Best vitelliform macular dystrophy (VMD) is an autosomal dominant macular dystrophy caused by heterozygous mutations in the bestrophin1 gene. Patients with this condition typically have an abnormal electrooculogram. We report a case of a 16-year-old male who presented with gradual progressive vision loss in the right eye. Ophthalmic assessment included funduscopy, optical coherence tomography (OCT), fluorescein angiography, electro-oculography, electroretinography, and genetic testing. Visual acuity was 20/500 and 20/20 in the right and left eyes, respectively. Ophthalmoscopy revealed round yellow lesions in both foveae similar to what is typically seen in Best disease. A subretinal hemorrhage surrounding the right foveal lesion was also noted. OCT demonstrated an elevated neurosensory retina with a subretinal lesion in the right macula. Fluorescein angiography of the right eye confirmed the presence of choroidal neovascularization. Genetic analysis of VMD2/BEST1 sequences confirmed the diagnosis of Best disease. However, contrary to what was expected, the patient's electro-oculography was normal. The findings of this case support a small number of previous reports demonstrating cases of Best disease with normal electro-oculography. While an abnormal electro-oculography along with the typical features of Best disease confirms the diagnosis, a normal result may not exclude the diagnosis. Genetic testing is probably the most important test for establishing the diagnosis of Best disease.
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