1. Articles from iovs.org

  2. 241-264 of 532 « 1 2 ... 8 9 10 11 12 13 14 ... 21 22 23 »
    1. Effect of Spectrum Bias on the Diagnostic Accuracy of Spectral-Domain Optical Coherence Tomography in Glaucoma

      Effect of Spectrum Bias on the Diagnostic Accuracy of Spectral-Domain Optical Coherence Tomography in Glaucoma

      Purpose. To evaluate the influence of a control group on the diagnostic accuracy of spectral-domain optical coherence tomography (SD-OCT) in early glaucoma. Methods. In a diagnostic, case–control study, 119 eyes of 60 normal subjects with no findings suspicious for glaucoma (control cohort 1); 76 eyes of 41 subjects referred by general ophthalmologists as glaucoma suspects based on optic disc morphology, but found by glaucoma experts to be normal but with physiological variations in their optic nerves (control cohort 2); and 65 eyes of 46 early-glaucoma patients (cases) underwent imaging of the optic nerve head (ONH), retinal nerve fiber layer ...

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    2. Relationships among Multifocal Electroretinogram Amplitude, Visual Field Sensitivity, and SD-OCT Receptor Layer Thicknesses in Patients with Retinitis Pigmentosa

      Relationships among Multifocal Electroretinogram Amplitude, Visual Field Sensitivity, and SD-OCT Receptor Layer Thicknesses in Patients with Retinitis Pigmentosa

      Purpose. To compare local functional measures, the multifocal electroretinogram (mfERG) and visual field sensitivity, with a local structural measure, spectral domain (SD) optical coherence tomography (OCT), of receptor damage in patients with retinitis pigmentosa (RP). Methods. MfERGs, visual fields, and SD-OCT scans were obtained from 10 patients with RP, ranging in age from 23 to 59 years. Average amplitudes, average linear sensitivities, and average layer thicknesses were measured from within the central 3° and from three concentric annuli located between 3° and 8°, 8° and 15°, and 15° and 24°. A computer program aided manual segmentation and calculated OCT thickness ...

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    3. Spontaneous Ocular and Neurologic Deficits in Transgenic Mouse Models of Multiple Sclerosis and Noninvasive Investigative Modalities: A Review

      Spontaneous Ocular and Neurologic Deficits in Transgenic Mouse Models of Multiple Sclerosis and Noninvasive Investigative Modalities: A Review

      Multiple sclerosis (MS) is an autoimmune, inflammatory, neurodegenerative, demyelinating disease of the central nervous system, predominantly involving myelinated neurons of the brain, spinal cord, and optic nerve. Optic neuritis is frequently associated with MS and often precedes other neurologic deficits associated with MS. A large number of patients experience visual defects and have abnormalities concomitant with neurologic abnormalities. Transgenic mice manifesting spontaneous neurologic and ocular disease are unique models that have revolutionized the study of MS. Spontaneous experimental autoimmune encephalomyelitis (sEAE) presents with spontaneous onset of demyelination, without the need of an injectable immunogen. This review highlights the various models ...

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      Mentions: Richard K. Lee
    4. Optical Coherence Tomographic Reflectivity of Photoreceptors beneath Cystoid Spaces in Diabetic Macular Edema

      Optical Coherence Tomographic Reflectivity of Photoreceptors beneath Cystoid Spaces in Diabetic Macular Edema

      Purpose: To investigate the relationship between the cystoid spaces in the outer plexiform layer (OPL) and the characteristics of the photoreceptors beneath the cystoid spaces in patients with diabetic macular edema (DME). Methods: In this observational cross-sectional study, we retrospectively reviewed consecutive 123 eyes of 96 patients with clinically significant macular edema, and investigated the characteristics of the photoreceptors on optical coherence tomography (OCT) images represented by the external limiting membrane (ELM) and the junction between inner and outer segments (IS/OS), and their association with the overlying cystoid spaces. Results: The areas beneath the cystoid spaces in the OPL ...

