Best's Disease

[Ms. Kathy]

Best's Disease

Best's is an inherited disease rather much like macular degeneration and Stargardt's in the loss of central vision. The definiton below comes from EyeMD.com

Best's Disease
Also referred to as:
Vitelliform Macular Dystrophy


Yellowish material has accumulated under the macula (near the center of the photo) giving it an "egg yolk" appearance


Best's disease is a dominantly inherited condition affecting the macula and often involves both eyes. The symptoms vary greatly in severity, ranging from mild blurring to extremely distorted central vision or a central blind spot. It causes yellowish material to collect within the delicate retinal cells, giving the macula an "egg yolk" appearance. The disease is usually diagnosed within the first two decades of life.

There are several stages of Best's disease, and its progression may span decades. Patients often notice early symptoms of decreased vision as teenagers if the lesion ruptures. This gives the macula a mottled appearance and is known as the "scrambled egg" stage. The prognosis for Best's is extremely variable, ranging from functional vision to central blindness. Many retain fairly good central vision until middle-age when there is a high risk of macular scarring, which destroys central vision, but leaves peripheral vision intact.

Since Best's is an inherited disease, patients are referred for genetic counseling. Tests can be done to identify and monitor the progression of the disease, but there is no treatment.

[Ms. Kathy]

Best's Disease - (Best's vitelliform macular dystrophy)
Source Link: www.medicalgeek.com/disease-syndromes-procedures/13975-bests-disease-bests-vitelliform-macular-dystrophy.html



What is Best's Disease?


Best's disease, also known as Best's vitelliform macular dystrophy, is an hereditary form of progressive macular dystrophy first identified in 1905.


The macula is a small area of about 1mm in diameter in the centre of the retina, at the back of the eye where there is a concentration of cone cells. These cells are responsible for colour vision, sharp visual acuity and central vision. There are 6-7 million cone cells in the retina, the highest concentration of which is in the fovea, a tiny area in the centre of the macula.


The condition can be identified between 3 and 15 years of age.


Causes of Best's disease


Best's vitelliform macular dystrophy is a condition that tends to run in families and its cause lies within individual genetic make-up.

Risk groups and factors
The condition tends to occur in families with a history of Best's.


Effects of Best's Disease
Sight loss can be variable but, like other macular problems, Best's disease threatens central vision in one or both eyes.


Electroretinogram tests, which assess the electrical response of the retina when stimulated by light, can be used to identify people with the problem.


Within 5 identifiable stages, examination of the eye discloses a distinct progression. At first and second stages, there may be little or no effect on sight.


Initially a recording of eye movements and eye position identifies abnormal electrical potential. Eyes will be tested resting or moving in dark and light conditions.


At the second stage (usually between 10-25 years of age), typical yellow spots, sometimes accompanied by material leaking into a space by the retina, can be observed; an observation called "egg-yolk" lesion.


When part of the lesion becomes absorbed this is identified as stage three. Even at this stage there may be little affect on vision.


At the fourth stage, when the "egg-yolk" breaks up, in a process referred to as "scrambled-egg", sight will probably be affected.

The fifth and final stage is when the condition causes the most severe sight loss.


Treatment


RNIB is not aware of any current effective treatment, but scientific research, both traditional and genetic, may provide useful treatments for the future.


Prognosis


In many people serious sight loss is avoided but others can lose sight which may approach levels which would qualify for registration as sight impaired (partially sighted).


Genetic implications


Best's is autosomal dominant. With such genetic conditions it is likely that there would be several affected individuals in successive generations but Best's can be erratic and may miss a generation.


Further information and counselling will be available from a specialist clinic and your GP will be able to advise you about local Genetic Services.