OPTIC NEURITIS AND STEM CELL THERAPY

What is optic neuritis?

stem cell bookOptic neuritis is an inflammatory condition in which the myelin sheath of the optic nerve is removed. It is also referred to as optic papillitis. This condition can happen all of a sudden. The optic nerve is the nerve that sends messages from the eyes to the brain. In optic neuritis, the optic nerve loses the fat material, also known as the myelin sheath it. This leads to the slow transmission of impulses.  Patient usually complains of blurry vision, and can’t see colors. He might experience pain, especially during eye movements. This condition is very predominant in people suffering from multiple sclerosis. It might present with severe symptoms, however, most people recover from this inflammatory disease without any treatment. Optic neuritis is one of the symptoms of the relapsing-remitting form of multiple sclerosis.  However, it can also occur in diseases such as diabetes, and when an individual takes some drugs. This disease often resolves by itself, however, it can lead to blindness in severe cases. A lot of research is ongoing in stem cell therapy to treat this disease.

What are the signs and symptoms of optic neuritis?

Optic neuritis has a sudden onset, and it usually affects one eye, however, it can affect the two eyes in children. It occurs suddenly over some hours or days. Symptoms of this disease include;

  1. Eye discomfort: People suffering from this inflammatory condition might experience some pain in the affected eye, that becomes worse when the person moves the eye. The pain presents a dull pain behind the eye.
  2. Loss of vision in the affected eye: People affected by optic neuritis often have some sort of impairment in the affected eye. The severity of this impairment varies from people to people. Some people experience a transient decrease in vision, while it remains permanent in some people. This vision loss has a fast onset. It can develop rapidly in some hours, days, and weeks to months.
  3. Loss of vision field: Patients might lose their peripheral vision. However, this can occur in any pattern.
  4. Problems with color vision: Patients suffering from this condition often have a reduced perception of colors. They might complain that colors look less vibrant than they should look.
  5. Flashing lights: Persons affected by this disease often present with flashing lights when they move their eyes.
  6. Patients might also complain of having a hole in the center of their vision.
  7. Total blindness: Some patients experience total blindness in the affected eye. However, this is a rare occurrence.

In most cases, optic neuritis affects one eye in adults, however, it commonly affects the two eyes in children. Some patients do recover from this disease in just weeks without even taking any medication, while others won’t recover completely until after months and even years. Some few persons never recover from this disease; they proceed to lose the vision in the affected eye completely. Some other people might recover partially, but still have problems seeing colors, especially at night. Optic neuritis is one of the symptoms of multiple sclerosis. Optic neuritis caused by multiple sclerosis can be triggered by some factors, such as heat. Patients usually present with symptoms after an exercise or fever.

 

What are the causes of optic neuritis?

The actual cause of optic neuritis is not known. However, it has been proved to a large extent that this disease is as a result of an autoimmune problem. This is when the immune system fails to recognize the myelin sheath as a body tissue. This leads to the T-cells and other components of the immune system, attacking the myelin sheath of the nerves. The function of the myelin sheath is to increase the speed at which signals and impulses are passed from one nerve cell to another. The myelin sheath is regularly interrupted by the nodes of Ranvier; this leads to salutatory conduction. It’s a fast mode of conducting impulses in which they jump from one node to another, through the myelin sheath. This feature becomes partially lost when the myelin sheath is injured or damaged. Below are some of the causes of optic neuritis;

  1. Multiple sclerosis: Multiple sclerosis is an autoimmune disease in which the myelin sheath of the nerves is attacked by the T-cells of the body immune system. This condition affects the nerve cells of the central nervous system, which includes the brain and the spinal cord. The chances of having optic neuritis after suffering from multiple sclerosis are about fifty percent in a lifetime. The risk increases if the Magnetic resonance imaging(MRI) machine records lesions in the brain.
  2. Infections: There are some infections that have been associated with the development of this disease. Some of this infectious disease include bacterial infections such as Lyme disease caused by Borrelia burgdoferi, syphilis, and viral diseases such as mumps and herpes.
  3. Neuromyelitis Optica: This is the condition in which there is inflammation of the optic nerve and spinal cord. This condition shares some similarities with multiple sclerosis, however, neuromyelitis optica seldom do damage to the neurons of the brain, unlike multiple sclerosis that does a lot of damage to the nerve cells of the brain and the spinal cord.
  4. Medications: There are some drugs that could lead to optic neuritis. Some of the drugs that have been implicated are quinine drugs and antibiotics.
  5. Others: Some other diseases have also been linked to the development of this disease. Some of this disease include sarcoidosis and lupus erythematosus disease. These diseases can cause optic neuritis

 

How Is Optic Neuritis Currently Treated?

Optic neuritis usually resolves on its own. However, steroid drugs can be used to reduce, because of their anti-inflammatory properties, to reduce the inflammation of the nerve cells. However, steroid drugs have some side effects when used for a long time. Some of the side effects include a rapid and excessive gain of weight, gastrointestinal problems and so on. When steroid therapy fails, plasma exchange therapy can be used to restore the vision of this kind of patients.

 

Stem Cell Therapy Of Optic Neuritis

Stem cells are cells that have some special abilities, such as self-regeneration, immune modulation, and tissue repair. Stem cells can be gotten from different sources, however, mesenchymal stem cells have proved to be one of the most effective in the treatment of optic neuritis. These cells have the ability to repair and replace the damaged myelin sheaths. They also have the ability to reduce inflammatory reactions, thereby, slowing down the immune attack on the myelin sheath of the nerve cells, and even stopping it entirely.

References

Multiple Sclerosis Risk After Optic Neuritis. (2008). Archives of Neurology, 65(6).

Neurologic Impairment 10 Years After Optic Neuritis. (2004). Archives of Neurology, 61(9), pp.1386-1389.

Sergott, R. (2011). Directional diffusivity changes in the optic nerve and optic radiation in optic neuritis. Yearbook of Ophthalmology, 2011, p.196.

Zheng, X., Huang, Y., Wang, Z., Yan, H., Pan, S. and Wang, H. (2011). Presumed cytomegalovirus-associated retrobulbar optic neuritis in a patient after allogeneic stem cell transplantation. Transplant Infectious Disease, 14(2), pp.177-179.