Best disease was first described by Frederich Best in 1905. It is characterized by a striking accumulation of lipofuscin-like material in the macula that often results in an "egg-yolk-like" appearance. In addition, patients affected with Best's disease display an abnormal electrophysiologic sign known as a depressed Arden ratio. The electro-oculogram is a measurement of the electric potential that normally exists across the retinal pigment epithelium. This potential normally doubles in response to bright light. However, in Best's disease, this increase does not exist. This test can be used to diagnose patients without classic macular lesions, as well as identifying patients that are unlikely to have the disease.
Retinal appearance of a 12 year old boy with Best's disease. The egg-yolk-like yellow deposit is abnormal.
In 1992, we used classic linkage analysis in a large family affected with Best's disease to localize the gene to chromosome 11q13. To date, the specific gene that is mutated has not been identified. The retinal outer membrane gene (ROM-1) lies within this region, but extensive mutation and sequence analysis has indicated that it is not involved in the pathogenesis of Best's disease.
An electro-oculogram is performed on a child during a field trip. This test can detect Best's disease before it is clinically manifest.
