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Horizontal Extraocular Muscle and Scleral Anatomy in Children: A Swept-Source Anterior Segment Optical Coherence Tomography Study
摘要： Purpose: To evaluate the efficacy of anterior segment swept-source optical coherence tomography (SS-OCT) for examining horizontal extraocular muscle thickness, distance from the corneal limbus to the insertion of the horizontal extraocular muscle (limbus to insertion distance), and scleral thickness in Korean pediatric strabismus patients. Methods: This study included pediatric strabismus patients between 5 and 10 years of age. Children with any ocular disease other than strabismus or a history of ocular surgery were excluded. SS-OCT was used to measure horizontal extraocular muscle thickness, limbus to insertion distance, and scleral thickness. Eyes were classified into subgroups by sex, spherical equivalent of the refractive error (measured with cycloplegic refraction), and fixating/deviating eye. Results: One patient initially included in this study was excluded due to poor cooperation. Of the remaining 35 eyes of 20 patients, 19 eyes (54.3%) were from male patients and 16 eyes (45.7%) were from female patients. The mean patient age was 7.86 ± 1.38 years. Lateral scleral thickness was greater in male eyes than in female eyes (p = 0.048). No other differences were noted between male and female children. Additionally, there were no statistically significant differences between fixating and deviating eyes or among spherical equivalent groups for any parameter examined. Conclusions: Anterior segment SS-OCT can successfully and comfortably measure horizontal extraocular muscle and scleral anatomy in children. These measurements may be helpful for treatment and follow-up of pediatric strabismus patients.
关键词： Oculomotor muscle,Optical coherence tomography,Strabismus,Sclera,Pediatric ophthalmology
更新于2025-09-09 09:28:46
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Assessing the Anatomical and Functional Efficacy of Aflibercept on Wet ARMD: An OCT and Mferg Recording
摘要： Objective: To investigate the therapeutic efficacy of aflibercept on sub-foveal choroidal neovascularization due to Age-Related Macular Degeneration (ARMD). Methods: Fifteen patients (15 eyes) with sub-foveal choroidal neovascularization due to ARMD were treated with intravitreal aflibercept. The doses were monthly for the first three months, being repeated every three months after for one year, using 2 mg of intravitreal aflibercept. A total of six aflibercept injections were, finally, performed during the 12-month study. All patients underwent a complete ophthalmic examination, including the measurement of best-corrected visual acuity, fundus examination, intraocular pressure measurement, fluorescein angiography, optical coherence tomography (OCT) scan and multifocal electroretinography (mfERG) recording, at the baseline and at the first, second, third, sixth, ninth and 12th month after the first injection of aflibercept. Two masked examiners evaluated the visual acuity based on standard Snellen charts. Results: Fifteen patients (15 eyes), of mean age 69.2 ± 4.9 years old, with sub-foveal choroidal neovascularization due to ARMD were participated in this study. The mean BCVA was 0.12 ± 0.08, 0.20 ± 0.10, 0.25 ± 0.1, 0.28 ± 0.1, 0.34 ± 0.14, 0.36 ± 0.14 and 0.40 ± 0.14 decimal, at presentation, 1st, 2nd, 3rd, 6th, 9th and 12th month, respectively. Significant differences in amplitudes but not in latencies of three rings were observed over time. Significant reductions were noted among the central retinal thickness measurements before intravitreal aflibercept and at 1st, 2nd, 3rd, 6th, 9th and 12th month (465.0 ± 161.4, 374.9 ± 139.5, 323.3 ± 113.8, 290.3 ± 85, 263.3 ± 69, 243.0 ± 60.6 and 226.9 ± 63.5, respectively). Conclusion: This is the first time that anatomical and functional improvement of the macula in patients with sub-foveal choroidal neovascularization due to ARMD was shown objectively, based on OCT and mfERG recordings. In addition, the improvement of visual acuity was noted over time. Our study supports the fact that intravitreal use of aflibercept is safe and effective in treating sub-foveal choroidal neovascularization observed in patients with ARMD.
关键词： findings,electroretinography,Macular,Aflibercept,Anatomical,Sub-foveal,Multifocal,Optical coherence tomography,choroidal neovascularization,Function,Age-related macular degeneration
更新于2025-09-09 09:28:46
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Entanglement as the Symmetric Portion of Correlated Coherence
摘要： We show that the symmetric portion of correlated coherence is always a valid quantifier of entanglement, and that this property is independent of the particular choice of coherence measure. This leads to an infinitely large class of coherence based entanglement monotones, which is always computable for pure states if the coherence measure is also computable. It is already known that every entanglement measure can be constructed as a coherence measure. The results presented here show that the converse is also true. The constructions that are presented can also be extended to include more general notions of nonclassical correlations, leading to quantifiers that are related to quantum discord, thus providing an avenue for unifying all such notions of quantum correlations under a single framework.
