Discriminating Between Papilledema and Optic Disc Drusen Using 3D Structural Analysis of the Optic Nerve Head.

The distinction of papilledema from other optic nerve head (ONH) lesions mimicking papilledema, such as optic disc drusen (ODD), can be difficult in clinical practice. We aimed the following: (1) to develop a deep learning algorithm to automatically identify major structures of the ONH in 3-dimensional (3D) optical coherence tomography (OCT) scans and (2) to exploit such information to robustly differentiate among ODD, papilledema, and healthy ONHs. This was a cross-sectional comparative study of patients from 3 sites (Singapore, Denmark, and Australia) with confirmed ODD, those with papilledema due to raised intracranial pressure, and healthy controls. Raster scans of the ONH were acquired using OCT imaging and then processed to improve deep-tissue visibility. First, a deep learning algorithm was developed to identify major ONH tissues and ODD regions. The performance of our algorithm was assessed using the Dice coefficient. Second, a classification algorithm (random forest) was designed to perform 3-class classifications (1: ODD, 2: papilledema, and 3: healthy ONHs) strictly from their drusen and prelamina swelling scores (calculated from the segmentations). To assess performance, we reported the area under the receiver operating characteristic curve for each class. A total of 241 patients (256 imaged ONHs, including 105 ODD, 51 papilledema, and 100 healthy ONHs) were retrospectively included in this study. Using OCT images of the ONH, our segmentation algorithm was able to isolate neural and connective tissues and ODD regions/conglomerates whenever present. This was confirmed by an averaged Dice coefficient of 0.93 ± 0.03 on the test set, corresponding to good segmentation performance. Classification was achieved with high AUCs, that is, 0.99 ± 0.001 for the detection of ODD, 0.99 ± 0.005 for the detection of papilledema, and 0.98 ± 0.01 for the detection of healthy ONHs. Our artificial intelligence approach can discriminate ODD from papilledema, strictly using a single OCT scan of the ONH. Our classification performance was very good in the studied population, with the caveat that validation in a much larger population is warranted. Our approach may have the potential to establish OCT imaging as one of the mainstays of diagnostic imaging for ONH disorders in neuro-ophthalmology, in addition to fundus photography.

Girard MJA ，Panda S ，Tun TA ，Wibroe EA ，Najjar RP ，Aung T ，Thiéry AH ，Hamann S ，Fraser C ，Milea D ... -  《-》

The Role of Optical Coherence Tomography in Differentiating Optic Disc Drusen from Optic Disc Edema.

An elevated optic nerve head can be an ominous sign, sometimes signifying an underlying basis for raised intracranial pressure. Alternatively, patients may harbor a different mechanism for this optic nerve head appearance, including optic disc drusen (ODD), which does not confer any life-threatening implications. It is important to refine the approach to distinguishing ODD from papilledema because this is a relatively common, and important, conundrum encountered in clinical practice. Optical coherence tomography (OCT) is a noninvasive, readily accessible, and cost-effective ocular imaging technique that can improve the diagnostic accuracy for detecting ODD; or, instead, increase the index of suspicion for papilledema, thus prompting additional investigations needed to identify (or exclude) potential causes of raised intracranial pressure. In this review, we will discuss the value of OCT in the diagnostic approach to cases of mild optic disc elevation, with acknowledgment of the potential pearls and pitfalls of this imaging technology. In particular, we will emphasize the helpful role OCT can play in differentiating cases of ODD from mild papilledema in the context of idiopathic intracranial hypertension (IIH).

Costello F ，Malmqvist L ，Hamann S 《Asia-Pacific Journal of Ophthalmology》

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 ... -  《-》

Are Macula or Optic Nerve Head Structures Better at Diagnosing Glaucoma? An Answer Using Artificial Intelligence and Wide-Field Optical Coherence Tomography.

Chiang CYN ，Braeu FA ，Chuangsuwanich T ，Tan RKY ，Chua J ，Schmetterer L ，Thiery AH ，Buist ML ，Girard MJA ... -  《Translational Vision Science & Technology》

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 《-》