Best vitelliform macular dystrophy

What causes Best vitelliform macular dystrophy?

Best vitelliform macular dystrophy (BVMD) is caused by changes (mutations) in the BEST1 gene. This gene gives the body instructions for making a protein called bestrophin. Bestrophin acts as a channel that controls the movement of chloride ions within the retina. It is thought that mutations in the BEST1 gene affect the shape of the channel and its ability to properly regulate the flow of chloride. However, it is unclear how exactly this relates to the specific features of BVMD.

Last updated on 05-01-20

How is Best vitelliform macular dystrophy diagnosed?

Best vitelliform macular dystrophy (BVMD) may be diagnosed based on the findings on an exam of the fundus (the interior surface of the eye opposite the lens); an electrooculogram (EOG); and the family history. An eye exam may include other tests as well. A fundus exam may show a typical yellow yolk-like macular lesion.

The EOG, which reflects the retinal pigmentary epithelium function, is the most diagnostic test for evaluating vitelliform macular dystrophy. In the majority of the cases, a severe decrease occurs in light response, reflected by an Arden (light-peak/dark-trough) ratio of 1.1-1.5. (The normal Arden ratio is 1.8.) Carriers will also have an abnormal EOG result. No correlation exists between EOG result and disease stage, visual acuity, or patient age. EOG results are usually symmetric for both eyes.

The family history in affected people is often consistent with either autosomal dominant or autosomal recessive inheritance.

Genetic testing may also be used to make a diagnosis of BVMD. A BEST1 mutation is detected in about 96% of affected people who have an affected family member. In people with no family history of BVMD, the mutation detection rate ranges between 50-70%. A mutation in BEST1 gene is more probable when a vitelliform lesion is accompanied by a reduced Arden ratio on EOG testing. The exact type of genetic test ordered to confirm a diagnosis may depend on a person's ancestry, family history, and/or whether other eye disorders are also being considered.

Last updated on 05-01-20

How is Best vitelliform macular dystrophy inherited?

Best vitelliform macular dystrophy (BVMD) is most commonly inherited in an autosomal dominant manner, although a few cases with autosomal recessive inheritance have been reported.

In autosomal dominant inheritance, having one changed (mutated) copy of the responsible gene in each cell is enough to cause symptoms of the condition. When a person with an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit the mutated gene. Most people with BVMD have an affected parent, but some people have the condition as the result of a new mutation that occurred for the first time.

Autosomal recessive inheritance means that a person must have a mutation in both copies of the responsible gene in each cell to be affected. The parents of an affected person usually each carry one mutated copy of the gene and are referred to as carriers. Carriers typically do not show signs or symptoms of the condition. When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier.

Last updated on 05-01-20

What conditions are similar to Best vitelliform macular dystrophy?

Best vitelliform macular dystrophy (BVMD) is typically recognized by its distinct lesion in the macula, but there are a few diseases of the retina that may be confused with BVMD. They include:

  • Adult-onset vitelliform macular dystrophy (AVMD). This form of vitelliform macular dystrophy affects mainly middle-aged people and is inherited in an autosomal dominant manner. The findings on a fundus exam can easily be mistaken for BVMD, but the electrooculogram (EOG) is normal or only slightly reduced in affected people. There is significant overlap of signs and symptoms between BVMD and AVMD.

  • Age-related macular degeneration (AMD). This common disorder is characterized by drusen (yellow deposits under the retina); disruption of the pigmented layer of the retina (retinal pigment epithelium); and choroidal neovascularization (growth of new blood vessels in the choroid).

  • Bull's eye maculopathy. This descriptive clinical diagnosis can be seen in people with cone dystrophy, cone-rod dystrophy, Stargardt disease, and other conditions of the macula.

Other conditions that may be part of the differential diagnosis of BVMD include autosomal dominant vitreoretinochoroidopathy and retinitis pigmentosa.

Last updated on 05-01-20

Are there any clinical trials for Best vitelliform macular dystrophy?

The U.S. National Institutes of Health, through the National Library of Medicine, developed to provide patients, family members, and members of the public with current information on clinical research studies. To find these trials, click on the link above and use "Best vitelliform macular dystrophy" as your search term. After you click on a study, review its "eligibility" criteria to determine its appropriateness. Use the study’s contact information to learn more. Check this site often for regular updates.

You can also contact the Patient Recruitment and Public Liaison (PRPL) Office at the National Institutes of Health (NIH). We recommend calling the toll-free number listed below to speak with a specialist, who can help you determine if you are eligible for any clinical trials. If you are located outside the United States, and would like to be contacted via telephone, you will need to provide your telephone number in full, including area code and international dialing prefix.