关键词： coherence,entanglement,quantum correlations,quantum discord
更新于2025-09-09 09:28:46
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Wave Propagation Concepts for Near-Future Telecommunication Systems || Photon Propagation Through Dispersive Media
摘要： In the present chapter, we study the propagation of photons through dispersive media, starting from a description of the dynamics of free photons using a Dirac-like equation with an analysis of the energy solutions arising from this equation. A comparison with the case of a free electron is made. We present an analysis of the interaction between photons with the medium considering both a classical and a quantum treatment of light, and also we analyse the propagation of photons along a waveguide where they behave as if they did have a finite mass. As a technological application of the theoretical frame here presented, we consider the use of the properties of metamaterials to control the propagation of waves through waveguides filled with this kind of materials.
关键词： coherence,Hamiltonian,photon,wavefunction,dielectrics,metamaterials,antiparticle
更新于2025-09-09 09:28:46
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En Face Optical Coherence Tomography Imaging of the Photoreceptor Layers in Hydroxychloroquine Retinopathy
摘要： Objective: To investigate the application of en face optical coherence tomography (OCT) imaging in eyes with hydroxychloroquine (HCQ) retinopathy. Design: Retrospective case series Methods: Setting: Institutional Patient Population: Sixty-two eyes of 31 Asian patients with HCQ retinopathy. Observation Procedures: Macular volume scanning using swept-source OCT was performed in 6 × 6 and 9 × 9 mm areas centered on the fovea. Segmentation of the photoreceptor layers was automatically performed between the inner border of the ellipsoid zone and that of the retinal pigment epithelium-Bruch’s membrane complex to obtain en face OCT images. Findings from the en face images were qualitatively and quantitatively evaluated; they were analyzed and correlated with the fundus autofluorescence and visual field findings. Main Outcome Measures: En face OCT findings Results: All eyes with HCQ retinopathy had a beaten-bronze appearance in the areas with photoreceptor defects, whereas those with intact photoreceptors had areas with smooth surfaces, which were occasionally demarcated by hyporeflective margins, on the en face OCT images. The presence and extent of the retinopathy could be quickly determined using the images. They also provided quantitative information on the progression based on the areas of intact photoreceptors compared over several visits. Furthermore, the area of central intact photoreceptors significantly correlated with the mean deviation, pattern standard deviation, and visual field index of 30-2 visual field examinations (all P < .001). Conclusions: En face OCT may be useful for visualizing the presence and extent of HCQ retinopathy and its progression. The area of central intact photoreceptors measured on en face OCT images showed a significant association with functional visual field defects. This imaging may be a helpful adjunct for screening and follow-up examinations of HCQ retinopathy.
关键词： screening,en face optical coherence tomography,photoreceptor layers,progression,hydroxychloroquine retinopathy
更新于2025-09-09 09:28:46
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Color vision testing versus pattern visual evoked potentials and optical coherence tomography parameters in subclinical optic nerve involvement in multiple sclerosis
摘要： Acute idiopathic demyelinating optic neuritis is frequently the initial manifestation of multiple sclerosis (MS). We aimed to discuss the value of color vision testing to detect possible optic nerve involvement in patients with MS who had no history of optic neuritis. We evaluated color vision with Farnsworth-Munsell 100 (FM-100) hue test. Total error scores (TES), partial error scores for the red-green axis (RGS) and blue-yellow axis (BYS) were calculated. Topographic optic disc parameters (RNFL, RA, DA, CV, RV, and vertical C/D ratio), total macular volume (TMV), central macular thickness (CMT), and retinal ganglion cell layer (RGCL) were determined using spectral domain optical coherence tomography (SD-OCT). Choroidal thickness (CT) was measured using enhanced depth imaging optical coherence tomography (EDI-OCT). Pattern visual evoked potentials (PVEP) were also performed. Twenty-eight patients with RRMS (56 eyes) and 25 healthy controls (50 eyes) were included. P100 latencies were significantly delayed and P100 amplitudes were significantly reduced in the patient group compared with the controls (p (cid:1) 0.05). Statistically significant thinning was found in temporal quadrant in the patient group compared with the controls (p = 0.002). TES RGS, and BYS were all increased in the patient group but this was not statistically significant. We found no correlation between TES, RGS, BYS, and P100 latencies or OCT parameters. In our investigation as to whether color vision testing could be a simple biomarker for showing neurodegeneration of the anterior visual pathway regardless of optic neuritis, PVEP and OCT-assessed RNFL thickness seemed to be a more valuable biomarker than color vision testing.
