1. Articles from iovs.org

  2. 241-264 of 587 « 1 2 ... 8 9 10 11 12 13 14 ... 23 24 25 »
    1. Laminar Displacement and Prelaminar Tissue Thickness Change after Glaucoma Surgery Imaged with Optical Coherence Tomography

      Laminar Displacement and Prelaminar Tissue Thickness Change after Glaucoma Surgery Imaged with Optical Coherence Tomography

      Purpose: To study changes in lamina cribrosa position and prelaminar tissue thickness (PTT) after surgical intraocular pressure (IOP) reduction in glaucoma patients. Methods: Twenty-two patients (mean age, 71.4 years) were imaged with spectral domain optical coherence tomography (SD-OCT, 24 radial B-scans centered on the optic nerve head) before trabeculectomy or tube shunt implantation. Follow-up images were acquired 1 week, 1 month, 3 and 6 months post-surgery. Bruch's membrane opening (BMO), the internal limiting membrane (ILM) and the anterior laminar surface (ALS) were segmented with custom software. Surfaces were fitted to the ILM and ALS with the extracted 3D ...

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    2. A Novel Technique of Adjusting Segmentation Boundary Layers to Achieve Comparability of Retinal Thickness and Volumes between Spectral Domain and Time Domain OCT

      A Novel Technique of Adjusting Segmentation Boundary Layers to Achieve Comparability of Retinal Thickness and Volumes between Spectral Domain and Time Domain OCT

      Purpose: The quantitative assessment of retinal thickness and volume varies according to the Optical Coherence Tomography (OCT) machine used due to differences in segmentation lines. We describe a novel method of adjusting the segmentation lines of spectral-domain OCT (SD-OCT) to enable comparison with time-domain OCT (TD-OCT), and assess factors affecting its accuracy. Methods: In a prospective study, SD-OCT (Spectralis OCT) and TD-OCT (Stratus OCT) were sequentially performed on 200 eyes of 100 healthy individuals. Central retinal thickness (CRT), central point thickness (CPT) and 1mm volume of the ETDRS grid were compared between the 2 machines. The segmentation lines on SD-OCT ...

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    3. Comparison of two spectral domain optical coherence tomography devices for angle closure assessment

      Comparison of two spectral domain optical coherence tomography devices for angle closure assessment

      Purpose. To compare two spectral domain optical coherence tomography (SD-OCT) devices for the identification of angle structures and the presence of angle closure Methods. This was a prospective comparative study. Consecutive patients underwent gonioscopy and anterior segment imaging using 2 SD-OCT devices (iVue [Optovue Corporation, Fremont, Ca] and Cirrus [Carl Zeiss Meditec, Dublin, Ca]). Images were evaluated for the ability to detect angle structures such as Schwalbe's line (SL), trabecular meshwork (TM), Schlemm's canal (SC), and scleral spur (SS); and the presence of angle closure. Angle closure was defined as iris contact with the angle wall anterior to ...

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    4. Quantifying Structures in the Ocular Fundus

      Quantifying Structures in the Ocular Fundus

      Moghimi et al. showed that Heidelberg retinal tomography (HRT) and one brand of spectral domain optical coherence tomography (SD-OCT) do not give the same measurement of disc and neuro-retinal rim areas within the disc (http://dx.doi.org/10.1167/iovs.11-8362).1 The measurements correspond better with an attempt to correct for optical magnification (by taking into account axial length of the eye). However, the definition of “the edge of the disc,” which enters into calculations of the disc area and rim area, is not the same for these two instruments. It often is a boundary defined as the ...

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    5. Reproducibility of Macular, Retinal Nerve Fiber Layer, and ONH Measurements by OCT in Rhesus Monkeys: The Beijing Intracranial and Intraocular Pressure (iCOP) Study

      Reproducibility of Macular, Retinal Nerve Fiber Layer, and ONH Measurements by OCT in Rhesus Monkeys: The Beijing Intracranial and Intraocular Pressure (iCOP) Study

      Purpose. We evaluated repeatability and reproducibility of measurements of the retinal nerve fiber layer thickness (RNFLT), optic nerve head (ONH), and macular inner retinal layer (MIRL) by RTVue spectral-domain optical coherence tomography (OCT) in normal Rhesus monkeys. Methods. The experimental study included 15 adult Rhesus macaque monkeys. RNFLT, ONH parameters (area of disc, cup, and rim; volume of cup and rim; and cup-to-disc ratios), and MIRL thickness were imaged at three separate examinations within one month. Each eye was imaged three times at the first examination, and once at each of the two following examinations. We determined the intra-session and ...

