The RNFL and the prelaminar tissue are shown in red, the RPE in pink, all other retinal layers in cyan, the choroid in green, the peripapillary sclera in yellow, the LC in blue, noise in grey and the vitreous humor in black.These include the thinning of the retinal nerve fiber layer (RNFL) 1, 2, 3, changes in the minimum-rim-width 4, choroidal thickness 5, 6, lamina cribrosa (LC) depth 7, 8, 9, and posterior scleral thickness 10; and migration of the LC insertion sites 11, 12.
![]() The segmentation accuracy of these tools is also affected by the reduced deep-tissue visibility and shadow artifacts 26 in the OCT images. Combining compensation technology (to remove the deleterious effects of light attenuation) 27 with our recently proposed methods, we were able to isolate the ONH tissues more accurately. Express Digital Darkroom 8.9 Gen Manual Input AndYet, the histogram-based approach was limited as it required an initial manual input and could not fully separate different tissues (e.g. On the other hand, the patch-based approach failed to offer precise tissue boundaries, failed to separate the LC from the sclera, and presented artificial LC-scleral insertions. We present a comparison with our earlier deep-learning (patch-based) approach to assert the robustness of DRUNET. Our long-term goal is to offer a framework for the automated extraction of neural and connective tissue structural parameters from OCT images of the ONH. This study adhered to the tenets of the Declaration of Helsinki and was approved by the institutional review board of the hospital. ![]() The inclusion criteria for normal controls were: an intraocular pressure (IOP) less than 21 mmHg, healthy optic nerves with a vertical cup-disc ratio (VCDR) less than or equal to 0.5 and normal visual fields test. Primary open angle glaucoma was defined as glaucomatous optic neuropathy (GON; characterized as loss of neuroretinal rim with a VCDR 0.7 classmjx-math 0.7 andor focal notching with nerve fiber layer defect attributable to glaucoma andor asymmetry of VCDR between eyes 0.2 classmjx-math 0.2 ) with glaucomatous visual field defects. Primary angle closure glaucoma was defined as the presence of GON with compatible visual field loss, in association with a closed anterior chamber angle andor peripheral anterior synechiae in at least one eye. A closed anterior chamber angle was defined as the posterior trabecular meshwork not being visible in at least 180 of anterior chamber angle. The images were acquired by a single operator (TAT), masked to diagnosis with the right ONH being imaged in all the subjects, unless the inclusion criteria were met only in the left eye, in which case the left eye was imaged. A horizontal B-scan (0) of 8.9 mm (composed of 768 A-scans) was acquired through the center of the ONH for all the subjects using spectral-domain OCT (Spectralis, Heidelberg Engineering, Heidelberg, Germany). Each OCT image was averaged 48x and enhanced depth imaging (EDI) was used for all scans. AC can help mitigate blood vessel shadows and enhance the contrast of OCT images of the ONH 27, 28. A threshold exponent of 12 (to limit noise over-amplification at high depth) and a contrast exponent of 2 (for improving the overall image contrast) were used for all the B-scans 28. Noise (in gray) and the vitreous humor (in black) were also isolated. Note that we were unable to obtain a full thickness segmentation of the peripapillary sclera and the LC due to limited visibility 28.
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