Bilateral Optic Nerve Drusen

Clinical History

The patient presented with a headache and impaired vision.

Imaging Findings

The patient presented with a headache and visual impairment. Orbital CT was performed due to suspected papilledema on ophthalmologic examination. CT along the axial plane showed rounded, small, calcified bodies confined to the disk surface bilaterally. There were no other abnormalities (Fig. 1a, b).

Discussion

Optic nerve drusen, known as hyaline bodies of the optic nerve, are acellular accretions of hyaline-like material. They occur on or near the surface of the optic disk and are commonly calcified. Clinically, drusen are usually asymptomatic and found incidentally on fundoscopic or orbital CT examination. Sometimes they may cause visual field defect. Migraine-like headaches are also known to occur. When they are located beneath the surface of the disk, they may blur the disk contour and lead to misdiagnosis of papilledema as was the case with our patient. On CT, drusen appear as small, rounded, calcified lesions centered on the disk surface and are often bilateral (up to 73%). For buried drusen, which are fundoscopically undetectable, CT may be the only method of diagnosis. Optic nerve drusen are difficult to visualize on MR images.

Differential Diagnosis List

Final Diagnosis

Bilateral optic nerve drusen.

URL:	https://www.eurorad.org/case/2732
DOI:	10.1594/EURORAD/CASE.2732
ISSN:	1563-4086