Best disease (Best vitelliform macular dystrophy) is diagnosed using a combination of family history, characteristic macular appearance, and specialised retinal tests. It typically presents with a yellow “egg‑yolk” lesion at the macula in childhood or adolescence.
Ophthalmic Evaluation
Visual acuity testing and dilated fundus examination look for vitelliform lesions, atrophy, or scarring at the macula.
- OCT imaging shows subretinal deposits and helps stage the disease over time.
- Autofluorescence and fundus photography document the distribution and evolution of lesions.
- Both eyes are assessed because the condition is usually bilateral, though often asymmetric.
- Other macular disorders are excluded based on age, appearance, and test results.
Electrophysiology and Genetics
Additional tests confirm the diagnosis and allow accurate counselling.
- Electro‑oculography (EOG) typically shows a markedly reduced light‑rise despite relatively preserved electroretinography (ERG).
- Genetic testing can identify pathogenic variants in the BEST1 gene or related genes.
- Results help distinguish Best disease from other inherited macular dystrophies and inform prognosis.
- Family screening may detect asymptomatic carriers and guide monitoring strategies.
