Inherited degenerative eye disease with severe vision impairment due to degeneration of rod photoreceptor cells in retina.Encyclopedia Entry for Retinitis Pigmentosa :Retinitis pigmentosa. Retinitis pigmentosa can run in families. The disorder can be caused by several genetic defects. The cells controlling night vision (rods) are most likely to be affected. However, in some cases, retinal cone cells are damaged the most. The main sign of the disease is the presence of dark deposits in the retina. The main risk factor is a family history of retinitis pigmentosa. It is a rare condition affecting about 1 in 4,000 people in the United States.Symptoms often first appear in childhood. However, severe vision problems do not often develop before early adulthood. Decreased vision at night or in low light. Early signs may include having a harder time moving around in the dark. Loss of side (peripheral) vision, causing 'tunnel vision.' Loss of central vision (in advanced cases). This will affect the ability to read.Tests to evaluate the retina: Color vision Exam of the retina by ophthalmoscopy after the pupils have been dilated Fluorescein angiography Intraocular pressure Measurement of the electrical activity in the retina ( electroretinogram ) Pupil reflex response Refraction test Retinal photography Side vision test (visual field test) Slit lamp examination Visual acuity.There is no effective treatment for this condition. Wearing sunglasses to protect the retina from ultraviolet light may help preserve vision. Some studies suggest that treatment with antioxidants (such as high doses of vitamin A palmitate) may slow the disease. However, taking high doses of vitamin A can cause serious liver problems. The benefit of treatment has to be weighed against risks to the liver. Clinical trials are in progress to assess new treatments for retinitis pigmentosa, including the use of DHA, which is an omega-3 fatty acid. Other treatments, such as microchip implants into the retina that act like a microscopic video camera, are in the early stages of development. These treatments may be useful for treating blindness associated with RP and other serious eye conditions. A vision specialist can help you adapt to vision loss. Make regular visits to an eye care specialist, who can detect cataracts or retinal swelling. Both of these problems can be treated.The disorder will continue to progress slowly. Complete blindness is uncommon.Peripheral and central loss of vision will occur over time. People with retinitis pigmentosa often develop cataracts at an early age. They may also develop swelling of the retina (macular edema). Cataracts can be removed if they contribute to vision loss.Contact your health care provider if you have problems with night vision or you develop other symptoms of this disorder.Genetic counseling and testing may help determine whether your children are at risk for this disease.RP; Vision loss - RP; Night vision loss - RP; Rod Cone dystrophy; Peripheral vision loss - RP; Night blindness.Eye Eye Slit-lamp exam Slit-lamp exam.Cukras CA, Zein WM, Caruso RC, Sieving PA. Progressive and 'stationary' inherited retinal degenerations.