Patient Recruitment and Public Liaison Office
NIH Clinical Center
Bethesda, Maryland 20892-2655
Toll-free: 800-411-1222
Fax: 301-480-9793
Web site:

Last updated on 05-01-20

What research is currently being done on Best vitelliform macular dystrophy?

You can find relevant articles on Best vitelliform macular dystrophy through PubMed, a searchable database of biomedical journal articles. Although not all of the articles are available for free online, most articles listed in PubMed have a summary available. To obtain the full article, contact a medical/university library or your local library for interlibrary loan. You can also order articles online through the publisher’s Web site. Using "Best vitelliform macular dystrophy" as your search term should help you locate articles. Use the advanced search feature to narrow your search results. Click here to view a search.

The National Library of Medicine (NLM) Web site has a page for locating libraries in your area that can provide direct access to these journals (print or online). The Web page also describes how you can get these articles through interlibrary loan and Loansome Doc (an NLM document-ordering service). You can access this page at the following link You can also contact the NLM toll-free at 888-346-3656 to locate libraries in your area.

Last updated on 05-01-20

What is Best vitelliform macular dystrophy?

Best vitelliform macular dystrophy (BVMD) is a slowly progressive form of macular degeneration. It usually begins in childhood or adolescence, but age of onset and severity of vision loss can vary. Affected people first have normal vision, followed by decreased central visual acuity and distorted vision (metamorphopsia). Peripheral vision is not affected. BVMD is characterized by atrophy of the retinal pigment epithelium (The retina is the back part of the eye that contains the specialized cells that respond to light, known as photoreceptors) and impaired central visual function. BVMD is usually inherited in an autosomal dominant manner, but autosomal recessive inheritance has been reported. The condition is typically caused by mutations in the BEST1 gene; in a few cases the cause is unknown. Treatment is symptomatic and involves the use of low vision aids, and direct laser treatment or photodynamic therapy. Newer treatment includes anti-VEGF agents (bevacizumab) and transcorneal electrical retinal stimulation.

Last updated on 05-01-20

Can individuals with Best vitelliform macular dystrophy become completely blind?

The severity of vision loss varies widely in individuals with Best vitelliform macular dystrophy. People with this condition often lose their central vision and their eyesight may become blurry or distorted. However, peripheral (side) vision and the ability to see at night usually remain unaffected.

Last updated on 05-01-20

What are the chances of developing Best vitelliform macular dystrophy in both eyes?

Various studies have shown that only about 4% of these individuals with Best vitelliform macular dystrophy develop vision less than 20/200 in the better eye.

Last updated on 05-01-20

How does Best vitelliform macular dystrophy affect vision?

Best vitelliform macular dystrophy affects the retina, the specialized light- sensitive tissue that lines the back of the eye. Specifically, it disrupts cells in a small area near the center of the retina called the macula. The macula is responsible for sharp central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces.

Best vitelliform macular dystrophy causes a fatty yellow pigment (lipofuscin) to build up in cells underlying the macula. Over time, the abnormal accumulation of this substance can damage cells that are critical for clear central vision. As a result, people with this disorder often lose their central vision, and their eyesight may become blurry or distorted. Best vitelliform macular dystrophy typically does not affect side (peripheral) vision or the ability to see at night.

Studies have shown that most people with Best vitelliform macular dystrophy retain enough vision for reading and driving in at least one eye into adulthood (88% have 20/40 or better vision). Vision usually deteriorates slowly and does not become significant until after age 40.

Last updated on 05-01-20

How might Best vitelliform macular dystrophy be treated?

There is no specific treatment for Best vitelliform macular dystrophy (BVMD) at this time. Low vision aids help affected people with significant loss of visual acuity. Laser photocoagulation, photodynamic therapy, and anti-VEGF (vascular endothelial growth factor) agents such as bevacizumab have shown limited success in treating some of the secondary features of BVMD such as choroidal neovascularization (when abnormal blood vessels grow under the macula and retina).

Last updated on 05-01-20

Name: Prevent Blindness America 211 West Wacker Drive, Suite 1700
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Name: National Alliance for Eye and Vision Research (NAEVR) 1801 Rockville Pike, Suite 400
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Name: Retina International Ausstellungsstr. 36 8005 Zurich
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Name: Foundation Fighting Blindness 7168 Columbia Gateway Drive, Suite 100
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Phone: +1-410-423-0600 TTY: 1-800-683-5551 Toll Free: 1-800-683-5555 Email: Url:
Name: American Foundation for the Blind 1401 South Clark Street Suite 730
Arlington, VA, 22202, United States
Phone: 212-502-7600 Toll Free: 800-232-5463 Fax : 888-545-8331 Email: Url:

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