Differentiation between optic disc drusen and optic disc oedema using fundus photography.

To describe a funduscopic sign that can be used to differentiate between optic disc drusen (ODD) and optic disc oedema (ODE). A total of 73 eyes from 73 consecutive subjects with disc margin blurring who had been evaluated using spectral-domain optical coherence tomography (SD-OCT) were included. Final diagnosis was made by SD-OCT; ODD was defined by direct visualization of ODD, while ODE was defined by documentation of retinal nerve fibre layer oedema (nasal retinal nerve fibre layer thickness >78.0 μm). Peripapillary retina was selected as a two-disc-diameter-sized square image from the fundus photograph. Using MATLAB software, colour photographs were converted to indexed image of eight colours. Presence of a smooth contour strip between the nasal disc margin and juxtapapillary retina was defined as a halo. Whether the halo could predict the ODD was analysed retrospectively. The halo sign was detected in 45 eyes (100%) with ODD including one eye with both ODD and ODE. No eyes with ODE alone showed the halo sign. The halo sign implied the presence of ODD (Cohen's kappa = 1.000, p < 0.001) and the absence of ODE (Cohen's kappa = 0.971, p < 0.001). The halo sign showed a good interobserver reliability [ICC (2, 1) = 0.944, 95% confidence interval 0.912-0.964]. SD-OCT images showed that halos represented retinal elevations above ODD. In the patients with blurred disc margin, the presence of a halo strongly suggested underlying ODD rather than ODE.

Lee KM ，Woo SJ ，Hwang JM 《-》

Morphologic Features of Buried Optic Disc Drusen on En Face Optical Coherence Tomography and Optical Coherence Tomography Angiography.

To evaluate and compare the morphologic characteristics of buried optic disc drusen (ODD) and optic disc edema (ODE) by using en face optical coherence tomography (OCT) and OCT angiography (OCTA). Retrospective, cross-sectional study. We reviewed the medical records of 61 patients (92 eyes) with buried ODD, 45 patients (62 eyes) with ODE, and 42 normal-appearing fellow eyes examined at 1 referral center between November 1, 2017 and April 30, 2019. Characteristic en face OCT and OCTA findings of buried ODD compared to those of ODE and normal optic discs were investigated. On en face OCT, all buried ODD were visualized as hyperreflective kidney-shaped masses well demarcated from the optic nerve axons, whereas ODE was visualized as ill-defined boundaries confluent with the retinal nerve fibers. On OCTA, 25.0% of the eyes with buried ODD showed a C-shaped vessel density decrease in the nasal radial peripapillary capillary layer, while 40.3% of the eyes with ODE had nonspecific focal vessel density decrease around the optic nerve head. Larger ODD were significantly associated with a vessel density decrease on OCTA (P = .009). The disc diameter positively correlated with the ODD area (r = 0.245; P = .018) and negatively correlated with the ODD height (r = -0.237; P = .023). En face OCT showed the characteristic features of buried ODD compared to those of ODE or normal optic discs. The demarcation of buried ODD from the optic nerve axons on en face OCT and the poor vascular perfusion of buried ODD on OCTA suggest that buried ODD are materials deposited around the optic disc rather than the herniated optic nerve axon fibers.

Kim MS ，Lee KM ，Hwang JM ，Yang HK ，Woo SJ ... -  《-》

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

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.

Lee KM ，Woo SJ ，Hwang JM 《-》

Sensitivity and specificity of time-domain and spectral-domain optical coherence tomography in differentiating optic nerve head drusen and optic disc oedema.

To evaluate the efficacy of time-domain optical coherence tomography (TD-OCT) and spectral-domain optical coherence tomography (SD-OCT) in differentiating between optic nerve head drusen (ONHD) and optic disc oedema (ODE). We studied 66 patients with ONHD, 31 patients with ODE, and 70 controls using TD-OCT and SD-OCT. We analysed two aspects of the tomographic findings: (i) quantitative, through measurement of the retinal nerve fibre layer (RNFL) and papillary elevation; and (ii) qualitative, through assessment of the hyporeflective space, morphology of the internal contour, focal papillary mass and RNFL increases in seven contiguous clock hours. We evaluated the sensitivity, specificity, intra-class correlation coefficient (ICC), and inter-observer agreement (κ). The quantitative analysis of the RNFL revealed an average thickness of the RNFL <124μm with TD-OCT (sensitivity=91%; specificity=94%) and <116μm with SD-OCT (sensitivity=91%; specificity=97%). The thickness of the nasal quadrant was <108μm with TD-OCT (sensitivity=89%; specificity=87%) and with SD-OCT was <92μm (sensitivity=88%; specificity=94%), however without significant differences between the nasal, superior and inferior quadrants' and average thickness. The measurement of papillary elevation was 0.85mm with TD-OCT (sensitivity=96%; specificity=84% [ICC=0.96]) and was <0.80 mm with SD-OCT (sensitivity=86%; specificity=87% [ICC=0.94]). The abrupt termination of the hyporeflective space measured with TD-OCT had sensitivity=79% and specificity=90% (κ=0.60) and with SD-OCT had sensitivity=88% and specificity=89% (κ=0.75); the irregularity of the internal contour with TD-OCT had sensitivity=80% and specificity=90% (κ=0.70) and with SD-OCT had sensitivity=88% and specificity=90% (κ=0.75); and the absence of seven contiguous clock hours had values of sensitivity=97% and specificity=77% with TD-OCT and had sensitivity=98% and specificity=77% with SD-OCT. Optical coherence tomography allowed for differentiation between ONHD and ODE, yielding similar results with TD-OCT and SD-OCT. The new quantitative parameters of papillary elevation and RNFL measurements showed greater sensitivity and specificity than the qualitative criteria.

Flores-Rodríguez P ，Gili P ，Martín-Ríos MD 《-》

Differentiating optic disc edema from optic nerve head drusen on optical coherence tomography.

Johnson LN ，Diehl ML ，Hamm CW ，Sommerville DN ，Petroski GF ... -  《-》