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    6. Patterns of Ganglion Cell Complex and Nerve Fiber Layer Loss in Nonarteritic Ischemic Optic Neuropathy by Fourier-Domain Optical Coherence Tomography

      Patterns of Ganglion Cell Complex and Nerve Fiber Layer Loss in Nonarteritic Ischemic Optic Neuropathy by Fourier-Domain Optical Coherence Tomography

      Purpose. To characterize by Fourier-domain optical coherence tomography (FD-OCT) the loss of nerve fiber layer (NFL) and ganglion cell complex (GCC) in nonarteritic ischemic optic neuropathy (NAION). Methods. Patients diagnosed with NAION were enrolled and categorized into “superior field loss (SFL),” “inferior field loss (IFL),” and “bihemispheric field loss (BFL)” groups based on the Swedish interactive threshold algorithm 30‐2 achromatic visual field (VF) tests. Six months after presentation, they were scanned by FD-OCT to map peripapillary NFL and macular GCC thicknesses. Age-matched normals were selected from participants in the Advanced Imaging for Glaucoma Study (www.AIGStudy.net). Deviation maps ...

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    7. Assessment of Macular Function for Idiopathic Epiretinal Membranes Classified by Spectral-Domain Optical Coherence Tomography

      Assessment of Macular Function for Idiopathic Epiretinal Membranes Classified by Spectral-Domain Optical Coherence Tomography

      Purpose. To evaluate the functional changes in various morphologic types of idiopathic epiretinal membrane (ERM) by multifocal electroretinography (mfERG) and spectral-domain optical coherence tomography (SD-OCT). Methods. All patients (n = 71) with unilateral idiopathic ERM underwent complete ophthalmologic examination, including measurements of best-corrected visual acuity (BCVA), SD-OCT, and mfERG for both eyes. To classify idiopathic ERM by subtype, the morphologic characteristics of the foveal area on representative scanned images were assessed. The five subtypes by foveal SD-OCT morphology included fovea-attached ERM with outer retinal thickening and minimal inner retinal change (Group 1A), outer retinal inward projection and inner retinal thickening (Group ...

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    8. Does optic nerve head size variation affect circumpapillary retinal nerve fiber layer thickness measurement by optical coherence tomography?

      Does optic nerve head size variation affect circumpapillary retinal nerve fiber layer thickness measurement by optical coherence tomography?

      Purpose: To determine the relationship between retinal nerve fiber layer (RNFL) thickness, optic disc size and image magnification. Methods: The cohort consisted of 196 normal eyes of 101 participants in the Advanced Imaging for Glaucoma Study (AIGS), a multi-center, prospective, longitudinal study to develop advanced imaging technologies for glaucoma diagnosis. Scanning laser tomography (HRT II) was used to measure disc size. Optical coherence tomography (Stratus) was used to perform circumpapillary RNFL thickness measurements using the standard fixed 3.46 mm nominal scan diameter. A theoretical model of magnification effects was developed to relate RNFL thickness (overall average) with axial length ...

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    9. Anterior Chamber Dimensions and Posterior Corneal Arc Length in Malay Eyes: An Anterior segment Optical Coherence Tomography Study

      Anterior Chamber Dimensions and Posterior Corneal Arc Length in Malay Eyes: An Anterior segment Optical Coherence Tomography Study

      Purpose: To provide normative data of corneal and anterior segment dimensions and a novel parameter, PCAL, in an adult Malay population. Methods: The current analysis is a sub-study of the Singapore Malay Eye Study (SiMES), a cross-sectional, population-based study of urban Malays aged 40-80 years. Subjects underwent ophthalmic and systemic examination, including imaging with anterior segment optical coherence tomography (AS-OCT). Ocular parameters were subsequently measured with the Zhongshan Assessment Program (ZAP): Anterior chamber depth (ACD), central corneal thickness (CCT), anterior and posterior corneal curvature (ACC and PCC), and posterior corneal arc length (PCAL), which is a novel parameter defined as ...

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    10. Theoretical, Experimental, and Optical Coherence Tomography (OCT) Studies of Graft Apposition and Adhesion in Descemets Stripping Automated Endothelial Keratoplasty (DSAEK)

      Theoretical, Experimental, and Optical Coherence Tomography (OCT) Studies of Graft Apposition and Adhesion in Descemets Stripping Automated Endothelial Keratoplasty (DSAEK)

      Purpose. To investigate the effects of adhesion promoting surgical adjuncts in Descemets stripping automated endothelial keratoplasty (DSAEK). The effects of air-fill pressure, duration, use of venting incisions and stromal roughening on fluid dispersion, and donor adhesion strength were examined in theoretical, optical coherence tomography (OCT), and strain gauge models of DSAEK. Methods. OCT analysis: DSAEK modeled using a microkeratome prepared lenticule inserted under a “recipient” corneo-scleral rim mounted on an artificial anterior chamber. Pressure of 18 mm Hg (n = 6) or 60 mm Hg (n = 6) was applied. The area of interface fluid was measured sequentially. The area of interface ...

