Retinitis pigmentosa

Alternative names

RP

Definition

Retinitis pigmentosa is a progressive degeneration of the retina (part of the eye) which affects night vision and peripheral vision.

Causes, incidence, and risk factors

Retinitis pigmentosa commonly runs in families. The disorder can be caused by defects in a number of different genes which have recently been identified.

The cells controlling night vision, called rods, are most likely to be affected. However, in some cases, retinal cone cells are most damaged. The hallmark of the disease is the presence of dark pigmented spots in the retina.

As the disease progresses, peripheral vision is greadually 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.

The main risk factor is a family history of retinitis pigmentosa. It is an uncommon condition affecting about 1 in 4,000 people in the U.S.

Symptoms

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

Signs and tests

Tests determine the integrity of the retina:

• visual acuity
  
• Refraction test
  
• Color defectiveness determination
  
• Pupillary reflex response
  
• Slit lamp examination
  
• Intraocular pressure determination
  
• Retinal examination by ophthalmoscopy
  
• Ultrasound of the eye
  
• Retinal photography
  
• Fluorescein angiography
  
• Electroretinogram (a record of the action currents of the retina produced by visual stimuli)
  

Treatment

There is no effective treatment for this condition. The use of sunglasses to protect the retina from ultraviolet light may have a vision-preserving effect.

Though controversial, recent studies have indicated that treatment with antioxidant agents (such as palmitate) may delay the progression of this disease.