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

Abstract

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. Comparative case series. Forty-five patients with ONHD, 15 patients with ODE, and 32 normal controls. Spectral-domain optical coherence tomography was performed with scans on the optic nerve head and measurements of retinal nerve fiber layer thickness. Qualitative findings of optic nerve head scans and retinal nerve fiber layer thickness profiles on SD-OCT. 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). With the use of SD-OCT, noninvasive and accurate differentiation of ONHD and ODE is possible.