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    11. Time Course of Changes in Metamorphopsia, Visual Acuity, and OCT Parameters after Successful Epiretinal Membrane Surgery

      Time Course of Changes in Metamorphopsia, Visual Acuity, and OCT Parameters after Successful Epiretinal Membrane Surgery

      Purpose. To follow the changes in the metamorphopsia, visual acuity, and OCT parameters after epiretinal membrane (ERM) removal. Methods. The study included 49 eyes of 49 patients with an ERM who underwent vitrectomy and membrane peeling. The changes in the best-corrected visual acuity (BCVA), metamorphopsia, and central foveal thickness (CFT) were evaluated at baseline and 1, 3, 6, 9, and 12 months postoperatively. M-CHARTS were used to quantify metamorphopsia. Results. The mean BCVA, metamorphopsia scores for horizontal lines (MH) and vertical lines (MV), and CFT improved significantly at 12 months after surgery (P < 0.001). The baseline BCVA, MH score ...

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    12. Wide 3-Dimensional Macular Ganglion Cell Complex Imaging with Spectral-Domain Optical Coherence Tomography in Glaucoma

      Wide 3-Dimensional Macular Ganglion Cell Complex Imaging with Spectral-Domain Optical Coherence Tomography in Glaucoma

      Purpose: To determine whether measurement of ganglion cell complex (GCC) thickness over a wide area (8-mm diameter) can improve the glaucoma-discriminating ability of spectral-domain optical coherence tomography (SD-OCT) compared to that in the standard macular area (6-mm diameter). Methods: Ninety-three subjects were enrolled, including 46 healthy eyes of 46 volunteers and 47 eyes of 47 glaucoma patients (23 eyes with preperimetric glaucoma [PPG] and 24 eyes with early glaucoma [EG]). All patients underwent SD-OCT raster scanning over a 9 mm × 9 mm square area centered on the fovea. Areas under the receiver operating characteristic curves (AROCs) were compared between wide ...

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    13. Patterns of Ganglion Cell Complex and Nerve Fiber Layer Loss in Non-Arteritic Ischemic Optic Neuropathy by Fourier-Domain Optical Coherence Tomography

      Patterns of Ganglion Cell Complex and Nerve Fiber Layer Loss in Non-Arteritic Ischemic Optic Neuropathy by Fourier-Domain Optical Coherence Tomography

      Purpose: To characterize by Fourier-domain optical coherence tomography (FD-OCT) the loss of nerve fiber layer (NFL) and ganglion cell complex (GCC) in non-arteritic ischemic optic neuropathy (NAION). Methods: Patients diagnosed with NAION were enrolled and categorized into "superior field loss (SFL)," "inferior field loss (IFL)," and "bihemispheric field loss (BFL)" groups based on the Swedish interactive threshold algorithm 30-2 achromatic visual field (VF) tests. Six months after presentation, they were scanned by FD-OCT to map peripapillary NFL and macular GCC thicknesses. Age-matched normals were selected from participants in the Advanced Imaging for Glaucoma Study (www.AIGStudy.net). Deviation maps were ...

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    14. En face enhanced depth imaging optical coherence tomography of fibrovascular pigment epithelium detachment

      En face enhanced depth imaging optical coherence tomography of fibrovascular pigment epithelium detachment

      Purpose:To analyze the internal structure of fibrovascular pigment epithelial detachment (FV-PED) due to age-related macular degeneration (AMD) using en face enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT). Methods:We enrolled 38 consecutive patients presenting to our hospitals with FV-PED due to AMD. Retinal images were automatically obtained with the Spectralis SD-HRA+OCT; the typical inverted 97 sections at 30µm intervals, each comprised of 9 averaged B-scans, were acquired in less than 60 seconds. The resultant images of en face cross-sections of the choroid (C-scans) were compared with indocyanine green angiography (ICGA) images, currently the only technique available ...

