To report a case of Best's disease with old-age-onset with unusual clinical features.

A 68-year-old woman with a six-month history of using oral steroids complained of decreased vision in both eyes. Fundus examination revealed a circular area of macular elevation measuring approximately 1.5 disc diameter size in both eyes. Optical coherence tomography (OCT) showed serous retinal detachment, but pigment epithelial detachment was seen only on fluorescein angiography and indocyanine green angiography. The patient received a diagnosis of chronic central chorioretinopathy with choroidal neovascularization. Photodynamic therapy (PDT) and intravitreal bevacizumab (IVB) injections were prescribed as treatment, but were ineffective. For a definitive diagnosis, we performed an electro-oculogram (EOG) and the result was abnormal with an Arden ratio below 1.5 in both eyes. A final diagnosis of Best's disease was established. Spectral domain OCT findings at the last visit showed a clearly visible RPE split and a low reflective space between the split RPE layers, as well as a high reflectivity corresponding to the subretinal material.

We report a case of Best's disease with old-age onset with unusual clinical features and abnormal EOG findings. Spectral domain OCT was helpful in evaluating the disease. Treatment with PDT and IVB was not effective.