1. Articles from iovs.org

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    1. The use of time-lapse optical coherence tomography to image the effects of microapplied toxins on the retina

      The use of time-lapse optical coherence tomography to image the effects of microapplied toxins on the retina

      Purpose: We developed a novel technique using a drug microperfusion device and time-lapse optical coherence tomography (OCT) for accelerated drug screening and retinotoxin characterization. Methods: Using an ex vivo rabbit eyecup preparation, we studied retinotoxin effects in real-time by microperfusing small retinal areas under a transparent fluoropolymer tube. Known retinotoxic agents were applied to the retina for 5 minute periods while changes in retinal structure, thickness, and reflectance were monitored with OCT. The OCT images of two agents with dissimilar mechanisms, cyanide and kainic acid, were compared with their structural changes seen histologically. Results: We found the actions of retinotoxic ...

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    2. Retinal Nerve Fiber Layer Defect Volume Deviation Analysis Using Spectral Domain Optical Coherence Tomography

      Retinal Nerve Fiber Layer Defect Volume Deviation Analysis Using Spectral Domain Optical Coherence Tomography

      Purpose: To report the retinal nerve fiber layer (RNFL) defect volume deviation according to structural RNFL loss in RNFL thickness maps Methods: RNFL defect is defined in RNFL thickness maps by the degree of RNFL loss. A 20% to 70% degree of RNFL loss was set with a 1% interval as the reference level for determining the boundary of RNFL defects. Each individual RNFL thickness map was compared to a normative database map and the region below the reference level was identified as an RNFL defect. The RNFL defect volume was calculated by summing the volumes of each pixel inside ...

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    3. Intereye Comparison of Cirrus OCT in Early Glaucoma Diagnosis and Detecting Photographic Retinal Nerve Fiber Layer Abnormalities

      Intereye Comparison of Cirrus OCT in Early Glaucoma Diagnosis and Detecting Photographic Retinal Nerve Fiber Layer Abnormalities

      Purpose: To compare the ability of various maps constructed using Cirrus optical coherence tomography (OCT), including the "intereye comparison" derived from the temporal-superior-inferior-nasal-temporal (TSNIT) map, in terms of glaucoma diagnosis and detection of RNFL defects identified in red-free fundus photographs. Methods: This cross-sectional study was conducted on a total of 131 open-angle glaucoma patients with early-stage visual field defects (mean deviation ≤ -6.0 dB) and 56 normal controls. Intereye differences were identified on TSNIT maps constructed by comparing the RNFL thickness curves of both eyes of individual patients and a separation of the RNFL thickness curves of either eye (by ...

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    4. Diagnostic ability of macular nerve fiber layer thickness using a new segmentation software in glaucoma suspects

      Diagnostic ability of macular nerve fiber layer thickness using a new segmentation software in glaucoma suspects

      Purpose. To assess the capacity of internal retinal layer thickness measurements made at the macula using new spectral domain OCT software (Spectralis OCT, Heidelberg Engineering) to distinguish between healthy subjects and those with suspected glaucoma. The diagnostic performance of such measurements was also compared with that of conventional peripapillary retinal nerve fiber layer (RNFL) thickness measurements. Methods. The study included 38 subjects with suspected glaucoma and 38 age-matched healthy subjects. In one randomly selected eye of each participant, thickness measurements at the level of the macula were made of the nerve fiber layer (mRNFL), the ganglion cell layer (GCL) and ...

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    5. Additive Diagnostic Role of Imaging in Glaucoma: Optical Coherence Tomography and Retinal Nerve Fiber Layer Photography

      Additive Diagnostic Role of Imaging in Glaucoma: Optical Coherence Tomography and Retinal Nerve Fiber Layer Photography

      Purpose: To investigate the additive diagnostic role of spectral-domain optical coherence tomography (SD-OCT) and red-free retinal nerve fiber layer photography (RNFLP) in making clinical glaucoma diagnosis. Methods: Four diagnostic combination sets, including the most recent image from each measurement of 196 glaucoma eyes (including the 44 preperimetric glaucoma eyes) and 101 healthy eyes, were prepared: (1) stereo disc photography and Humphrey visual field (SH); (2) SH and SD-OCT (SHO); (3) SH and RNFLP (SHR); 4) SHR and SD-OCT (SHRO). Each randomly sorted set was serially presented at one-month intervals to five glaucoma specialists who were asked to evaluate them in ...

