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Optic disc detection

Fantin Girard, Conrad Kavalec, Farida Cheriet
Optic disc (OD) appearance in fundus images is one of the clinical indicators considered in the assessment of retinal diseases such as glaucoma. The cup-to-disc ratio (CDR) is the most common clinical measurement used to characterize glaucoma. However, the CDR only evaluates the relative sizes of the cup and the OD via their diameters. We propose to construct an atlas-based shape descriptor (ASD) to statistically characterize the geometric deformations of the OD shape and of the blood vessels' configuration inside the OD region...
January 2018: Journal of Medical Imaging
Kai Yu, Fei Shi, Enting Gao, Weifang Zhu, Haoyu Chen, Xinjian Chen
Optic nerve head (ONH) is a crucial region for glaucoma detection and tracking based on spectral domain optical coherence tomography (SD-OCT) images. In this region, the existence of a "hole" structure makes retinal layer segmentation and analysis very challenging. To improve retinal layer segmentation, we propose a 3D method for ONH centered SD-OCT image segmentation, which is based on a modified graph search algorithm with a shared-hole and locally adaptive constraints. With the proposed method, both the optic disc boundary and nine retinal surfaces can be accurately segmented in SD-OCT images...
March 1, 2018: Biomedical Optics Express
Katarzyna Walczak, Heike Meißner, Ursula Range, Andreas Sakkas, Klaus Boening, Mieszko Wieckiewicz, Ioannis Konstantinidis
PURPOSE: The aging of zirconia ceramics (Y-TZP) is associated with tetragonal to monoclinic phase transformation. This change in microstructure may affect the optical properties of the ceramic. This study examines the effect of aging on the translucency of different zirconia materials. MATERIALS AND METHODS: 120 disc-shaped specimens were fabricated from four zirconia materials: Cercon ht white, BruxZir Solid Zirconia, Zenostar T0, Lava Plus (n = 30 per group). Accelerated aging was performed in a steam autoclave (134°C, 0...
March 11, 2018: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
Natsuki Monai, Kodai Yamauchi, Reiko Tanabu, Takayuki Gonome, Sei-Ichi Ishiguro, Mitsuru Nakazawa
PURPOSE: To characterize the optical coherence tomography (OCT) appearances of photoreceptor degeneration in the rhodopsin P23H transgenic rat (line 2) in relation to the histological, ultrastructural, and electroretinography (ERG) findings. MATERIALS AND METHODS: Homozygous rhodopsin P23H transgenic albino rats (line 2, very-slow degeneration model) were employed. Using OCT (Micron IV®; Phoenix Research Labs, Pleasanton, CA, USA), the natural course of photoreceptor degeneration was recorded from postnatal day (P) 15 to P 287...
2018: PloS One
Gözde Hondur, Emre Göktaş, Lama Al-Aswad, Gülgün Tezel
Purpose: This pilot cross-sectional study aimed to determine age-related changes of the retinal nerve fiber layer (RNFL) thickness in retinal periphery by swept-source optical coherence tomography-based analysis. Methods: Forty eyes of 40 healthy subjects were studied in three age groups, group 1 (20-40 years, n=15), group 2 (41-60 years, n=14), and group 3 (≥61 years, n=11). Wide-angle swept-source optical coherence tomography scans, including the optic disc and macula, were montaged with the nasal peripheral optical coherence tomography images acquired with a contralateral gaze...
2018: Clinical Ophthalmology
Zhixi Li, Yifan He, Stuart Keel, Wei Meng, Robert T Chang, Mingguang He
PURPOSE: To assess the performance of a deep learning algorithm for detecting referable glaucomatous optic neuropathy (GON) based on color fundus photographs. DESIGN: A deep learning system for the classification of GON was developed for automated classification of GON on color fundus photographs. PARTICIPANTS: We retrospectively included 48 116 fundus photographs for the development and validation of a deep learning algorithm. METHODS: This study recruited 21 trained ophthalmologists to classify the photographs...
March 2, 2018: Ophthalmology
Tomofumi Tani, Atsushi Takahashi, Taiji Nagaoka, Akitoshi Yoshida
Purpose: To evaluate the retinal microcirculation using a segmental-scanning Doppler optical coherence tomography (DOCT) flowmeter in a patient with Takayasu's arteritis (TA) with aortic valve regurgitation (AR). Observations: We measured the retinal blood velocity (V), retinal blood flow (RBF), and retinal blood velocity profiles (RBVP) of the major retinal arterioles using a DOCT flowmeter. The arteries were measured at the straight portion 1 disc diameter from the optic disc...
