Differentiating mild papilledema and buried optic nerve head drusen using spectral domain optical coherence tomography

Purpose: To evaluate the clinical utility of spectral domain optical coherence tomography (SD-OCT) in differentiating mild papilledema from buried optic nerve head drusen (ONHD).

Design: Comparative case series.

Participants: Sixteen eyes of 9 patients with ultrasound-proven buried ONHD, 12 eyes of 6 patients with less than or equal to Frisén grade 2 papilledema owing to idiopathic intracranial hypertension. Two normal fellow eyes of patients with buried ONHD were included.

Methods: A raster scan of the optic nerve and analysis of the retinal nerve fiber layer (RNFL) thickness was performed on each eye using SD-OCT. Eight eyes underwent enhanced depth imaging SD-OCT. Images were assessed qualitatively and quantitatively to identify differentiating features between buried ONHD and papilledema. Five clinicians trained with a tutorial and masked to the underlying diagnosis independently reviewed the SD-OCT images of each eye to determine the diagnosis.

Main outcome measures: Differences in RNFL thickness in each quadrant between the 2 groups and diagnostic accuracy of 5 independent clinicians based on the SD-OCT images alone.

Results: We found no difference in RNFL thickness between buried ONHD and papilledema in any of the 4 quadrants. Diagnostic accuracy among the readers was low and ranged from 50% to 64%. The kappa coefficient of agreement among the readers was 0.35 (95% confidence interval, 0.19-0.54).

Conclusions: We found that SD-OCT is not clinically reliable in differentiating buried ONHD and mild papilledema.