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    5. Spectral-Domain Optical Coherence Tomography of β-zone Peripapillary Atrophy: Influence of Myopia and Glaucoma

      Spectral-Domain Optical Coherence Tomography of β-zone Peripapillary Atrophy: Influence of Myopia and Glaucoma

      Purpose: To investigate the influence of glaucoma and myopia on the cross-sectional configuration of β-zone peripapillary atrophy (PPA-β) using spectral-domain optical coherence tomography (SD-OCT). Methods: Among 100 eyes of 100 consecutive patients with POAG regardless of intraocular pressure level and 100 eyes of 100 normal subjects, cross-sectional B-scan images of PPA-β obtained with SD-OCT were evaluated. PPA bed configurations were classified and associated factors were studied with multivariate analysis. Results: In 147 eyes with PPA-β (84 POAG and 63 normal eyes; P = 0.0012), PPA bed were composed of straight (14 POAG and 27 normal eyes) or downward-curved (19 and ...

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    6. Automated Assessment of Drusen Using Three-dimensional Spectral-domain Optical Coherence Tomography

      Automated Assessment of Drusen Using Three-dimensional Spectral-domain Optical Coherence Tomography

      Purpose: To compare automated assessment of macular drusen delineated by our originally-developed algorithm on 3-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) with the assessment by certificated graders on color fundus photographs in non-neovascular age-related macular degeneration (AMD). Design: Prospective case series. Methods: Automated assessment of macular drusen was performed using raster scan by 3D OCT-1000 (Topcon) in 18 eyes with non-neovascular AMD with at least one large druse (≥125μm) and predominantly soft indistinct drusen. We defined drusen as the regions that have the distance between the RPE and calculated Bruch's membrane lines > predefined threshold distances. We assessed the agreement ...

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    7. Three-Dimensional Evaluation of the Lamina Cribrosa Using Spectral-Domain Optical Coherence Tomography in Glaucoma

      Three-Dimensional Evaluation of the Lamina Cribrosa Using Spectral-Domain Optical Coherence Tomography in Glaucoma
      Purpose. To introduce a novel, digital, three-dimensional (3D) reconstruction of the optic nerve head (ONH) and to use this method to evaluate the 3D configuration of the lamina cribrosa (LC) in patients with primary open-angle glaucoma. Methods. Optic discs of 137 eyes of 137 patients with open-angle glaucoma were scanned with enhanced depth-imaging spectral domain-optical coherence tomography (SD-OCT). 3D images of the ONH were then reconstructed from B-scan images using maximum intensity projection (MIP) and texture-based volume rendering (VRT). The performance of the threshold segmentation by MIP and VRT was assessed by comparing the distance of the anterior LC surface ...
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    8. Diurnal Variation of Choroidal Thickness in Normal, Healthy Subjects Measured by Spectral Domain Optical Coherence Tomography

      Diurnal Variation of Choroidal Thickness in Normal, Healthy Subjects Measured by Spectral Domain Optical Coherence Tomography
      Purpose. To describe the pattern and magnitude of diurnal variation of choroidal thickness (CT), its relation to systemic and ocular factors, and to determine the intervisit reproducibility of diurnal patterns. Methods. A prospective study was conducted on 12 healthy volunteers who each underwent sequential ocular imaging on two separate days at five fixed, 2-hour time intervals. Spectral domain optical coherence tomography (OCT) with enhanced depth imaging and image tracking was performed using a standardized protocol. Choroidal and retinal thicknesses were independently assessed by two masked graders. CT diurnal variation was assessed using repeated-measures ANOVA. Results. A significant diurnal variation in ...
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    9. Spectral-Domain Optical Coherence Tomography Enhanced Depth Imaging of the Normal and Glaucomatous Nonhuman Primate Optic Nerve Head

      Spectral-Domain Optical Coherence Tomography Enhanced Depth Imaging of the Normal and Glaucomatous Nonhuman Primate Optic Nerve Head
      Purpose. To test whether the enhanced depth imaging (EDI) modality improves anterior and posterior lamina cribrosa surface (ALCS and PLCS) visibility compared with conventional spectral-domain optical coherence tomography (SD-OCT). Methods. Conventional and EDI SD-OCT scans were obtained 30 minutes after IOP was manometrically lowered to 10 mm Hg in both eyes of 14 nonhuman primates (NHPs) with unilateral experimental glaucoma (EG). Thirteen horizontal and seven vertical radial B-scans of each SD-OCT data set were delineated by one operator masked to image type. Delineated ALCS and PLCS points were projected to 1 of 100 equal-sized subregions of the neural canal opening ...
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    10. Assessment of Differential Pharmacodynamic Effects using Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration

