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Disease

Retinitis Pigmentosis

 

Definition: Retinitis pigmentosa (RP) is the name given to a group of inherited eye diseases that affect the retina.The damage done to the retina gets worse (progresses) over time. People with this condition have problems with night vision and peripheral vision. 

Causes and Risk Factors: Retinitis pigmentosa causes the degeneration of photoreceptor cells in the retina. Photoreceptor cells capture and process light helping us to see. As these cells degenerate and die, patients experience progressive vision loss.
There are types of photoreceptor cells: rod cells and cone cells. Rod cells are concentrated along the outer perimeter of the retina. Rod cells help us to see images that come into our peripheral or side vision. They also help us to see in dark and dimly lit environments. Cone cells are concentrated in the macula, the center of the retina, and allow us to see fine visual detail in the center of our vision. Cone cells also allow us to perceive color. Together, rods and cones are the cells responsible for converting light into electrical impulses that are transmitted to the brain where “seeing” actually occurs.  The cells controlling night vision (rods) are most likely to be affected. The main sign of the disease is the presence of dark pigmented spots in the retina.  As the disease gets worse, peripheral vision is gradually lost. The condition may eventually lead to blindness, but usually not complete blindness. Signs and symptoms often first appear in childhood, but severe visual problems do not usually develop until early adulthood.
Retinitis pigmentosa commonly runs in families. The disorder can be caused by a number of genetic defects.  It is an uncommon condition affecting about 1 in 4,000 people in the United States.

Signs & Symptoms:

• Vision decreased at night or in reduced light
• Loss of peripheral vision
• Loss of central vision (in advanced cases)

 

Diagnostic Testing: 

• Retinal examination
• Visual acuity
• Slit lamp examination
• Electroretinography (ERG)
• Ultrasound
• Optical Coherence Tomography (OCT)
• Flourescein Angiography (FA)

Treatment: There is no effective treatment for this condition. The use of sunglasses to protect the retina from ultraviolet light may help preserve vision.
Controversial studies have suggested that treatment with antioxidant agents (such as vitamin A palmitate) may delay the disease from getting worse.

Referral to a low vision specialist is very helpful. Patients should make regular visits to an eye care specialist to screen for the development of cataracts or retinal swelling -- both of which can be treated