When the body attacks the eye!

We all know that the air we breathe and the soil we walk on are full of micro organisms like bacteria, virus and fungii.  Though we are surrounded by micro organisms we seldom fall sick. This is because our immune system fights off bacterial and viral infections. Immune system  is a complex network of specialized cells and organs that work together to defend the body against attacks by foreign invaders, such as bacteria and viruses. The immune system can be classified as innate immune system & acquired immune system. The innate  immune system  is more primitive and it employs types of white blood cells called granulocytes and monocytes to destroy harmful substances. The acquired immune system is the part of the immune system that develops as a person grows. It employs antibodies and specialized white blood cells to fight harmful substances.

The body forms antibodies to fight bacteria and virus attacks. Each time a new bacteria or virus attacks us  our body forms a specific antibody to counter it. Sometimes these antibodies mistake our body parts for micro organisms and it starts attacking the body by mistake. This is called auto immune disorders.

Autoimmune diseases can occur in the eyes. When the white outer cover of the eye is attacked by our own antibodies we develop a painful condition called scleritis. When the inner coat of the eye called uvea is attacked the condition is called uveitis.

Uveitis usually presents with redness in the eyes and hence can be mistaken for conjunctivitis or madras eye. As opposed to conjunctivitis delayed treatment can cause permanent blindness.  Uveitis is estimated to be responsible for approximately 10% of the blindness in the United States. The main differentiating factor between uveitis and conjunctivitis is pain which is usually always present in uveitis but is absent in conjunctivitis.

Uveitis can be caused by autoimmune disorders such as rheumatoid arthritis or ankylosing spondylitis, infection, or exposure to toxins. However, in many cases the cause is unknown.

Uveitis can be associated with any of the following:

·         AIDS

·         Ankylosing spondylitis

·         Herpes zoster infection

·         Injury

·         Psoriasis

·         Rheumatoid arthritis

·         Sarcoidosis

·         Syphilis

·         Toxoplasmosis

·         Tuberculosis

Symptoms

·         Blurred vision

·         Dark, floating spots in the vision

·         Eye pain

·         Redness of the eye

·         Sensitivity to light

Treatment

·         Dark glasses to lessen photophobia

·         Eye drops that dilate the pupil to relieve pain

·         Steroid eye drops

·         Uveitis treatment depends on the underlying cause but almost always includes steroids taken by mouth. Additional specialists in infectious disease or autoimmunity may be needed for such diseases as syphilis, tuberculosis, AIDS, sarcoidosis, or Behcet syndrome.

·         If the uveitis is caused by a body-wide infection, treatment may involve antibiotics and powerful anti-inflammatory medicines called corticosteroids.

Expectations (prognosis)

With proper treatment, most attacks of anterior uveitis go away in a few days to weeks. However, relapses are common.

Inflammation related to posterior uveitis may last from months to years and may cause permanent vision damage, even with treatment.

Key Words

Antibody – A special protein produced by the body’s immune system that recognizes and helps fight infectious agents and other foreign substances that invade the body.

Antigen – A foreign substance that triggers the production of antibodies when it is introduced into the body.

Autoimmune disease – A disease that results when the immune system mistakenly attacks the body’s own tissues.

Corticosteroids – Potent anti-inflammatory hormones that are made naturally in the body or synthetically (man-made) for use as drugs. They are also called glucocorticoids. The most commonly prescribed drug of this type is prednisone.

Immunosuppressive drugs – Drugs that suppress the immune response and can be used to treat autoimmune disease. Unfortunately, because these drugs also suppress normal immunity, they leave the body at risk for infection.

Inflammation – A reaction of body tissues to injury or disease, typically marked by five signs: swelling, redness, heat, pain, and loss of function.