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Microvascular changes in macula and optic nerve head after femtosecond laser-assisted LASIK: an optical coherence tomography angiography study
摘要： To measure the microcirculation change of macula and optic nerve head before and after femtosecond laser assisted laser in situ keratomileusis. In total 45 eyes from 45 subjects, who underwent FS-LASIK during June 2017 to December 2017 in Guangdong Provincial People’s Hospital, were recruited in this study. Vessel density in macula and optic nerve head were measured by optical coherence tomography angiography before and after transient elevation in intraocular pressure caused by application of suction ring during surgery. Vessel density (VD) at superficial (SCP) plexus of macular region did not differ after surgery (F(3,132) = 1.41, P = 0.24), while the deep (DCP) plexus of macular region significantly decreased 1 day after surgery (P = 0.001) but returned to its baseline value 1 month postoperatively (P = 0.1). Vessel density of optic nerve head region had no significant changes after surgery (F(2.51,95.18) = 0.6, P = 0.59). A short-term temporary decrease of vessel density at deep layer of macular region was observed in eyes undergoing FS-LASIK. However, the retinal capillary density went back to preoperative level 1 month after surgery. Therefore, transient IOP spike during FS-LASIK did not cause long-term decline of retinal microcirculation.
关键词： Optical coherence tomography angiography,Femtosecond laser-assisted LASIK,Microvascular changes,Macula,Optic nerve head
更新于2025-09-23 15:19:57
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Nick-named laser radars
摘要： In this article the laser-based technologies for remote sensing that use laser radar principles, but still known under other names like photonics radar, optical coherence tomography, aberrometry, etc., are reviewed A look into some examples of a variety of such nick-named instruments and technologies is proposed assessing the arguments of them, being the members of the laser radar family.
关键词： optical coherence tomography,photonics radar,microradar,aberrometry,laser radar
更新于2025-09-23 15:19:57
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Optic Nerve Head Volumetry by Optical Coherence Tomography in Papilledema Related to Idiopathic Intracranial Hypertension
摘要： Purpose: Idiopathic intracranial hypertension (IIH) leads to optic nerve head swelling and optic atrophy if left untreated. We wanted to assess an easy to perform volumetric algorithm to detect and quantify papilledema in comparison to retinal nerve fiber layer (RNFL) analysis using optical coherence tomography (OCT). Methods: Participants with and without IIH underwent visual acuity testing at different contrast levels and static perimetry. Spectralis-OCT measurements comprised standard imaging of the peripapillary RNFL and macular ganglion cell layer (GCL). The optic nerve head volume (ONHV) was determined using the standard segmentation software and the 3.45 mm early treatment diabetic retinopathy study (ETDRS) grid, necessitating manual correction within Bruch membrane opening. Three neuro-ophthalmologists graded fundus images according to the Frisén scale. A mixed linear model (MLM) was used to determine differences between study groups. Sensitivity and specificity was evaluated using the area under the receiver-operating characteristic (ROC). Results: Twenty-one patients with IIH had an increased ONHV of 6.46 ± 2.36 mm3 as compared to 25 controls with 3.20 ± 0.25 mm3 (P < 0.001). The ONHV cutoff distinguishing IIH from controls was 3.97 mm3 (i.e. no patient with IIH had an ONHV below and no healthy individual above this value). The area under the curve (AUC) for ONHV was 0.99 and for the RNFL at 3.5 mm 0.90. The Frisén scale grading correlated higher with the ONHV (r = 0.90) than with the RNFL thickness (r = 0.68). ONHV measurements were highly reproducible in both groups (coefficient of variation <0.01%). Conclusions: OCT-based volumetry of the optic nerve head discriminates very accurately between individuals with and without IIH. It may serve as a useful adjunct to the rating with the subjective and ordinal Frisén scale. Translational Relevance: A simple OCT protocol run on the proprietary software of a commercial OCT device can reliably discriminate between normal optic nerve heads or pseudo-papilledema and true papilledema while being highly reproducible. Our normative data and OCT preset may be used in further clinical studies.
关键词： optical coherence tomography,pseudotumor cerebri syndrome,idiopathic intracranial hypertension,papilledema,optic nerve head volume
更新于2025-09-23 15:19:57
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Future clinical applicability of optical coherence tomography angiography
摘要： Optical coherence tomography angiography (OCT-A) is an emerging technology that allows for the non-invasive imaging of the ocular microvasculature. Despite the wealth of observations and numerous research studies illustrating the potential clinical uses of OCT-A, this technique is currently rarely used in routine clinical settings. In this review, technical and clinical aspects of OCT-A imaging are discussed, and the future clinical potential of OCT-A is considered. An understanding of the basic principles and limitations of OCT-A technology will better inform clinicians of its future potential in the diagnosis and management of ocular diseases.