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    15. Spectral-Domain Optical Coherence Tomography as a Noninvasive Method to Assess Damaged and Regenerating Adult Zebrafish Retinas

      Spectral-Domain Optical Coherence Tomography as a Noninvasive Method to Assess Damaged and Regenerating Adult Zebrafish Retinas

      Purpose. These experiments assessed the ability of spectral-domain optical coherence tomography (SD-OCT) to accurately represent the structural organization of the adult zebrafish retina and reveal the dynamic morphologic changes during either light-induced damage and regeneration of photoreceptors or ouabain-induced inner retinal damage. Methods. Retinas of control dark-adapted adult albino zebrafish were compared with retinas subjected to 24 hours of constant intense light and recovered for up to 8 weeks or ouabain-damaged retinas that recovered for up to 3 weeks. Images were captured and the measurements of retinal morphology were made by SD-OCT, and then compared with those obtained by histology ...

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      Mentions: Bioptigen
    16. Corneal Topographic Analysis by 3-Dimensional Anterior Segment Optical Coherence Tomography after Endothelial Keratoplasty

      Corneal Topographic Analysis by 3-Dimensional Anterior Segment Optical Coherence Tomography after Endothelial Keratoplasty

      Purpose: To investigate the characteristics of the corneal topography with three-dimensional (3-D) anterior segment optical coherence tomography (AS-OCT) following Descemet stripping automated endothelial keratoplasty (DSAEK). Methods: Thirty-four eyes of 33 patients following DSAEK were studied. In addition to conventional topographic maps, the elevation map of the intrastromal interface and pachymetric maps of the host and graft were obtained by corneal topographic analysis using 3-D AS-OCT. The coefficient of variation of the corneal power (CV-Pa, CV-Pp) and root mean squares of the corneal elevation (RMS-Ea, RMS-Ep) of the anterior and posterior corneal surfaces were determined. Based on the combination of the ...

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      Mentions: Osaka University
    17. The Effects of Peripapillary Atrophy on the Diagnostic Ability of Stratus and Cirrus OCT in the Analysis of Optic Nerve Head Parameters and the Disc Size

      The Effects of Peripapillary Atrophy on the Diagnostic Ability of Stratus and Cirrus OCT in the Analysis of Optic Nerve Head Parameters and the Disc Size

      Purpose: We compared the diagnostic ability of Stratus and Cirrus optical coherence tomography (OCT) in optic nerve head (ONH) analysis, and examined the effects of optic disc size and peripapillary atrophy (PPA) on their diagnostic capacity. Methods: Stratus and Cirrus OCT were performed in 28 control and 78 glaucomatous eyes. ONH parameters and diagnostic capacity calculated from the area under the receiver operating characteristics curve (AUC) were compared between the two modalities. Glaucomatous eyes were classified by optic disc size and the presence/absence of PPA, and their AUCs were compared. Results: Rim area (AUC, 0.936) and rim volume ...

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    18. Biometric evaluation of anterior chamber changes after physiologic pupil dilation using Pentacam and anterior segment optical coherence tomography

      Biometric evaluation of anterior chamber changes after physiologic pupil dilation using Pentacam and anterior segment optical coherence tomography

      Purpose: To evaluate changes in anterior chamber (AC) morphology and iris volume induced by physiological mydriasis in fellow eyes of acute angle-closure patients and age-, sex-, and central AC depth-matched primary angle-closure suspects (PACS). Methods: Twenty-one fellow eyes of acute angle-closure patients and 40 eyes of 40 age-, sex-, and central AC depth-matched PACS were imaged using a Pentacam and anterior segment optical coherence tomography (AS-OCT) under light conditions, and after 5 min of darkness using AS-OCT. Iris volume was estimated using AS-OCT and a customized image-processing software. Results: Central AC depth, corneal curvature, axial length, and lens thickness did ...

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    19. Monitoring Morphological Changes in the Retina of Rhodopsin-/- Mice with Spectral Domain Optical Coherence Tomography

      Monitoring Morphological Changes in the Retina of Rhodopsin-/- Mice with Spectral Domain Optical Coherence Tomography

      Purpose: The rhodopsin-/- C57Bl/6 (rho-/-) mouse is a very important model for understanding retinal degenerative diseases. We used spectral domain optical coherence tomography (SD-OCT) to monitor the dynamic morphological changes in retina of rho-/- mice. Methods: Rho-/- mice and wild type C57Bl/6 (B6) mice at the age of 3, 6, 9 and 12 weeks were investigated using SD-OCT to obtain cross-sectional images of retina. The outer nuclear layer thickness was measured. Histological sections were used to compare with the OCT data. Electroretinograms (ERG) were performed to evaluate the physiological change for establishing the relationship between retinal morphology and ...

