh than normal.
5. Lightning. Some people with optic nerve inflammation report flashing or trembling lights.

In 15-20 percent who develop multiple sclerosis, optic neuritis is the first symptom.

Diagnosis of optic neuritis

The diagnosis of acute, demyelinating optic neuritis is established by an examination at the ophthalmologist.
If the clinical picture is typical, the initial evaluation plans include:

Complete ophthalmological examination:

• Visual acuity assessment
• Contrast sensitivity
• Visual field analysis
• Examination of the base of the eye, where a swollen papilla (head of the optic nerve) is recognizable
• Interpupillary response test for light

Diagnosis of anterior ischemic optic neuritis

1. The study of visually evoked potentials, or VEP (a test that measures the time it takes the brain to process visual stimuli), shows an increase in the duration of climax and decrease in amplitude.
2. Fluorescence angiography shows a decrease in blood flow in the optic nerve papilla.

Instrumental investigations:

• Visual reaction test: to detect a possible slowdown in the transmission of visual impulses to the brain due to damage to the optic nerve.
• Magnetic resonance imaging of the brain: may be required to provide information about the likelihood of developing multiple sclerosis (MS).
  Some studies show that examining contrast sensitivity can give similar information to magnetic resonance imaging.
  If there are atypical characteristics, the analyses depend on the clinical picture; These include:
• Blood tests – complete blood count, erythrocyte sedimentation rate (BKS), autoantibodies and serology for syphilis.
• Examination of immunoglobulin G in neuromyelitis optica.
• X-ray of the thorax if sarcoidosis or malignant disease is suspected.
• CT or magnetic resonance imaging of the brain and eye sockets.
• Lumbar puncture – to rule out infection of the central nervous system or inflammatory optic neuritis (examining the cerebrospinal fluid for immunoglobulins, oligoclonal bands and infections).

Differential diagnosis

The doctor must exclude the following diseases:

1. Posterior scleritis
2. Maculopathy – Macular degeneration
3. Retinopathy

Treatment of optic neuritis

The treatment of optic nerve inflammation has changed in recent years due to some studies called “Optic Neuritis Treatment Trials” (ONTT).
In these studies, people with optic nerve inflammation were randomly selected for cortisone-based therapy (steroids) intravenously, orally, or as a placebo.
Then her condition was assessed for years.
In these studies, scientists found that treatment with corticosteroids had little effect on final visual outcomes in patients with optic neuritis.
However, patients treated endovenously with corticosteroids had fewer recurrences of attacks of optic nerve inflammation than patients treated orally with corticosteroids alone.
In fact, those treated with oral corticosteroids had a higher risk of attacks of optic neuritis compared to those treated with placebo.
More importantly, patients initially treated endovenously with corticosteroids had about half the risk of developing multiple sclerosis in the following two years compared to patients treated orally with corticosteroids or placebo.
7.5 percent of those treated intravenously (subsequently orally) developed multiple sclerosis in the following two years, compared with about 16 percent of the other groups.

As a result of the “ONTT” study, ophthalmologists are now treating patients with a combination of intravenous and oral corticosteroids or pursuing the condition without prescribing therapy. The use of oral corticosteroids alone is not recommended.
For patients receiving therapy, treatment is usually three days for intravenous corticosteroids, followed by 11 days for oral corticosteroids.

Natural remedies for optic neuritis

Diet and nutrition
According to the theories of hygienism and naturopathy, the diseases that provoke optic neuritis can be cured by the following measures:

• Nutrition
• Without taking medication
• With a way of life in the fresh air with sufficient physical activity
• Cold abrasions of the body, packs, etc.

The recommended diet is based on foods that are as uncooked as possible or cooked at low temperatures:

• Fruit, preferably seasonal fruit
• Vegetables, especially green leafy vegetables
• Seeds (sunflower, sesame, chia, pumpkin, etc.)
• Walnuts, hazelnuts and almonds
• Pulses
• Potatoes

In this way, the blood becomes pure, digestion is fast and there is no fermentation and rot in the intestine.
According to natural hygiene, fasting is an excellent therapeutic measure for optic neuritis, if there are no contraindications, because:

• it strengthens the immune system,
• it has an anti-inflammatory effect,
• it helps fight tumors (if the stage is not yet advanced).

According to the blood group diet, diseases are provoked by some foods. Depending on the blood group, there are forbidden and permitted foods.
There are also foods that are fundamentally unhealthy, including:

• cereals containing gluten,
• milk and dairy products,
• Pork
• fried and smoked foods,
• Chewing gum.

A patient with a serious illness should completely abandon harmful foods, while a healthy person can eat them moderately if they do not cause immediate symptoms (such as intestinal problems, headaches, etc.).
As long as the patient is experiencing symptoms, some foods should be removed from the diet until the culprits have been found.

How long does optic neuritis last? Recovery times and prognosis

If the patient does not suffer from systemic diseases, neuritis heals spontaneously (on its own) and vision can be largely regained within six months of onset.

Nevertheless:

• about 19 percent have a recurrence of optic neuritis in the affected eye;
• 17 percent develop optic nerve inflammation in the other eye within 10 years.

If the images of an MRI show white spots that indicate myelin damage in the nerve fibers, there is a 56 percent chance that multiple sclerosis will develop within 10 years.
Even if normal results are available, a person with optic nerve inflammation has a 22 percent chance of developing multiple sclerosis.

• Multiple sclerosis: symptoms and complications
• Multiple sclerosis: forms and causes
• Multiple sclerosis: diagnosis and drugs to treat