PURPOSE: Our aim was to analyze retinal structure in young patients with Best disease with reference to future gene therapy.

METHODS: This was a retrospective observational spectral domain optical coherence tomography study of four patients aged 10 years or less with Best disease.

RESULTS: Findings ranged from subtle thickening at the level of the retinal pigment epithelium-photoreceptor interdigitation line, to subretinal fluid and precipitate-like changes at the level of the photoreceptor outer segments, and further to choroidal neovascularization. The photoreceptor inner segment ellipsoid layer could be visualized seemingly undisturbed above the vitelliform lesions, except in the case of choroidal neovascularization.

CONCLUSIONS: Clinical variability is evident even among young patients aged 10 years or less with Best disease. The earliest structural alterations seem to occur at the level of the retinal pigment epithelium-photoreceptor interdigitation line. The photoreceptor inner segment seems to be unaffected unless choroidal neovascularization develops, which seems promising regarding future gene therapy.