      Assessment of Differential Pharmacodynamic Effects using Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration

      Purpose: To assess the differential pharmacodynamic effects of bevacizumab (Avastin), pegaptanib (Macugen), and verteporfin photodynamic therapy (PDT), using novel OCT parameters, in a recently completed phase III/IV clinical trial. Methods: Data from 122 patients participating in the Avastin (Bevacizumab) for Choroidal neovascularization (ABC) trial, were evaluated. Stratus OCT images were analyzed using custom software - changes in volume of the neurosensory retina, subretinal fluid (SRF), pigment epithelium detachment (PED), and subretinal tissue, were calculated over the 54-week trial period. Results: Reductions in retinal oedema were more than twice as great from bevacizumab than pegaptanib (-0.82 mm3 versus -0.31 ...

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    11. Analysis of progression of reticular pseudodrusen by spectral domain optical coherence tomography

      Analysis of progression of reticular pseudodrusen by spectral domain optical coherence tomography

      Purpose: To analyze reticular pseudodrusen progression using SD-OCT. Methods: Thirty-three consecutive patients (48 eyes) underwent Spectralis SD-OCT using the eye-tracked follow-up protocol 24+/-2 months after baseline examination. Each pair of B-scans (only 1 per eye was evaluated among those showing pseudodrusen progression) was compared with respect to pseudodrusen appearance and retinal layers structure. Stage 1 pseudodrusen was defined as granular material between the RPE and the IS/OS, stage 2 as mounds of material sufficient to alter the contour of the IS/OS, stage 3 as thicker material adopting a conical appearance and breaking through the IS/OS, and ...

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    12. The physiological variation of the retinal nerve fibre layer thickness and macular volume in humans as assessed by spectral-domain optical coherence tomography

      The physiological variation of the retinal nerve fibre layer thickness and macular volume in humans as assessed by spectral-domain optical coherence tomography
      Purpose With the introduction of spectral domain optical coherence tomography (SD-OCT), changes in the retinal nerve fibre layer (RNFL) thickness and macular volume (MV) can be detected with a high precision. This study aimed to determine whether there is a physiological quantifiable degree of variation of these structures in humans. Methods This study took place during a 10 km charity run at VU University Amsterdam. Weight, height, hydration status, RNFL thickness (ring scan,12 degrees around the optic nerve head) and MV (20x20 degrees) were assessed in all 69 subjects (44 runners, 25 controls) using the Heidelberg Spectralis with eye-tracking ...
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    13. Optical coherence tomography as a rapid, accurate, non-contact method of visualizing the palisades of Vogt

      Optical coherence tomography as a rapid, accurate, non-contact method of visualizing the palisades of Vogt
      Purpose: This study explored the efficacy of Optical Coherence Tomography (OCT) as a high-resolution, non-contact method for imaging of the palisades of Vogt by correlating OCT and confocal microscopy images. Methods: Human limbal rims were acquired and imaged with OCT and confocal microscopy. The area of the epithelial basement membrane in each of these sets was digitally reconstructed and the models were compared. Results: OCT identified the palisades within the limbus and exhibited excellent structural correlation with immunostained tissue imaged by confocal microscopy. Conclusions: OCT successfully identified the limbal palisades of Vogt that constitute the corneal epithelial stem cell niche ...
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    14. Topographic variation and interocular symmetry of macular choroidal thickness using enhanced depth imaging optical coherence tomography

      Topographic variation and interocular symmetry of macular choroidal thickness using enhanced depth imaging optical coherence tomography

      Purpose: To report and analyse factors influencing topographical and interocular variations of choroidal thickness (CT) in healthy adult population. Methods: 100 eyes of 50 healthy subjects underwent visual acuity and axial length measurements and optical coherence tomography with enhanced depth imaging using the Heidelberg Spectralis HRA+OCT. CT at the fovea, and 3 mm nasal, temporal, superior and inferior to the fovea were measured manually. Topographic variation, relative interocular differences in CT and predictors of CT were analysed. The relationship between interocular differences in CT, age and interocular axial length differences was explored. Results: The mean (SD) foveal CT in ...

