Best disease

Best Disease Best disease, also known as Best vitelliform macular dystrophy, is a genetic eye disorder that affects the macula, the central part of the retina responsible for sharp central vision. It is named after the German ophthalmologist Friedrich Best, who first described the condition in 1905.

Etiology

Best disease is caused by mutations in the BEST1 gene, which encodes the bestrophin-1 protein. This protein is involved in the regulation of ion transport across the retinal pigment epithelium (RPE), a layer of cells that supports the function of the retina.

Pathophysiology

The mutation in the BEST1 gene leads to the accumulation of lipofuscin, a yellowish pigment, in the RPE. This accumulation forms a characteristic lesion known as a vitelliform lesion, which resembles an egg yolk. Over time, this lesion can lead to degeneration of the macula and loss of central vision.

Clinical Presentation

Best disease typically presents in childhood or adolescence, although the age of onset can vary. The condition is often asymptomatic in the early stages, but as it progresses, patients may experience:

• Blurred or distorted central vision
• Difficulty reading or recognizing faces
• Loss of visual acuity

Diagnosis

Diagnosis of Best disease is based on clinical examination and specialized tests, including:

• Fundus examination: Reveals the characteristic vitelliform lesion in the macula.
• Electrooculography (EOG): Shows a reduced light peak-to-dark trough ratio, which is a hallmark of Best disease.
• Genetic testing: Confirms the presence of mutations in the BEST1 gene.

Management

There is currently no cure for Best disease, and management focuses on monitoring and supporting vision. Regular eye examinations are important to track the progression of the disease. Low vision aids and rehabilitation may help patients cope with vision loss.

Prognosis

The progression of Best disease is variable. Some individuals maintain good vision throughout their lives, while others may experience significant vision loss. The condition does not typically lead to complete blindness.

Research

Ongoing research is focused on understanding the molecular mechanisms of Best disease and developing potential therapies. Gene therapy and pharmacological approaches are being explored as possible treatments.

See Also

• Macular degeneration
• Retinal dystrophy
• Genetic eye disorders
• Best, F. (1905). "Ueber eine heredit re Maculaaffektion: Beitr ge zur Vererbungslehre." *Archiv f r Augenheilkunde*.
• Boon, C. J., et al. (2009). "The spectrum of ocular phenotypes caused by mutations in the BEST1 gene." *Progress in Retinal and Eye Research*.

NIH genetic and rare disease info

• NIH info on Best disease

Best disease is a rare disease.