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

Abstract

Background: To assess the efficacy of quantitative analysis of the optic nerve head and peripapillary retinal nerve fiber layer (RNFL) with the spectral-domain optical coherence tomography (SD-OCT) in differentiating optic disc edema (ODE) from optic nerve head drusen (ONHD).

Methods: Prospective clinical study. Twenty-five eyes of 25 ODE patients (group 1), 25 eyes of 25 ONHD patients (group 2), and 25 eyes of 25 healthy subjects were included. The thickness of the peripapillary RNFL, the thickness of the subretinal hyporeflective space (SHYPS), the area of the SHYPS, the horizontal length of the optic nerve head, and the angle between the temporal RNFL and the optic nerve head (α-angle) were evaluated with SD-OCT.

Results: The mean RNFL thickness was significantly greater in group 1 when compared with group 2 and control group (P < 0.001). The receiver operating characteristic curve areas for temporal and nasal RNFL thicknesses in differentiating group 1 and group 2 were 0.819 and 0.851, respectively (for temporal RNFL thickness >101.5 μm: sensitivity 92%, specificity 65%; for nasal RNFL thickness >74.5 μm: sensitivity 92%, specificity 47%). The mean SHYPS thickness, SHYPS area, and degree of the α-angle were greater in group 1 when compared with group 2 (P < 0.05). For the SHYPS thickness >464 μm: 85% sensitivity and 60% specificity; for the SHYPS area >811 μm: 85% sensitivity and 89% specificity; and for the α-angle >141°: 77% sensitivity and 95% specificity were obtained.

Conclusion: The quantitative analysis of the optic nerve head and peripapillary RNFL with SD-OCT can provide useful data in differentiating ODE from ONHD.