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    15. Validated Automatic Segmentation of AMD Pathology Including Drusen and Geographic Atrophy in SD-OCT Images

      Validated Automatic Segmentation of AMD Pathology Including Drusen and Geographic Atrophy in SD-OCT Images
      Purpose. To automatically segment retinal spectral domain optical coherence tomography (SD-OCT) images of eyes with age-related macular degeneration (AMD) and various levels of image quality to advance the study of retinal pigment epithelium (RPE)+drusen complex (RPEDC) volume changes indicative of AMD progression. Methods. A general segmentation framework based on graph theory and dynamic programming was used to segment three retinal boundaries in SD-OCT images of eyes with drusen and geographic atrophy (GA). A validation study for eyes with nonneovascular AMD was conducted, forming subgroups based on scan quality and presence of GA. To test for accuracy, the layer thickness ...
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    16. Trans-synaptic retinal degeneration in optic neuropathies: Optical Coherence Tomography study

      Trans-synaptic retinal degeneration in optic neuropathies: Optical Coherence Tomography study
      Purpose. Recently demonstrated neuronal loss in the inner nuclear layer of the retina in multiple sclerosis (MS) and glaucoma raises the question of a primary (possibly immune-mediated) or secondary (trans-synaptic) mechanism of retinal damage in these diseases. In the present study we used Optical Coherence Tomography to investigate retrograde retinal trans-synaptic degeneration in patients with long-standing and severe loss of ganglion cells due to optic neuropathy. Methods. Ten eyes of glaucoma patients with visual field defect limited to upper hemifield and 10 eyes of MS patients with previous episode of optic neuritis (ON) and extensive loss of ganglion cells were ...
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    17. Noninvasive Imaging of the Foveal Avascular Zone with High-Speed, Phase-Variance Optical Coherence Tomography

      Noninvasive Imaging of the Foveal Avascular Zone with High-Speed, Phase-Variance Optical Coherence Tomography

      Purpose. To demonstrate the application of phase-variance optical coherence tomography (pvOCT) for contrast agent–free in vivo imaging of volumetric retinal microcirculation in the human foveal region and for extraction of foveal avascular zone dimensions. Methods. A custom-built, high-speed Fourier-domain OCT retinal imaging system was used to image retinas of two healthy subjects and eight diabetic patients. Through the acquisition of multiple B-scans for each scan location, phase differences between consecutive scans were extracted and used for phase-variance contrast, identifying motion signals from within blood vessels and capillaries. The en face projection view of the inner retinal layers segmented out ...

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    18. Dynamic changes in anterior segment (AS) parameters in eyes with primary angle closure (PAC) and PAC glaucoma and open-angle eyes assessed using AS optical coherence tomography

      Dynamic changes in anterior segment (AS) parameters in eyes with primary angle closure (PAC) and PAC glaucoma and open-angle eyes assessed using AS optical coherence tomography

      Purpose: To evaluate serial changes in anterior segment (AS) parameters in terms of variation in pupil diameter (PD) using AS optical coherence tomography (OCT) in eyes with primary angle closure or primary angle closure glaucoma (PCG), age-matched open-angle (AO) eyes, and young open-angle (YO) eyes. Methods: Forty-four PCG (mean±standard deviation; 62.2 ± 7.5 years ), 36 AO (62.0 ± 12.3 years), and 58 YO eyes (29.1 ± 7.0 years) were imaged under four standardized lighting conditions (3.25, 100.8, 426, and 1420 cd/m2). PD, anterior chamber depth (ACD), iris cross-sectional area (IA), iris thicknesses at ...