April 2017: American Journal of Ophthalmology Case Reports
Zhichao Wu, Abinaya Thenappan, Denis S D Weng, Robert Ritch, Donald C Hood
Purpose: To compare two region-of-interest (ROI) approaches and a global thickness approach for capturing progressive circumpapillary retinal nerve fiber layer (cpRNFL) changes on optical coherence tomography (OCT) imaging. Methods: Progressive cpRNFL thickness changes were evaluated in 164 eyes with a clinical diagnosis of glaucoma or suspected glaucoma; all eyes underwent optic disc OCT imaging on two visits at least 1 year apart. Such changes were evaluated with a manual ROI approach (ROIM ), which involved manual identification of region(s) of observed or suspected glaucomatous damage...
February 2018: Translational Vision Science & Technology
Shuhui Wang, Yuqin Zuo, Ning Wang, Bin Tong
Objective: To investigate the manifestation characteristics of fundus fluorescence angiography (FFA) and its values in diagnosing diabetic retinopathy through comparing direct ophthalmoscopy. Methods: Two hundred fifty patients (500 eyes) who were suspected as diabetic retinopathy and admitted to the hospital between February 2015 and December 2016 were selected. They underwent direct ophthalmoscopy and FFA. The manifestation characteristics of FFA in the diagnosis of diabetic retinopathy were summarized...
November 2017: Pakistan Journal of Medical Sciences Quarterly
Hae-Young Lopilly Park, Jin Woo Kim, Chan Kee Park
OBJECTIVE: We used OCT angiography (OCT-A) to investigate parapapillary choroidal microvasculature dropout (MvD) in glaucomatous eyes with or without disc hemorrhage (DH), and the association with changes in retinal nerve fiber layer (RNFL) thickness. DESIGN: An observational case-control study. PARTICIPANTS: Eighty-two open-angle glaucoma (OAG) eyes with DH and 68 OAG eyes without DH that underwent at least 4 serial OCT examinations were included...
February 24, 2018: Ophthalmology
Yi-Quan Xiong, Yun Mo, Yu-Qi Wen, Ming-Ji Cheng, Shu-Ting Huo, Xue-Jiao Chen, Qing Chen
Optical coherence tomography (OCT) is an emergent imaging tool used for noninvasive diagnosis of skin diseases. The present meta-analysis was carried out to assess the accuracy of OCT for the diagnosis of skin cancer. We conducted a systematic literature search though EMBASE, Medline, PubMed, the Cochrane Library, and Web of Science database for relevant articles published up to June 6, 2017. The quality of the included studies was assessed using the QUADAS-2 tool and the Oxford Levels of Evidence Scale. Statistical analyses were conducted using the software Meta-Disc version 1...
February 2018: Journal of Biomedical Optics
Ou Tan, Liang Liu, Li Liu, David Huang
Purpose: To devise a method to quantify nerve fibers over their arcuate courses over an extended peripapillary area using optical coherence tomography (OCT). Methods: Participants were imaged with 8 × 8-mm volumetric OCT scans centered at the optic disc. A new quantity, nerve fiber flux (NFF), represents the cross-sectional area transected perpendicular to the nerve fibers. The peripapillary area was divided into 64 tracks with equal flux. An iterative algorithm traced the trajectory of the tracks assuming that the relative distribution of the NFF was conserved with compensation for fiber connections to ganglion cells on the macular side...
February 2018: Translational Vision Science & Technology
Ferdinando Bottoni, Matteo Cereda, Roberta Secondi, Sara Bochicchio, Giovanni Staurenghi
PURPOSE: To evaluate the clinical outcomes of vitrectomy with induction of posterior vitreous detachment for the treatment of optic disc pit maculopathy. METHODS: We retrospectively evaluated medical records and imaging studies of 11 consecutive patients with optic disc pit maculopathy who underwent vitrectomy at Sacco University Hospital, Milan, Italy, between October 2008 and December 2015. Induction of a posterior vitreous detachment (PVD) was the aim of our surgery...
February 6, 2018: Graefe's Archive for Clinical and Experimental Ophthalmology
Joo Yeon Kim, Ji Hwan Lee, Christopher Seungkyu Lee, Sung Chul Lee
BACKGROUND: Chorioretinitis is an unusual form of varicella zoster virus (VZV)-associated uveitis, and no report has described VZV-associated chorioretinitis using serial optical coherence tomography (OCT) images obtained during the course of resolution. CASE PRESENTATION: A 61-year-old woman presented with acute, unilateral vision loss in her right eye. Her visual acuity was count fingers in the right eye and 16/20 in the left eye, and she exhibited skin vesicles on her right forehead...
