What is Best vitelliform macular dystrophy?
Best vitelliform macular dystrophy (Best disease) is a form of macular degeneration characterized by a loss of central vision. It is also known by the name vitelliform macular dystrophy.
What are the symptoms?
Best disease affects the macula, the central part of the retina responsible for fine visual detail and color perception. The retina and its component photoreceptor cells are essential to vision as they convert light into electrical impulses and then transfer these impulses to the brain via the optic nerve.
Although the age of onset for those with Best disease can vary, it is usually diagnosed during childhood or adolescence. In the initial stages, a bright yellow cyst (fluid-filled sac) forms under the retinal pigment epithelium (RPE) beneath the macula. Upon examination, the cyst looks like a sunny-side-up egg. Despite the presence of the cyst, visual acuity may remain normal or near normal (between 20/30 and 20/50) for many years. Peripheral (side) vision usually remains unaffected.
In many individuals with Best disease, the cyst eventually ruptures. Fluid and yellow deposits from the ruptured cyst spread throughout the macula. At this point the macula has a scrambled egg appearance. Once the cyst ruptures, the macula and the underlying RPE begin to atrophy (degenerate) causing further vision loss. As a result, central vision tends to deteriorate to about 20/100 later in life. However, Best disease does not always affect both eyes equally. Many individuals retain useful central vision in one eye with a visual acuity of about 20/40 in the lesser-affected eye.
In some cases, Best disease does not progress far enough to cause significant central vision loss. However, retinal specialists can still detect the disease using sophisticated diagnostic tests that measure the function of the RPE and the retina. Individuals with Best disease are also often farsighted. Farsightedness can be corrected with glasses. Source: Foundation Fighting Blindness
Is it an inherited disease?
Yes. Best disease is a rare autosomal dominant disorder.
Is there a genetic test available?
Yes. The John and Marcia Carver Nonprofit Genetic Testing Laboratory has available a clinical nonprofit test for Best Disease. See Genetic Tests We Offer
How can I order a genetic test for Best Disease?
The John and Marcia Carver Nonprofit Genetic Testing Laboratory has a clinical test available for Best Disease. For more information, you can start by following this link.
Is there a clinical trial available for this particular condition?
Research regarding the eye and blinding eye diseases is ongoing and the answer to this question might change on any given day. Thankfully there are resources available today to assist anyone interested in monitoring progress.
Where can I learn more about Best disease?
GeneTests is a publicly funded web site that provides medical genetics information. While primarily targeted to physicians, researchers and other healthcare providers, patients and their families interested in a reliable resource for their own research will find this up-to-date comprehensive web site an invaluable tool. See vitelliform macular dystrophy as found on GeneTests.org
The Genetic and Rare Diseases Information Center (GARD), a collaborative effort of two agencies of the National Institutes of Health: The Office of Rare Diseases Research (ORDR) and the National Human Genome Research Institute (NHGRI), is another most excellent resource.
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If you have any specific questions about Best Disease, please consult your personal physician.
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