Inherited and Genetic Retinal Diseases

What are inherited or genetic diseases?

h-exam2.jpgInherited or genetic diseases are diseases that result from abnormalities in our DNA. These abnormalities in the DNA may be inherited from parents or be randomly acquired. When DNA is defective it may be unable to produce important proteins that are necessary for proper functioning or it may produce abnormal substances that cause more harm than good.

What are some examples of genetic retinal diseases?

There are several genetic defects that give rise to a wide range of retinal diseases – some of which we are only beginning to understand and others that we have not yet discovered. The following is a small list of some inherited or genetic retinal diseases.

  • Macular degeneration
  • Retinitis Pigmentosa (several types)
  • Stargardt’s Disease
  • Fundus Flavimaculatus
  • Leber’s Congenital Amaurosis
  • Doyne Honeycomb Dystrophy
  • Bardet Biedl Syndrome
  • Stickler Disease
  • Wagner Disease
  • Goldman-Favretear
  • North Carolina Macular Dystrophy
  • Vitelliform Macular Dystrophy
  • Best Dystrophy
  • Pattern Dystrophies
  • Choroideremia
  • Familial Fleck Retina
  • Gyrate Atrophy
  • Congenital Stationary night blindness
  • Cone disease
  • Cone-Rod disease
  • Congenital Stationary Night Blindness
  • Achromatopsia
  • Dominant drusen
  • Refsum disease
  • Batten disease
  • Bassen-Kornzweig

How are inherited/genetic retinal diseases diagnosed?

A complete family and medical history as well as a comprehensive dilated exam are important first steps in diagnosing inherited or genetic retinal diseases. However some of these conditions may present with a normal retinal exam despite symptoms. Hence, further testing in the office is important to help make a correct diagnosis. Depending on the disease suspected, testing may include optical coherence tomography (OCT), fundus photography, fundus autofluorescence, indocyanine green angiography (ICG), fluorescein angiography (FA), visual field testing, color vision testing, dark adaptometry, and an electroretinogram (ERG), or electroculogram (EOG). You may learn more about these particular tests under our diagnostic testing section. Furthermore, genetic testing has come a long way in the past several years and many of the defective genes that give rise to these conditions have been identified. Your doctor may suggest undergoing genetic testing to correctly identify the responsible gene and possibly provide some insight into the hereditary nature of the condition. Since many of the inherited retinal diseases may also involve other areas of the body it is of great importance for your doctor to also inquire about and investigate these other potential conditions.

How are inherited/genetic retinal diseases treated?

First and foremost your doctor will make sure that you do not have an underlying disease that can be treated (examples are Refsum or Bassen-Kornzweig Syndrome). Although most patients with diseases such as vitelliform dystrophy and flecked retina may continue to have good vision throughout life, patients with diseases like Stargardt’s or Retinitis Pigmentosa may develop very poor vision. With the exception of wet macular degeneration, which has treatments that can be successful if it is caught early, the vast majority of these diseases unfortunately have no treatment at the present time. Low vision specialists may be consulted to maximize vision potential with glasses or magnifiers. Patients are also monitored regularly to make sure they do not develop any additional complications that may result from their retinal disease. For example, patients with Stargardt’s disease, Best’s disease, or pattern dystrophies are evaluated for choroidal neovascularization (the growth of abnormal blood vessels under the retina), and patients with retinitis pigmentosa are monitored for the development of cataracts and macular edema. These complications may be managed with injections, eye drops, or cataract surgery in the case of visually significant cataracts.

What does the future hold for the management of inherited and genetic retinal diseases?

It is understandably frustrating for a patient to be told that currently there is no treatment or cure for their eye disease. However the future holds great promise in the area of inherited and genetic retinal disease. There are several trials underway utilizing gene therapy as a potential treatment for hereditary forms of retinal disease. Gene therapy essentially works by replacing or compensating for the defective DNA that caused the disease in the first place. Gene therapy trials for Leber’s Congenital Amaurosis in particular have already shown some remarkable results.

Retina Consultants of Houston is specialized in diagnosing and evaluating inherited and genetic retinal diseases. RCH provides the latest diagnostic and imaging technologies and can arrange genetic testing services when suitable. RCH is on the forefront of research and is a leader in clinical trials. We strive to offer patients the most up-to-date, safest, and most effective therapies as they become available. Please contact us to inquire about participation in any future clinical trials on inherited and genetic retinal conditions.