关键词： ocular microvasculature,corneal vascularisation image artifact,segmentation,optical coherence tomography angiography,optic nerve head disease,algorithm,retinal disease
更新于2025-09-23 15:19:57
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Evaluation of patients with diffuse unilateral subacute neuroretinitis by spectral domain optical coherence tomography with enhanced depth imaging
摘要： Background: The purpose of this study was to determine the value of spectral domain optical coherence tomography (SD-OCT) in assessing patients with diffuse unilateral subacute neuroretinitis (DUSN). Methods: This was an observational case series with clinical imaging correlation performed at the Retina and Vitreous Institute of Londrina and State University of Londrina, Paraná, Brazil. The series comprised ten consecutive patients with a confirmed diagnosis of DUSN, ie, seven patients with late-stage disease and three with early-stage disease, who were assessed by SD-OCT for mean macular, retinal nerve fiber layer, and choroidal thickness using enhanced depth imaging software. Results: Comparing the affected eye with the healthy fellow eye, significant diffuse atrophy of the retinal layers with a decrease in mean macular (P=0.004) and retinal nerve fiber layer (P=0.002) thickness was found in all cases. There was no difference in choroidal thickness (P=0.262). Conclusion: The correlation of SD-OCT results with central vision and funduscopic findings may explain the profound loss of visual function in patients with DUSN.
关键词： enhanced depth imaging,diffuse unilateral subacute neuroretinitis,optical coherence tomography,eye infections,parasitic,retinitis
更新于2025-09-19 17:15:36
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Retinal nerve fibre layer thickness in a healthy Nepalese population by spectral domain optical coherence tomography
摘要： Objective: To determine the normal values for peripapillary retinal nerve fibre layer thickness (RNFL) measured by spectral domain optical coherence tomography (SD-OCT) in a healthy Nepalese population and to compare the RNFL thicknesses between the genders and among the various age groups. Material and methods: One hundred and fifty six eyes of 156 healthy Nepalese subjects (66 males and 88 females) of various age groups were enrolled in this observational, cross-sectional, hospital-based study. The peripapillary RNFL of the randomly chosen eye of each subject was imaged with a high resolution SD-OCT (Spectralis HRA+OCT, Heidelberg Engineering). The RNFL thickness was measured around the optic nerve head using 16 automatically averaged, consecutive, circular B scans with a 3.4 mm diameter and compared between the genders and among the various age groups. Results: The mean age of the subjects was 38.94 ± 17.00 years (range - 14 to 76 years). The average peripapillary RNFL was found to be 102.64 ± 9.56 μm (95 % CI 97.01 - 101.93). The mean ± SD peripapillary RNFL measurements at the superior, nasal, inferior and temporal sectors in the study population were 129.51 ± 15.09 μm, 76.55 ± 12.02 μm, 134.53 ± 17.19 μm and 70.74 ± 15.53 μm respectively. The average RNFL thickness was 99.47 ± 10.18 μm in the male whereas it was 105.09 ± 8.31 μm in the female participants. The RNFL decreased by 2.26 μm per age perdecade. Conclusion: The Average RNFL thickness is 102.64 ± 9.56 μm in the Nepalese population. Gender and age related variation in the RNFL can serve as a useful guideline in the diagnosis of glaucoma in our population.
关键词： optic nerve head,retinal nerve fibre layer,optical coherence tomography
更新于2025-09-19 17:15:36
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Non-Invasive Quantification of the Growth of Cancer Cell Colonies by a Portable Optical Coherence Tomography
摘要： Investigation of tumor development is essential in cancer research. In the laboratory, living cell culture is a standard bio-technology for studying cellular response under tested conditions to predict in vivo cellular response. In particular, the colony formation assay has become a standard experiment for characterizing the tumor development in vitro. However, quantification of the growth of cell colonies under a microscope is difficult because they are suspended in a three-dimensional environment. Thus, optical coherence tomography (OCT) imaging was develop in this study to monitor the growth of cell colonies. Cancer cell line of Huh 7 was used and the cells were applied on a layer of agarose hydrogel, i.e., a non-adherent surface. Then, cell colonies were gradually formed on the surface. The OCT technique was used to scan the cell colonies every day to obtain quantitative data for describing their growth. The results revealed the average volume increased with time due to the formation of cell colonies day-by-day. Additionally, the distribution of cell colony volume was analyzed to show the detailed information of the growth of the cell colonies. In summary, the OCT provides a non-invasive quantification technique for monitoring the growth of the cell colonies. From the OCT images, objective and precise information is obtained for higher prediction of the in vivo tumor development.
