Best's Disease

Best's disease, also known as Best's vilelliform macular dystrophy, is a hereditary form of progressive macular dystrophy.

The macula is located at the back of the eye. It is a small area of about 1mm in diameter from which we get our sharpest vision. In the macula there is a concentration of cone cells. These cells are responsible for color 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 center of the macula.

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

There are five stages to this disease as follows:

• Stage 1: 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.
• Stage 2: Usually occurs 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.
• Stage 3: When part of the lesion becomes absorbed, this is identified as stage three. Even at this stage there may be little effect on vision.
• Stage 4: At this stage, when the "egg-yolk" breaks up in a process referred to as "scrambled-egg", sight will probably be affected.
• Stage 5: The fifth and final stage is when the condition causes the most severe sight loss.

Gradual loss of central vision.

Best's vitelliform macular dystrophy is a condition that tends to run genetically in families.

There is no current conventional treatment.