Best Disease

Updated: Nov 30, 2023
  • Author: Paige J Richards, MD; Chief Editor: Donny W Suh, MD, MBA, FAAP, FACS  more...
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Best disease, also termed vitelliform macular dystrophy, is typically an autosomal dominant disorder that classically presents in childhood with the striking appearance of a yellow or orange yolklike lesion in the macula. [1] Dr Franz Best, a German ophthalmologist, described the first pedigree in 1905. [2]

The lesion evolves through several stages over many years, with increasing potential for adverse visual outcome. A hallmark of the disease is a markedly abnormal electro-oculogram (EOG) in all stages of progression and in phenotypically normal carriers. [1, 3] The adult form varies, as described and shown in the image below.

Adult vitelliform macular dystrophy resembles Best Adult vitelliform macular dystrophy resembles Best disease, but it can be differentiated by its later age of onset, smaller lesion, and normal electro-oculogram testing.


Lesions in Best disease are restricted to the eye. [1] No systemic associations exist. Abnormalities in the eye result from a disorder in the retinal pigment epithelium (RPE). Best disease is an inherited retinal dystrophy that results from a mutation in the BEST1 gene and is inherited in an autosomal dominant fashion. A dysfunction of the protein bestrophin results in abnormal fluid and ion transport by the RPE. [4] Lipofuscin (periodic acid-Schiff [PAS] positive) accumulates within the RPE cells and in the sub-RPE space, particularly in the foveal area. The RPE appears to have degenerative changes in some cases, and secondary loss of photoreceptor cells can occur over time. [5] Breakdown of RPE/Bruchs membrane can allow choroidal neovascularization to develop as a late complication.




United States

Best disease is rare.


Best disease is rare.


Visual acuity is good in the previtelliform stage. Even with the egg-yolk appearance, visual acuity is maintained in the range of 20/20 to 20/50 (6/6 to 6/15) for many years. The breakup of the vitelliform stage, leading to the scrambled egg stage, may be accompanied by visual acuity deterioration. It is the final stages of geographic RPE atrophy with possible development of choroidal neovascular membrane that is associated with further deterioration in visual acuity. [6, 7] These changes usually occur in individuals older than 40 years. Various studies have shown that most individuals retain reading and driving vision in at least 1 eye into adulthood (88% have 20/40 or better vision). Only 4% of these individuals develop vision less than 20/200 in the better eye.


Best disease is most common in individuals of European ancestry but can also be found in individuals of African and Hispanic ancestry.


No known gender predilection exists.


Usual onset of Best disease is from 3-15 years, with an average age of 6 years. The condition often is not detected until much later in the disease because visual acuity may remain good for many years. The atrophic stage usually occurs after age 40 years.



Prognosis for Best disease is mixed. Some carriers will never phenotypically express the disorder. Some individuals will never have progression beyond the earliest stages of the disease and will maintain better than 20/40 vision in both eyes. In general, most people will maintain reading vision in at least 1 eye throughout life. In one study, 88% of patients retained 20/40 or better visual acuity, and only 4% of them had 20/200 or worse visual acuity in the better eye. The deterioration of vision usually is very slow and is not significant in most individuals until after age 40 years. [8, 9, 10]


Patient Education

Genetic inheritance: Provide an explanation of autosomal dominant inheritance to the patient and family members. In genetic counseling, discuss carrier state, variable penetrance and expressivity, and implications for offspring. Recommend familial evaluation.

Occupational counseling: Discuss the patient's prognosis and the possible implications on career direction.

Routine examination: Emphasize regular examinations because changes in fundus appearance over time may elucidate the eventual prognosis. Conduct evaluation for choroidal neovascularization.

Amsler grid: Teach use of this tool to identify central visual field changes.

Low vision aids: Assistive devices may be necessary if visual acuity deteriorates. Refer to a low vision specialist or organization.

For excellent patient education resources, visit eMedicineHealth's Eye and Vision Center. Also, see eMedicineHealth's patient education article Macular Degeneration.