Which imaging test is used to identify optic nerve head drusen by showing hyper-reflective deposits?

• A. B-scan
• B. Fundus autofluorescence (FAF)
• C. Visual field testing
• D. RNFL OCT

Answer: (A)

Optic nerve head drusen are calcified deposits within the optic nerve head, and the test that best visualizes these calcifications is a B-scan ultrasound. On B-scan, drusen appear as bright, hyperreflective foci inside the optic nerve head and often show posterior acoustic shadowing, which helps confirm their presence even when they aren’t clinically visible. This makes buried drusen detectable when ophthalmoscopy is inconclusive.

Fundus autofluorescence can highlight drusen due to autofluorescent material, and functional tests like visual field testing or structural imaging like RNFL OCT provide information about the nerve’s function or fiber layer, but they do not show the characteristic hyperreflective deposits that ultrasound reveals.