关键词： cell culture,cell colonies,tumor spheroids,optical coherence tomography
更新于2025-09-19 17:15:36
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Sudden Occurrence of Roth Spots and Retinal Hemorrhages following Endoscopic Adhesiolysis: An SD-OCT Evaluation
摘要： Purpose: To document the occurrence of Roth spots and retinal hemorrhages by spectral-domain optical coherence tomography (SD-OCT) following endoscopic adhesiolysis for failed back surgery syndrome. Methods: Case report. Results: A 47-year-old patient noted progressive and bilateral visual loss immediately after epidural endoscopy and endoscopic adhesiolysis. Funduscopic examination showed multiple Roth spots and retinal hemorrhages at the posterior pole and the retinal midperiphery in both eyes. Spectral-domain optical coherence tomography demonstrated that Roth spots involved the inner retina, while dot hemorrhages involved the outer retina. Most retinal hemorrhages and Roth spots resolved over 6 weeks, with complete functional recovery in both eyes. However, SD-OCT revealed multiple areas of disruption of the outer retinal layers in the left eye. Conclusions: Roth spots and retinal hemorrhages can occur after endoscopic spinal surgery. Although hemorrhages resolve quickly over few weeks, SD-OCT can demonstrate that retinal damage might persist, especially in the outer retina. This finding may explain cases of incomplete recovery of visual function after complicated endoscopic adhesiolysis.
关键词： Endoscopic adhesiolysis,Optical coherence tomography,Roth spots,SD-OCT,Failed back surgery syndrome
更新于2025-09-19 17:15:36
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Do microvascular changes occur preceding neural impairment in early-stage diabetic retinopathy? Evidence based on the optic nerve head using optical coherence tomography angiography
摘要： Aims To evaluate the microvascular and neural differences of the optic nerve head (ONH) between type 2 diabetes mellitus (T2DM) subjects and controls. Methods This was a cross-sectional observational study. One hundred and eight eyes of 108 T2DM subjects with or without diabetic retinopathy (DR) (54 preclinical DR and 54 mild-to-moderate DR) were included. Fifty-two eyes of 52 healthy subjects were included as controls. The 4.5-mm Angio Disc scan mode and the ganglion cell complex scan mode were performed with all participants using AngioVue software 2.0 of the optical coherence tomography angiography (OCTA) device. Results Regarding ONH radial peripapillary capillary (RPC) density, the peripapillary region was mainly significantly reduced in the No-DR (NDR) group. Moreover, the RPC density of the peripapillary region and the inside optic disc area were significantly reduced in the non-proliferative DR (NPDR) group. When compared to the controls, significantly reduced peripapillary capillary density in six sections was observed in the NPDR group. However, reduced density was observed in only two sections in the NDR group. The NPDR group had significantly increased focal loss volume (FLV) and reduced peripapillary RNFL thickness in the inferior nasal section compared to those in the controls, but similar changes were not observed in the NDR group. A regression model identified RPCs inside the optic disc as a significant parameter in early-stage DR detection. In the NPDR group, BCVA showed a significantly negative correlation with RPCs inside the optic disc and a significantly positive correlation with FLV. Conclusions OCTA findings of the ONH area may provide evidence that microvascular changes occur preceding neural impairment in early-stage DR. However, further researches are still needed to support the statement. Reduced ONH perfusion inside the optic disc may be one of the crucial biomarkers in early-stage DR detection and is a possible sensitive visual acuity predictor in early-stage DR subjects. With the ONH mode, OCTA may be a more promising tool in DR screening.
关键词： Neural impairment,Optical coherence tomography angiography,Optic nerve head,Microvascular changes,Diabetic retinopathy
更新于2025-09-19 17:15:36
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Apport de la microscopie confocale par réflectance et de l’OCT dans le diagnostic d’un carcinome basocellulaire nodulaire kystique
摘要： The role of reflectance confocal microscopy and OCT in the diagnosis of nodular kystic BCC
关键词： Basal cell carcinoma,Noninvasive imaging,Optical coherence tomography,In vivo confocal microscopy,Dermoscopy,In vivo reflectance confocal microscopy,Cystic basal cell carcinoma
更新于2025-09-19 17:15:36