We present a case of choroidal osteoma and report a pattern of optical coherence tomography and multifocal electroretinography with a literature review.

Using B-scan and CT, we performed OCT and MF-ERG in a patient diagnosed with choroidal osteoma. OCT revealed serous retinal detachment in the macula and a thick, irregular plate-like structure with high reflectivity in the choroidal mass lesion. MF-ERG demonstrated that Trace arrays show suppression of central and peripheral signals, especially in central lesions. Ring averages show reduced amplitudes in all locations, and 3D-topography of the response density shows marked suppression of the central signal and no foveal peak in comparison with the unaffected left eye.

In patients with choroidal osteoma, OCT can reveal thick plate-like high reflectivity with an irregular outer surface, and MF-ERG can predict retinal dysfunction.