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Der Ophthalmologe : Zeitschrift Der... Oct 2016Glaucoma is defined as a progressive neuropathy of the optic nerve, characterized by specific changes of the optic disc, parapapillary region, and retinal nerve fiber... (Review)
Review
BACKGROUND
Glaucoma is defined as a progressive neuropathy of the optic nerve, characterized by specific changes of the optic disc, parapapillary region, and retinal nerve fiber layer.
OBJECTIVES
Characteristic glaucomatous changes of the optic disc, parapapillary region, and retinal nerve fiber layer are discussed and their ophthalmoscopic examination is described.
MATERIALS AND METHODS
A literature search in the PubMed database was conducted.
RESULTS
A systematic step-by-step approach to a qualitative and quantitative ophthalmoscopic evaluation of the optic disc regarding glaucomatous damage is presented.
CONCLUSION
A systematic, clinical, qualitative, and quantitative assessment of the optic disc can be performed with little effort and forms the basis for diagnosis and treatment of glaucoma.
Topics: Diagnosis, Differential; Glaucoma; Humans; Image Interpretation, Computer-Assisted; Ophthalmoscopy; Optic Disk; Reproducibility of Results; Sensitivity and Specificity
PubMed: 27448220
DOI: 10.1007/s00347-016-0331-8 -
Diabetic Medicine : a Journal of the... Mar 2021
Topics: Diabetes Mellitus, Type 2; Diabetic Retinopathy; Diagnosis, Differential; Fundus Oculi; Humans; Male; Middle Aged; Optic Disk; Papilledema
PubMed: 32985007
DOI: 10.1111/dme.14398 -
BioMed Research International 2015
Topics: Diagnostic Imaging; Humans; Magnetic Resonance Imaging; Optic Disk; Retina; Tomography, Optical Coherence
PubMed: 26221591
DOI: 10.1155/2015/371312 -
IEEE Journal of Biomedical and Health... Nov 2014Retinal image analysis is increasingly prominent as a nonintrusive diagnosis method in modern ophthalmology. In this paper, we present a novel method to segment blood...
Retinal image analysis is increasingly prominent as a nonintrusive diagnosis method in modern ophthalmology. In this paper, we present a novel method to segment blood vessels and optic disk in the fundus retinal images. The method could be used to support nonintrusive diagnosis in modern ophthalmology since the morphology of the blood vessel and the optic disk is an important indicator for diseases like diabetic retinopathy, glaucoma, and hypertension. Our method takes as first step the extraction of the retina vascular tree using the graph cut technique. The blood vessel information is then used to estimate the location of the optic disk. The optic disk segmentation is performed using two alternative methods. The Markov random field (MRF) image reconstruction method segments the optic disk by removing vessels from the optic disk region, and the compensation factor method segments the optic disk using the prior local intensity knowledge of the vessels. The proposed method is tested on three public datasets, DIARETDB1, DRIVE, and STARE. The results and comparison with alternative methods show that our method achieved exceptional performance in segmenting the blood vessel and optic disk.
Topics: Algorithms; Databases, Factual; Diagnostic Techniques, Ophthalmological; Humans; Image Processing, Computer-Assisted; Optic Disk; Retina; Retinal Vessels
PubMed: 25265617
DOI: 10.1109/JBHI.2014.2302749 -
Survey of Ophthalmology 2020Modern advances in measuring and studying cerebrospinal fluid dynamics have furthered our understanding of intracranial pressure and its pathophysiological effects on... (Review)
Review
Modern advances in measuring and studying cerebrospinal fluid dynamics have furthered our understanding of intracranial pressure and its pathophysiological effects on the eye. In particular, the cerebrospinal fluid pressure and composition within the optic nerve subarachnoid space are key factors in diseases of the optic disk. Intracranial pressure and intraocular pressure establish a pressure gradient across the lamina cribrosa. Alterations in this translaminar cribrosa pressure difference induce structural deformations in the lamina cribrosa manifested clinically by the appearance of optic disk edema or optic disk cupping. Much has been learned about papilledema (i.e., optic disk edema due to elevated intracranial pressure) from clinical observations and studies on patients with idiopathic intracranial hypertension. Furthermore, optic nerve subarachnoid space hydrodynamics and translaminar cribrosa pressure difference are postulated to contribute to the pathogenesis of optic disk edema observed in spaceflight-associated neuroocular syndrome. Recently, a substantial body of literature has accumulated suggesting low intracranial pressure may be a risk factor for the development of glaucomatous optic disk cupping within the context of the translaminar cribrosa pressure difference and posterior scleral biomechanics.