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    19. 2-D Pattern of Nerve Fiber Bundles in Glaucoma Emerging from Spectral-Domain Optical Coherence Tomography

      2-D Pattern of Nerve Fiber Bundles in Glaucoma Emerging from Spectral-Domain Optical Coherence Tomography
      Purpose: To correlate the thicknesses of focal regions of the macular ganglion cell layer with those of the peripapillary nerve fiber layer using spectral-domain optical coherence tomography (SD-OCT) in glaucoma subjects. Methods: Macula and optic-nerve-head SD-OCT volumes were obtained in 57 eyes of 57 subjects with open-angle glaucoma or glaucoma suspicion. Using a custom automated computer algorithm, the thickness of 66 macular ganglion cell layer regions and the thickness of 12 peripapillary nerve fiber layer regions were measured from registered SD-OCT volumes. The mean thickness of each ganglion-cell-layer region was correlated to the mean thickness of each peripapillary-nerve-fiber-layer region across ...
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    20. Imaging Retrobulbar Subarachnoid Space around Optic Nerve by Swept-Source Optical Coherence Tomography in Eyes with Pathologic Myopia

      Imaging Retrobulbar Subarachnoid Space around Optic Nerve by Swept-Source Optical Coherence Tomography in Eyes with Pathologic Myopia
      Purpose. To examine the subarachnoid space (SAS) of eyes with pathologic myopia and analyze the characteristics of the SAS and the surrounding tissues by swept-source optical coherence tomography (OCT). Methods. One hundred thirty-three eyes of 76 patients with pathologic myopia (spherical equivalent refractive error of >−8.00 diopters (D) or an axial length >26.5 mm) and 32 eyes of 32 subjects with emmetropia were enrolled. The eyes in both groups were not tested to determine whether glaucoma was present. The papillary and peripapillary areas were examined with a swept-source OCT prototype system that uses a wavelength sweeping laser operated ...
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    21. 3-Dimensional Evaluation of the Lamina Cribrosa Using Spectral Domain Optical Coherence Tomography in Glaucoma

      3-Dimensional Evaluation of the Lamina Cribrosa Using Spectral Domain Optical Coherence Tomography in Glaucoma
      Purpose: To introduce a novel, digital 3-dimensional (3D) reconstruction of the optic nerve head (ONH) and to evaluate the 3D configuration of the lamina cribrosa (LC) in patients with primary open angle glaucoma using this method. Methods: Optic discs of 137 eyes of 137 patients with open angle glaucoma were scanned with enhanced depth imaging spectral domain-optical coherence tomography (SD-OCT). 3D images of the ONH then were reconstructed from B scan images using maximum intensity projection (MIP) and texture based-volume rendering (VRT). The performance of the threshold segmentation by MIP and VRT was assessed by comparing the distance of the ...
      Read Full Article
    22. Diurnal variation of choroidal thickness in normal, healthy subjects

      Diurnal variation of choroidal thickness in normal, healthy subjects
      Purpose: To describe the pattern and magnitude of diurnal variation of choroidal thickness (CT), its relation to systemic and ocular factors, and to determine the inter-visit reproducibility of diurnal patterns. Methods: A prospective study was conducted on 12 healthy volunteers who each underwent sequential ocular imaging on 2 separate days at 5 fixed, two-hourly time intervals. Spectral Domain Optical Coherence Tomography (OCT) with Enhanced Depth Imaging and image tracking was performed using a standardized protocol. Choroidal and retinal thicknesses were independently assessed by 2 masked graders. CT diurnal variation was assessed using repeated measures Analysis of Variance (ANOVA). Results: A ...
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    23. Spectral Domain Optical Coherence Tomography (SDOCT) Enhanced Depth Imaging (EDI) of the Normal and Glaucomatous Non-human Primate (NHP) Optic Nerve Head (ONH)

      Spectral Domain Optical Coherence Tomography (SDOCT) Enhanced Depth Imaging (EDI) of the Normal and Glaucomatous Non-human Primate (NHP) Optic Nerve Head (ONH)
      Purpose: To test whether the EDI modality improves anterior and posterior lamina cribrosa surface (ALCS and PLCS) visibility compared to conventional SDOCT. Methods: Conventional and EDI SDOCT scans were obtained 30 minutes after IOP was manometrically lowered to 10 mmHg in both eyes of 14 non-human primates (NHPs) with unilateral experimental glaucoma (EG). Thirteen horizontal and 7 vertical radial B-scans of each SDOCT data set were delineated by one operator masked to image type. Delineated ALCS and PLCS points were projected to one of 100 equal-sized sub-regions of the neural canal opening (NCO) reference plane and the number of delineated ...
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    241-264 of 532 « 1 2 ... 8 9 10 11 12 13 14 ... 21 22 23 »
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