Optometry and vision science : official publication of the American Academy of Optometry
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Buried disc drusen are an important differential diagnosis for papilledema. Spectral domain optical coherence tomography (SD-OCT) affords clinicians with new non-invasive opportunities to probe below the surface of the optic nerve. Clinicians may use the knowledge of this appearance to rule out buried disc drusen in patients with irregular optic nerve borders or a bulging, hyperemic appearance. ⋯ The hyporeflective appearance may not be anticipated by clinicians, as B-scans show calcified drusen as hyperreflective on echo. It is hypothesized that the hyporeflectant appearance of drusen is due to a constancy in refractive index through the druse, as OCT detects changes in optical reflectivity. Thus, drusen are likely dense and homogenous. SD-OCT may be more useful in those patients with buried disc drusen which are not calcified as B-scan often contributes little in such cases.