Topics: Cerebrospinal Fluid Pressure; Humans; Intraocular Pressure; Magnetic Resonance Imaging; Optic Disk; Optic Nerve; Optic Nerve Diseases
PubMed: 31449832
DOI: 10.1016/j.survophthal.2019.08.005 -
Survey of Ophthalmology 2021Optical coherence tomography angiography (OCTA) is a noninvasive, depth-resolved imaging tool for the appraisement of retinal vascular changes. Since its introduction,... (Review)
Review
Optical coherence tomography angiography (OCTA) is a noninvasive, depth-resolved imaging tool for the appraisement of retinal vascular changes. Since its introduction, the understanding of diabetic retinopathy, age-related macular degeneration, central serous retinopathy, and other diseases has been enriched on many fronts. Its dyeless imaging property maps retinal as well as deeper choroidal vasculature in quick succession with good reproducibility. Hence, it can play an important role in the diagnosis and management of optic nerve-related diseases as well. A detailed literature review for its role in nonarteritic anterior ischemic optic neuropathy, papilledema, optic disc drusen, papillitis, hereditary optic neuropathies, central nervous system diseases, and others highlights its role. The whole spectrum of neuro-ophthalmological diseases shows consistent peripapillary and macular capillary changes with structural and functional correlation. The superficial and deeper retinal and choroidal vasculatures are affected depending on the nature of the disease process. Hence, OCTA positions itself as a useful, noninvasive tool in the armamentarium of a neuro-ophthalmologist in future; however, there are several limitations of the OCTA with respect to its technical abilities in challenging neuro-ophthalmic cases. Therefore, future research should be directed to enhance the technical capabilities of OCTA and to determine the more precise role of it in the prognosis of neuro-ophthalmic diseases.
Topics: Angiography; Fluorescein Angiography; Humans; Ophthalmology; Optic Disk; Reproducibility of Results; Tomography, Optical Coherence
PubMed: 33157113
DOI: 10.1016/j.survophthal.2020.10.009 -
Sensors (Basel, Switzerland) May 2023With recent advancements in artificial intelligence, fundus diseases can be classified automatically for early diagnosis, and this is an interest of many researchers....
With recent advancements in artificial intelligence, fundus diseases can be classified automatically for early diagnosis, and this is an interest of many researchers. The study aims to detect the edges of the optic cup and the optic disc of fundus images taken from glaucoma patients, which has further applications in the analysis of the cup-to-disc ratio (CDR). We apply a modified U-Net model architecture on various fundus datasets and use segmentation metrics to evaluate the model. We apply edge detection and dilation to post-process the segmentation and better visualize the optic cup and optic disc. Our model results are based on ORIGA, RIM-ONE v3, REFUGE, and Drishti-GS datasets. Our results show that our methodology obtains promising segmentation efficiency for CDR analysis.
Topics: Humans; Animals; Optic Disk; Artificial Intelligence; Glaucoma; Fundus Oculi; Abomasum
PubMed: 37430580
DOI: 10.3390/s23104668 -
Developmental Biology Apr 2021The vertebrate eye anlage grows out of the brain and folds into bilayered optic cups. The eye is patterned along multiple axes, precisely controlled by genetic programs,...
