What is Optic Neuritis?

Optic neuritis is an inflammation of the optic nerve, the structure that connects the eye to the brain. 
It can cause a sudden reduction of vision in the affected eye.

The optic nerve is composed of a nerve extension (axon) that originates in the retina of each eye.

The optic nerve  carries  the visual information from the retina to the neurons in the brainstem, where the signal is routed to the area of ​​the brain that processes the vision (occipital cortex).

 

Classification of optic neuritis

There are four types of optic neuritis:

1.  Retrobulbar neuritis or inflammation of the optic nerve in the back of the eye is usually caused by multiple sclerosis . This disease is characterized by total or partial loss of the myelin sheath that involves the nerves. 
2. Papillitis or anterior optic neuritis  : inflammation of the optic disc in the front can be caused by multiple sclerosis. 
3. Perineuritis is the inflammation of the sheath of the optic nerve, it saves the optic nerve itself. 
Patients are usually elderly and loss of vision is mild to moderate. 
Perineuritis is caused by infectious or inflammatory diseases, such as syphilisor sarcoidosis. 
4. Neuroretinitis. Signs also include swelling of the optic nerve and macula. 
The exudate (inflammatory fluid) that forms around the macula has the appearance of a star. 
Perineuritis and neuroretinitis are not related to multiple sclerosis.

 

Causes of neurite optic

1. Acute demyelination
is the most frequent cause of optic neuritis in regions where multiple sclerosis is most frequent (Caucasian populations and high latitudes).

2. Ischemic Optic Neuropathy
Previous ischemic optic neuritis (NSAID) derives from ischemia in the prelaminar, laminar, or retrolaminar portion of the optic nerve. 
There are two types of NOIA:

Non-arteritic form
Risk factors are:

Arteritic form
Among the risk factors are:

  • Horton’s disease or giant cell arteritis, is a vascular disorder that affects the medium and large caliber arteries.
  • Systemic lupus erythematosus ,
  • Rheumatoid arthritis ,
  • Poliarterite nodosa.

Among the symptoms of anterior ischemic optic neuritis are:

  • Narrowing of the visual field. It is possible to lose sight only from the top of the visual field or only from the bottom while maintaining the center.
  • Distortion in the central region in the form of a wedge or arch.
  • Loss of contrast sensitivity.

3. Autoimmune optic neuritis, the causes can be:

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

4. Optic neuritis parainfecciosa,  can be a consequence of:

  • Disseminated acute encephalomyelitis ,
  • Post infection ,
  • Post-vaccination,
  • Neuroretinite.

A viral infection, such as:

  1. Measles
  2. Mumps
  3. Rubella
  4. Pertussis
  5. Glandular fever

5. Interstitial or infectious optic neuritis  is a type of  optic nerve meningitiscaused by one of the following infectious processes:

  • Tuberculosis ,
  • Syphilis,
  • Lyme disease ,
  • Cat Scratch Disease,
  • Herpes zoster,
  • Cryptococcal meningitis,
  • Toxoplasmosis ,
  • Viral neuritis (a rare complication of chicken pox ),
  • Periorbital and paranasal sinus infections (orbital cellulitis, severe suppurative sinusitis ).

6. Toxic and metabolic neuritis 

Nutritional deficiency

  1. Severe vitamin B12 deficiency ;
  2. Vitamin B1 deficiency in alcoholics.

Neural frontal optic caused by medications and toxins, for example:

  • Amiodarone,
  • Etambutol,
  • Isoniazid,
  • Poisoning with methanol,
  • Alcohol ,
  • Glutamate,
  • Quinine,
  • Ambliopia for tobacco – methanol.

Hereditary optic neuropathy

  1. The hereditary optic neuropathy Leber is a genetic disease that affects the optic nerve, is usually bilateral. 
    Leber’s hereditary optic neuropathy is a rare disease that can lead to loss of central vision. 
    It usually affects men (80/90% of cases) between 15 and 35 years, but symptoms can be seen at any age, in men or women.
  2. Autosomal dominant optic atrophy is a genetic disease that causes the progressive loss of a type of retinal cell that transmits images from the eye to the brain. 
    The consequences are a progressive loss of vision, blindness, and a change in color vision. Autosomal dominant optic atrophy affects both sexes between 4 and 6 years of age, and symptoms worsen with growth.

8. Post-traumatic optic neuritis is caused by direct trauma or  cranial trauma .

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

 

Symptoms of Optic Neuritis

Neurite optics

Optic neuritis is usually unilateral (affects only one eye), although it may be bilateral. 
Symptoms of optic neuritis include:

1. Pain . Most people who develop optic neuritis have headache and eye pain that is aggravated by the movement of the eye. Generally, pain associated with optic neuritis reaches maximum intensity within a few days. 
2. Loss of vision . The extent of vision loss related to optic neuritis is variable. 
Most people have a rapid and sharp reduction of vision from far and near. 
Loss of vision may be permanent in some cases. 
Reduced visual field : There may be a blind or black dot in the center of the visual field, or only at the bottom or top. 
3. vision and color loss. Optic neuritis often affects the perception of color. 
It is possible to notice that the colors of objects, especially red, appear temporarily “faded” or less bright than normal. 
4. Lightning . Some people with optic neuritis report seeing flashing or shaky lights. 

