Diagnosis of optic nerve head drusen using enhanced depth imaging optical coherence tomography

To evaluate the efficacy of Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT) in differentiating between optic nerve head drusen (ONHD) and optic disc oedema (ODE).

This was a cross-sectional study of 140 patients: 83 patients with ONHD (49 hidden and 34 visible), 20 patients with pseudopapilloedema (without drusen), and 37 patients with ODE. EDI-OCT of the optic nerve was performed, selecting one high-resolution line from the HD 5-line raster protocol. Two observers blindly evaluated the presence of a hyporeflective core surrounded by a hyperreflective margin or border. The sensitivity, specificity, predictive values and posttest probability were evaluated as well as the inter-observer agreement (k).

EDI-OCT demonstrated a sensitivity of 92% (95% CI: 83%-96%), a specificity of 96% (95% CI: 87%-99%), with a positive predictive value of 97% and a negative predictive value of 89%. The inter-observer agreement was as remarkable as k = 0.8985 (95% CI 0.8252-0.9718). A positive EDI OCT increases the posttest probability to 97% (95% CI: 91%-99%); when negative, the posttest probability is reduced to 12% (95% CI: 6%-21%).

EDI-OCT allowed for differentiation between ONHD and ODE with high sensitivity and specificity.