optic disc drusen
Calcified deposits within the optic nerve head that can mimic papilledema and cause visual field defects.
Full Definition
Optic disc drusen are calcified, protein-lipid deposits that accumulate within the substance of the optic nerve head, causing elevation and distortion of the optic disc that can closely mimic papilledema. These deposits are more common in Caucasians and can be inherited in an autosomal dominant pattern with variable penetrance. Drusen may be buried (not visible on ophthalmoscopy) or visible as glistening, refractile bodies on the disc surface. Unlike papilledema from increased intracranial pressure, optic disc drusen do not cause disc hyperemia, cotton-wool spots, or hemorrhages. The condition can cause progressive visual field defects, typically arcuate scotomas or nasal field defects, and occasionally transient visual obscurations. Diagnosis is confirmed using B-scan ultrasonography, optical coherence tomography, or fundus autofluorescence imaging. Recognition is crucial to avoid unnecessary neuroimaging and lumbar puncture that would be indicated for true papilledema.
Usage
Usage note: Distinguish clearly from papilledema; specify if buried or visible drusen when documenting.
In Context
- "B-scan ultrasonography confirmed optic disc drusen, ruling out papilledema from increased intracranial pressure." — Diagnostic workup
- "The patient's visual field defects were attributed to progressive optic disc drusen rather than glaucoma." — Visual field interpretation