February 5, 2018: BMC Ophthalmology
Yoshiyuki Kita, Gábor Hollό, Akiko Murai, Ritsuko Kita, Akito Hirakata
PURPOSE: To determine the optical coherence tomography angiography (OCTA) characteristics of a case of optic disc melanocytoma (ODM) associated with glaucomatous visual field and retinal nerve fiber layer (RNFL) defects in normal tension glaucoma. METHODS: The left eye of a 37-year-old female patient followed for a stable ODM for 10 years was investigated with OCT, OCTA, fluorescein (FA), and indocyanine green (ICGA) angiography. The ODM was unchanged, but a previously unknown inferotemporal neuroretinal rim loss and inferotemporal and superotemporal wedge shape glaucomatous RNFL thinning were seen with corresponding glaucomatous visual field defects...
February 1, 2018: International Ophthalmology
Atsufumi Hirohata, Yuji Baba, Benedict A Murphy, Benny Ng, Yunqi Yao, Kazuki Nagao, Jun-Young Kim
The generation of spin-polarised carriers in a non-magnetic material holds the key to realise highly efficient spintronic devices. Recently, it has been shown that the large spin-orbit coupling can generate spin-polarised currents in noble metals such as tungsten and platinum. Especially, if small samples of such metals are rotated on a plane disc in the presence of a perpendicular magnetic field, the orbital angular momentum is altered leading to a segregation of spin up and spin down electrons, i.e., a spin current in the samples...
January 31, 2018: Scientific Reports
P Enders, F Schaub, W Adler, M M Hermann, T S Dietlein, C Cursiefen, L M Heindl
PurposeTo compare Bruch's membrane opening (BMO)-based spectral domain optical coherence tomography (SD-OCT) and margin based confocal scanning laser tomography (CSLT) of the optic nerve head (ONH) to visual field function in large optic discs (macrodiscs) and to assess performance for glaucoma detection.MethodsIn a case-control, cross-sectional study, 125 eyes of 125 patients with disc size >2.45 mm2 , thereof 44 glaucoma and 11 ocular hypertension (OHT) patients and 70 healthy controls underwent SD-OCT and CSLT examination, visual field testing and clinical evaluation...
February 2018: Eye
Jayoon Moon, Ki Ho Park, Dong Myung Kim, Seok Hwan Kim
PURPOSE: To determine the factors that influence the satisfaction of the 'ISNT rule' (neural rim width: inferior ≥ superior ≥ nasal ≥ temporal) in normal and glaucomatous eyes. METHODS: The medical records of patients that visited Boramae Medical Center, Seoul, Korea, were reviewed. Each group of normal and glaucomatous eyes was divided into subgroups based on whether or not they satisfied the ISNT rule. ISNT rule assessment was performed by measuring the rim width with stereoscopic optic disc photographs using ImageJ software...
January 25, 2018: Korean Journal of Ophthalmology: KJO
Ajoy Mandal, Maireyee Bhattacharya, Denis V Kuznetsov, Tapas Ghosh, Sudeshna Das Chakraborty, Biswarup Satpati, Vsevolod Mazov, Dulal Senapati
Decoupling of different plasmon resonance modes (in-plane, and out-of-plane dipole and quadrupole resonances) by tuning nanoparticle's size and shape offers a new field of plasmonics as colorimetric assay-based optical-ruler for ultra-trace sensing. Driven by its low cost, easy to perform and efficient way to measure trace level (up to 30 ppt in presence of common mining elements in natural gold ore) abundance, this study develops a highly selective and ultrasensitive turn-on colorimetric sensor to detect gold-ion from environmental samples...
January 17, 2018: Scientific Reports
Aastha Takkar, Darakshan Naheed, Mohit Dogra, Manoj K Goyal, Ramandeep Singh, Nalini Gupta, Kirti Gupta, B R Mittal, Vivek Lal
Optic disc edema may be caused by a number of conditions. A commonly ignored but important aspect is the presence of "infiltration" of disc; that may closely mimic disc edema. Disc edema, optic nerve dysfunction and a normal appearing disc in any combination may occur in infiltrative optic neuropathies. Identifying disc infiltration can aid in diagnosis of many sinister pathologies even in the absence of other specific clinical features. We describe two patients presenting with optic nerve dysfunction and infiltrated disc appearance, which on investigations were found to have underlying malignancies thereby underscoring the importance of detecting infiltrative optic neurpathies...
October 2017: Neuro-ophthalmology
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