关键词： Visual evoked potentials,Optical coherence tomography,Color vision,Multiple sclerosis,Subclinical optic neuritis,Retinal nerve fiber layer
更新于2025-09-09 09:28:46
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Collateral vessels on optical coherence tomography angiography in eyes with branch retinal vein occlusion
摘要： Aims To detect collateral vessels using optical coherence tomography angiography (OCTA) in eyes with branch retinal vein occlusion (BRVO) and to investigate the associations with visual outcomes and macular oedema. Methods Eyes with macular oedema secondary to BRVO that underwent OCTA at baseline and were followed up for more than 6 months were enrolled. The presence of collaterals, whether the collaterals were leaky or not, and the associations with visual outcomes and macular oedema were investigated. results Twenty-eight eyes of 28 patients (8 men and 20 women; mean age, 68 years) were enrolled. Collaterals were detected in 23 eyes (82%) and already existed at the initial visit. Collaterals were more frequently detected in eyes with major BRVO or ischaemic type. One-third of the collaterals were leaky and all of the leaky collaterals had microaneurysms (MAs) inside. Macular oedema in eyes with collaterals was more quickly and frequently resolved than that in eyes without collaterals, but there were no significant differences. Collateral vessel formation did not seem to impact on visual outcomes, but the mean baseline central retinal thickness (CRT) was significantly higher in eyes with collaterals, and the mean CRT reduction at 6 months after treatments was significantly greater than in eyes without collaterals. Conclusions These results suggest that collateral vessels are formed at the acute phase in eyes with BRVO. In addition, the presence of collaterals might be associated with absorption of macular oedema, but MAs formed in collaterals sometimes can cause macular oedema.
关键词： visual outcomes,collateral vessels,branch retinal vein occlusion,optical coherence tomography angiography,macular oedema
更新于2025-09-09 09:28:46
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Instant Stent-Accentuated Three-Dimensional Optical Coherence Tomography Guided Selection of Proper Distal Cell for Side Branch Dilatation in Bifurcation Stenting
摘要： In the bifurcation stenting, the distal rewiring for the side branch postdilatation confirmed by two-dimensional modalities may not lead to favorable results in some cases. If there are two distal cells divided by the link bridging from the carina, the rewiring through the larger distal cell may be recommended for the side branch postdilatation. Detailed confirmation of the rewired cell by the intraprocedural instant stent-accentuated three-dimensional optical coherence tomography is important.
关键词： distal rewiring,bifurcation stenting,side branch postdilatation,instant stent-accentuated 3D-OCT,three-dimensional optical coherence tomography
更新于2025-09-09 09:28:46
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Visible-light optical coherence tomography-based multimodal system for quantitative fundus autofluorescence imaging
摘要： Fundus autofluorescence (FAF) imaging is commonly used in ophthalmic clinics for diagnosis and monitoring of retinal diseases. Lipofuscin in the retinal pigment epithelium (RPE), with A2E as its most abundant component and a visual cycle by-product, is the major fluorophore of FAF. Lipofuscin accumulates with age and is implicated in degenerative retinal diseases. The amount of lipofuscin in RPE can be assessed by quantitative measurement of FAF. However, the currently available FAF imaging technologies are not capable of quantifying the absolute intensity of FAF, which is essential for comparing images from different individuals, and from the same individual over time. One major technical difficulty is to compensate the signal attenuation by ocular media anterior to the RPE (pre-RPE media). FAF intensity is also influenced by fluctuations in imaging conditions such as illumination power and detector sensitivity, all of which need to be compensated. In this review, we present the concept and research progress of using visible-light optical coherence tomography-based simultaneous multimodal retinal imaging to compensate signal attenuation by pre-RPE media and the influence of parameters of the acquisition system for accurate measurement of FAF intensities.
关键词： fundus autofluorescence imaging,multimodal imaging,retinal pigment epithelium lipofuscin,Visible-light optical coherence tomography,retinal imaging,fluorescence quantification
更新于2025-09-09 09:28:46
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Parameters of ocular fundus on spectral-domain optical coherence tomography for glaucoma diagnosis
摘要： In this review, we summarize the progression of several parameters assessed by spectral-domain optical coherence tomography (SD-OCT) in recent years for the detection of glaucoma. Monitoring the progression of defects in the retinal nerve fiber layer (RNFL) thickness is essential. Imaging and analysis of retinal ganglion cells (RGCs) and inner plexiform layer (IPL), respectively, have been of great importance. Optic nerve head (ONH) topography obtained from 3D SD-OCT images is another crucial step. Other important assessments involve locating the Bruch’s membrane opening (BMO), estimating the optic disc size and rim area, and measuring the lamina cribrosa displacement. Still other parameters found in the past three years for glaucoma diagnosis comprise central retinal artery resistive index, optic disc perfusion in optical coherence tomography angiography (OCTA) study, peripapillary choroidal thickness, and choroidal area in SD-OCT. Recently, several more ocular fundus parameters have been found, and compared with the earlier parameters to judge the accuracy of diagnosis. While a few of these parameters have been widely used in clinical practice, a fair number are still in the experimental stage.
关键词： optic nerve head,retinal nerve fiber layer,lamina cribrosa,optical coherence tomography,macular thickness,ganglion cells,glaucoma progression
更新于2025-09-09 09:28:46