The vertebrate eye anlage grows out of the brain and folds into bilayered optic cups. The eye is patterned along multiple axes, precisely controlled by genetic programs, to delineate neural retina, pigment epithelium, and optic stalk tissues. Pax genes encode developmental regulators of key morphogenetic events, with Pax2 being essential for interpreting inductive signals, including in the eye. PAX2 mutations cause ocular coloboma, when the ventral optic fissure fails to close. Previous studies established that Pax2 is necessary for fissure closure and to maintain the neural retina -- glial optic stalk boundary. Using a Pax2 knock-in allele we discovered that the mutant optic nerve head (ONH) lacks molecular boundaries with the retina and RPE, rendering the ONH larger than normal. This was preceded by ventronasal cup mispatterning, a burst of overproliferation and followed by optic cup apoptosis. Our findings support the hypothesis that ONH cells are tripotential, requiring Pax2 to remain committed to glial fates. This work extends current models of ocular development, contributes to broader understanding of tissue boundary formation and informs the underlying mechanisms of human coloboma.
Topics: Animals; Animals, Genetically Modified; Body Patterning; Cell Proliferation; Coloboma; Eye; Female; Gene Expression Regulation, Developmental; Gene Knock-In Techniques; Male; Mice; Mice, Inbred C57BL; Optic Disk; PAX2 Transcription Factor; Retina; Stem Cells
PubMed: 33428890
DOI: 10.1016/j.ydbio.2020.12.020 -
Current Opinion in Ophthalmology Mar 2017This article reviews the recent findings with regard to the pathophysiology and clinical significance of optic disc hemorrhage in glaucoma. (Review)
Review
PURPOSE OF REVIEW
This article reviews the recent findings with regard to the pathophysiology and clinical significance of optic disc hemorrhage in glaucoma.
RECENT FINDINGS
Even though the pathophysiology of disc hemorrhage has been investigated in depth, its underlying mechanism remains unclear. The key disc hemorrhage mechanisms currently under discussion are mechanical vascular disruption and associated vascular susceptibilities. Recent technical advances in spectral-domain optical coherence tomography have yielded more compelling evidence of mechanical vascular disruption behind the pathogenesis of disc hemorrhage in glaucoma. Studies show that disc hemorrhage is associated with structural and functional glaucoma progression. Furthermore, recent findings suggest that disc hemorrhage can have different significances according to its location, recurrence, and associated underlying mechanism.
SUMMARY
The underlying mechanism of disc hemorrhage is complex like that of glaucoma. The ongoing controversy respecting the role of disc hemorrhage as a risk factor for glaucoma progression notwithstanding, special attention entailing closer follow-up and/or treatment escalation is recommended for patients with disc hemorrhage. Further studies investigating the unrevealed pathogenesis of disc hemorrhage and its prognostic value in glaucoma are warranted.
Topics: Disease Progression; Glaucoma; Humans; Optic Disk; Prognosis; Retinal Hemorrhage; Risk Factors; Tomography, Optical Coherence
PubMed: 27820751
DOI: 10.1097/ICU.0000000000000345 -
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi =... Oct 2023Glaucoma is one of blind causing diseases. The cup-to-disc ratio is the main basis for glaucoma screening. Therefore, it is of great significance to precisely segment...
Glaucoma is one of blind causing diseases. The cup-to-disc ratio is the main basis for glaucoma screening. Therefore, it is of great significance to precisely segment the optic cup and disc. In this article, an optic cup and disc segmentation model based on the linear attention and dual attention is proposed. Firstly, the region of interest is located and cropped according to the characteristics of the optic disc. Secondly, linear attention residual network-34 (ResNet-34) is introduced as a feature extraction network. Finally, channel and spatial dual attention weights are generated by the linear attention output features, which are used to calibrate feature map in the decoder to obtain the optic cup and disc segmentation image. Experimental results show that the intersection over union of the optic disc and cup in Retinal Image Dataset for Optic Nerve Head Segmentation (DRISHTI-GS) dataset are 0.962 3 and 0.856 4, respectively, and the intersection over union of the optic disc and cup in retinal image database for optic nerve evaluation (RIM-ONE-V3) are 0.956 3 and 0.784 4, respectively. The proposed model is better than the comparison algorithm and has certain medical value in the early screening of glaucoma. In addition, this article uses knowledge distillation technology to generate two smaller models, which is beneficial to apply the models to embedded device.
Topics: Humans; Optic Disk; Glaucoma; Algorithms; Diagnostic Techniques, Ophthalmological; Databases, Factual
PubMed: 37879921
DOI: 10.7507/1001-5515.202208061