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    20. Automated Quantification of Volumetric Optic Disc Swelling in Papilledema Using Spectral-Domain Optical Coherence Tomography

      Automated Quantification of Volumetric Optic Disc Swelling in Papilledema Using Spectral-Domain Optical Coherence Tomography

      Purpose: To develop an automated method for the quantification of volumetric optic disc swelling in papilledema subjects using spectral-domain optical coherence tomography (SD-OCT) and to determine the extent that such volumetric measurements correlate with Frisén scale grades (from fundus photographs) and 2-D peripapillary retinal-nerve-fiber-layer (RNFL) and total-retinal (TR) thickness measurements from SD-OCT. Methods: A custom image-analysis algorithm was developed to obtain peripapillary circular RNFL thickness, TR thickness, and TR volume measurements from SD-OCT volumes of subjects with papilledema. In addition, peripapillary RNFL thickness measures from the commercially available Zeiss SD-OCT machine were obtained. Expert Frisén scale grades were independently obtained ...

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    21. Spatial correlation between hyperpigmentary changes on color fundus photography and hyperreflective foci on SDOCT in intermediate AMD

      Spatial correlation between hyperpigmentary changes on color fundus photography and hyperreflective foci on SDOCT in intermediate AMD

      Purpose: Macular hyperpigmentation is associated with progression from intermediate to advanced age-related macular degeneration (AMD). The purpose of this study was to accurately correlate hyperpigmentary changes with spectral domain optical coherence tomography (SDOCT) hyperreflective foci in eyes with non-advanced AMD. Methods: A prospective cross-sectional analysis of 314 eyes (314 subjects) with intermediate AMD was performed in the multicenter AREDS2 Ancillary SDOCT Study to correlate hyperpigmentary changes on color fundus photographs (CFP) with abnormal morphology on SDOCT. Spatial coregistration was performed with an automated algorithm in 2 non-overlapping subsets of 20 study eyes with double-masked CFP and SDOCT grading by certified ...

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    22. Quantification of retinal neural loss in patients with neuromyelitis optica and multiple sclerosis with or without optic neuritis using optical coherence tomography

      Quantification of retinal neural loss in patients with neuromyelitis optica and multiple sclerosis with or without optic neuritis using optical coherence tomography

      Objective: To compare retinal nerve fiber layer (RNFL) and macular thickness measurements in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO) with or without history of optic neuritis and in controls using Fourier-domain (FD) optical coherence tomography (OCT). Methods: Patients with MS (n=60), NMO (n=33), longitudinal extensive transverse myelitis (LETM) (n=28) and healthy controls (n=41) were submitted to ophthalmic examination, including automated perimetry, and to FD-OCT RNFL and macular thickness measurements. Five groups of eyes were compared: MS with or without previous optic neuritis, NMO, LETM and controls. Correlation between OCT and visual field (VF ...

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    23. Morphologic Analysis in Pathologic Myopia Using High-Penetration Optical Coherence Tomography

      Morphologic Analysis in Pathologic Myopia Using High-Penetration Optical Coherence Tomography

      PURPOSE. To retrospectively evaluate the morphologic choroidal and scleral characteristics in eyes with pathologic myopia using high-penetration optical coherence tomography (HP-OCT). METHODS. The subfoveal choroidal and scleral thicknesses were measured using the prototype HP-OCT with a 1,060-nm light source. We also measured the scleral thickness 3 mm superior, inferior, nasal, and temporal to the fovea on the horizontal and vertical OCT sections. The axial length (AL) in all eyes was measured using optical biometry. RESULTS. Fifty-eight eyes of 35 patients (7 men, 28 women; mean age, 65.5 years) with an AL exceeding 26.5-mm were examined. The mean ...

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    24. Measurement of Optic Disc Size and Rim Area with Spectral-Domain OCT and Scanning Laser Ophthalmoscopy

      Measurement of Optic Disc Size and Rim Area with Spectral-Domain OCT and Scanning Laser Ophthalmoscopy

      Purpose: To compare optic disc and neuroretinal rim area measurements from spectral-domain optical coherence tomography (SD-OCT) to those from confocal scanning laser ophthalmoscopy. Methods: Seventy-one eyes from 43 normal subjects or suspected/definite glaucoma patients were prospectively enrolled. All subjects had biometry with the IOLMaster and disc/retinal nerve fiber layer (RNFL) imaging with Cirrus SD-OCT (Optic Disc Cube 200x200) and Heidelberg Retina Tomograph (HRT). Keratometry-corrected (K-corrected) HRT measurements and uncorrected Cirrus disc and rim areas and disc measurements corrected for eye magnification with Bennett's formula (AL-corrected) along with 30-degree sectoral rim areas, vertical cup-to-disc ratio (VCDR), and cup ...

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