Retinitis Pigmentosa

Retinitis pigmentosa (RP) refers to a group of inherited diseases that lead to slow and progressive retinal degeneration that causes damage to the important cells of the retina, the rods and the cones.

People diagnosed with RP usually experience night blindness early on, and later may develop progressive and gradual reduction in their vision and field of view. Many people with RP do not become legally blind until their 40s or 50s and retain some sight all their lives. Others go completely blind from RP, in some cases as early as childhood. Progression of RP is different in each case.

The diagnosis of retinitis pigmentosa relies upon documentation of progressive loss in photoreceptor cell function by electroretinography (ERG) and visual field testing.

The mode of inheritance of RP is determined by family history. RP can be inherited in an autosomal dominant, autosomal recessive, or X-linked manner. X-linked RP can be either recessive, affecting primarily only males, or dominant, affecting both males and females, although males are usually more mildly affected.

Genetic counseling depends on an accurate diagnosis, determination of the mode of inheritance in each family, and results of molecular genetic testing.

The signs of RP are seen in a variety of diseases, so the differential of this sign alone is broad.

      • RP combined with deafness (congenital or progressive) is called Usher syndrome.
      • RP combined with opthalmoplegia, dysphagia, ataxia, and cardiac conduction defects is seen in the mitochondrial DNA disorder, Kearns-Sayre syndrome (aka Ragged Red Fiber Myopathy)
      • RP combined with retardation, peripheral neuropathy, acanthotic (spiked) RBCs, ataxia, steatorrhea, in absence of VLDL is seen in abetalipoproteinemia.
      • Other conditions include neurosyphilis, toxoplasmosis and Refsum’s disease.

Treatment:

      • There is no effective treatment for this condition at this time.
      • Wearing sunglasses to protect the retina from ultraviolet light may help preserve vision.
      • Some studies have suggested that treatment with antioxidants (such as high doses of vitamin A palmitate) may slow the disease in some patients. However, high doses of vitamin A can lead to serious liver damage. Hence, the medication has to be taken on the advice of an ophthalmologist and under the care of a general or a specialist physician, with repeated tests to check liver function. When considering the treatment, both from an ophthalmologists’ and the patients’ perspective, the benefit of treatment has to be weighed against risks of liver damage.
      • Clinical trials are on to investigate new treatments for retinitis pigmentosa, including the omega-3 fatty acid, DHA, etc.
      • Microchip implants that go inside the retina and act like a microscopic video camera are available in some countries. In others, they are in the early stages of development for treating blindness associated with this and other serious eye conditions.
      • It can help to see a low-vision specialist, who can help you adapt to vision loss.
      • It is recommended to make regular visits (annual if possible) to an eye care specialist. Patients can develop a cataract or some retinal swelling – which can cause some amount of visual impairment and can be treated.

Other forms of treatment:

      • Ayurveda: There are a lot of claims from various institutions in the country regarding “cure” for RP. Till date, there is no confirmation about the efficacy of such treatments. Medicine requires hard facts. What we have so far are just anecdotal references to someone being cured for their disease on being treated. There is no confirmatory evidence published, nor are most of these institutions willing to discuss about their treatment and success with us. Until we get proof enough that satisfies the medical world that these treatments work, we will continue to consider that there is no validity to the claims so far.
      • Acupuncture:There are reports in the country that acupuncture has demonstrated success in treating or controlling the progression of RP. Until now, we do not have any evidence that such treatment works in the way it is advertised. Retina India is in discussion with some of the centers in the U.S. who are working in the field of acupuncture to see if it has shown any benefit; if so, we will be collaborating with them for a clinical trial in India with Indian patients to prove whether it works or does not work. There is an on-going clinical trial in the United States that is trying to evaluate it. (link)