Differentiation of optic nerve head drusen and optic disc edema with spectral-domain optical coherence tomography

Abstract

Purpose: To evaluate the efficacy of spectral-domain optical coherence tomography (SD-OCT) in differentiating optic disc edema (ODE) and optic nerve head drusen (ONHD) and to reveal the differential points.

Design: Comparative case series.

Participants: Forty-five patients with ONHD, 15 patients with ODE, and 32 normal controls.

Methods: Spectral-domain optical coherence tomography was performed with scans on the optic nerve head and measurements of retinal nerve fiber layer thickness.

Main outcome measures: Qualitative findings of optic nerve head scans and retinal nerve fiber layer thickness profiles on SD-OCT.

Results: Optic nerve head drusen was visualized as a focal, hyperreflective, subretinal mass with a discrete margin on SD-OCT. The retinal nerve fiber layer was deformed and showed pseudoedema and high reflectance. The outer nuclear layer smoothly covered the drusen, which led to a hyporeflective, boot-shaped area adjacent to the drusen. In ODE, peripapillary retinal nerve fiber layers were significantly thicker in all sections than ONHD (average thickness of ODE: 174.1±53.5 μm vs ONHD: 119.2±20.2 μm vs control: 103.4±19.1 μm, P<0.001). Retinal nerve fiber thickness in the nasal section provides a good differential marker for ODE from ONHD (area under receiver operating characteristic curve = 0.866).

Conclusions: With the use of SD-OCT, noninvasive and accurate differentiation of ONHD and ODE is possible.