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

 

Diagnosis of neurite optic

The diagnosis of acute demyelinating optic neuritis is made by consulting the ophthalmologist. 
If the clinical picture is typical, the initial assessment includes:

Ophthalmic examination:

  • Visual acuity test,
  • Contrast sensitivity,
  • Visual field test,
  • The ocular fundus examination in which the papilla (optic nerve head) is swollen,
  • Test of pupil reaction to light.

Diagnosis of anterior ischemic optic neuritis

1. The evoked visual or PEV test (a test that measures how long the brain needs to receive and process the visual stimuli) shows an increase in completion time and a decrease in amplitude; 
2. Ocular fluorescein angiography shows a decrease in blood flow to the optic disc.

Laboratory tests, diagnostic imaging and general tests:

  • Visual response test : to measure the possible delay in conduction of the optical impulses to the brain due to damage to the optic nerve.
  • The  MRI of the brain can be used to provide information about the likelihood of developing multiple sclerosis (MS). 
    Some studies show that the contrast sensitivity test may give information similar to magnetic resonance imaging .

If there are atypical characteristics, the analysis varies according to the clinical picture and may include:

  • Blood tests – complete blood count , erythrocyte sedimentation rate (ESR), autoantibodies and serology for syphilis.
  • Immunoglobulin G test for optic neuromyelitis.
  • Chest X -ray for suspected sarcoidosis, tuberculosis or malignant disease.
  • Computed tomography or magnetic resonance imaging of the brain and orbits.
  • Lumbar puncture – to exclude central nervous system infection or inflammatory optic neuritis ( cerebrospinal fluid is examined  for immunoglobulins, oligoclonal bands, and infections ).

 

Differential diagnosis

The physician should exclude the following diseases: 
1. Scleritis posterior 
2. Maculopathy – macular degeneration
3. Retinopathy.

 

Treatment for Optic Neuritis

The treatment of optic neuritis has changed in recent years due to a series of studies called “Optic Neuritis Treatment Trials” (ONTT). 
In these studies, people with optic neuritis were randomized to treatment based  on cortisone ,  cortisone (oral) or placebo injections . 
Then they were evaluated for several years. 
From these studies, the researchers noted that cortisone treatment had little effect on the final visual outcome in patients with optic neuritis. 
However, patients treated with intravenous steroids had fewer recurrences of neurite optic attacks than patients treated with oral cortisone alone.
Indeed, those treated with oral cortisone alone had a higher risk of repeat neurite-optic attacks than those treated with placebo . 
Most importantly, patients initially treated with intravenous steroids had about half the risk of developing multiple sclerosis within the next two years compared to patients taking oral cortisone or placebo.

In patients treated with steroid injections (followed by oral therapy), 7.5 percent developed multiple sclerosis within the next two years, compared with about 16 percent of the other groups. 
As a result of “ONTT” studies, opticians now treat patients with a combination of cortisone injections and oral corticosteroids or accompany the disease without a prescription of a treatment. 
The use of oral steroids alone is not recommended. 
For patients undergoing therapy, treatment usually includes three days of intravenous steroids, followed by about 11 days of oral glucocorticoids.

Natural Remedies for Optic Neuritis

Diet and nutrition
According to hygienism and  naturopathy , diseases that cause optic neuritis can be treated:

  • By changing the diet ,
  • Without taking medications,
  • With an outdoor and non-sedentary lifestyle,
  • Performing cold frictions on the body, patches , etc.

The recommended food is based on possibly raw or cooked foods at not too high temperatures:

  • Fruits, especially seasonal,
  • Vegetables, especially green leaves,
  • Seeds (sunflower, sesame, chia, pumpkin, etc.),
  • Nuts, hazelnuts and almonds,
  • Legumes,
  • Potatoes.

In this way, the blood becomes pure, the digestion is fast and there is no putrefaction or intestinal fermentation. 
According to natural hygiene, fasting is an excellent treatment for optic neuritis if there are no contraindications because:

  • Strengthens the immune system,
  • It has an anti-inflammatory effect,
  • Helps fight tumors (if they are not at an advanced stage).

According to the blood type diet , diseases are caused by some foods. 
Depending on the type of blood, there are food granted and others prohibited. 
Some foods are harmful to everyone and among them are:

  • Cereals with gluten ,
  • Milk and dairy products,
  • Pork,
  • Foods fried or smoked,
  • Chewing gum.

A person who has a serious illness should completely avoid harmful foods, while a healthy person can rarely eat them if they do not cause immediate symptoms (such as bowel problems , headaches, etc.). 
As long as the patient has the symptoms, try to exclude some foods from your diet until you find the foods responsible.

 

How long does optic neuritis last? Recovery time and prognosis

If a patient does not suffer from systemic diseases, the neuritis heals spontaneously  (passes alone) and the patient regains much of the sight within six months after the onset of the disease 
However, about 25 percent have a recurrence of optic neuritis in the affected eye, and about 17 percent develop optic neuritis in the other eye in 10 years.

If magnetic resonance imaging shows white patches indicating myelin damage in nerve fibers, there is a 56 percent chance of developing multiple sclerosis within 10 years. 
Even if the results are normal, a person with optic neuritis has a 22% chance of developing multiple sclerosis.

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