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    6. Optical Coherence Tomography Study of Retinal Changes in Normal Aging and after Ischemia

      Optical Coherence Tomography Study of Retinal Changes in Normal Aging and after Ischemia

      Purpose. Age-related thinning of the retinal ganglion cell axons in the nerve fiber layer has been measured in humans using optical coherence tomography (OCT). In this study, we used OCT to measure inner retinal changes in 3-months-, one-year, and two-year-old mice and after experimental anterior ischemic optic neuropathy (AION). Methods. We used OCT to quantify retinal thickness in over 200 eyes at different ages before and after photochemical thrombosis model of AION. The scans were manually or automatically segmented. Results. In normal aging, there was 1.3 µm thinning of the ganglion cell complex (GCC) between 3-months and 1-year (P ...

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    7. Monitoring of strain-dependent responsiveness to TLR activation in the mouse anterior segment using SD-OCT

      Monitoring of strain-dependent responsiveness to TLR activation in the mouse anterior segment using SD-OCT

      Purpose: To determine whether spectral-domain optical coherence tomography (SD-OCT) can be used to longitudinally monitor inflammation in the mouse anterior segment and to identify any strain-dependent differences in responsiveness to distinct toll-like receptor ligands. Methods: Corneal inflammation was induced in BALB/c and C57BL/6 mice following central corneal abrasions and topical application of saline, toll-like receptor (TLR)-4 ligand, lipopolysaccharide (LPS) or TLR9 ligand, CpG-ODN (CpG). Anterior-segment images were captured using SD-OCT at baseline, 24 hours and one-week post-treatment. Corneal thickness, stromal haze and the number of keratic precipitates (KP) and anterior chamber (AC) cells were longitudinally compared to ...

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    8. Baseline OCT Measurements in the Idiopathic Intracranial Hypertension Treatment Trial: Part II. Correlations and Relationship to Clinical Features

      Baseline OCT Measurements in the Idiopathic Intracranial Hypertension Treatment Trial: Part II. Correlations and Relationship to Clinical Features

      Purpose: The accepted method to evaluate and monitor papilledema, Frisén grading, is an ordinal approach based on descriptive features. Part I showed spectral domain (SD) optical coherence tomography (OCT) in a clinical trial setting provides reliable measurement of the effects of papilledema on the optic nerve head (ONH) and peripapillary retina, particularly if a 3D-segmentation method is used for analysis.1 We evaluated how OCT parameters are interrelated and how they correlate with vision and other clinical features in idiopathic intracranial hypertension (IIH). Methods: 126 subjects in the IIH Treatment Trial (IIHTT) OCT substudy had Cirrus SD-OCT optic disc ...

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    9. Baseline OCT Measurements in the Idiopathic Intracranial Hypertension Treatment Trial: Part I. Quality Control,Comparisons and Variability

      Baseline OCT Measurements in the Idiopathic Intracranial Hypertension Treatment Trial: Part I. Quality Control,Comparisons and Variability

      Purpose: Optical coherence tomography (OCT) has been utilized to investigate papilledema in single site, mostly retrospective studies. We investigated whether spectral domain OCT (SD-OCT), which provides thickness and volume measurements of the optic nerve and retina, could reliably demonstrate structural changes due to papilledema in a prospective multi-site clinical trial setting. Methods: At entry, 126 subjects in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) with mild visual field loss had optic disc and macula scans using the Cirrus SD-OCT. Images were analyzed using the proprietary commercial and custom 3-D segmentation algorithms to calculate retinal nerve fiber layer (RNFL), total retinal ...

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    10. Optical coherence tomography and confocal microscopy following 3 different protocols of corneal collagen-crosslinking in keratoconus.

      Optical coherence tomography and confocal microscopy following 3 different protocols of corneal collagen-crosslinking in keratoconus.

      Purpose: To compare the efficacy and early morphological changes in the cornea following conventional (C-CXL), transepithelial by iontophoresis (I-CXL), and accelerated collagen cross-linking (A-CXL) in keratoconus. Methods: 45 eyes of 45 patients with progressive keratoconus who underwent corneal collagen crosslinking (CXL) were divided into 3 groups: C-CXL (n=15), A-CXL (n=15) and I-CXL (n=15). Patients were examined before surgery and at 1-month, 3-month, and 6-month intervals following surgery. Density of corneal sub-basal nerves, anterior and posterior keratocytes, corneal endothelium, demarcation line depth and maximal simulated keratometry values (Kmax) were all assessed. Results: Compared with preoperative values, the mean ...

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    11. Peripapillary rat sclera investigated in vivo with polarization sensitive optical coherence tomography

      Peripapillary rat sclera investigated in vivo with polarization sensitive optical coherence tomography

      Purpose: To demonstrate polarization sensitive (PS) optical coherence tomography (OCT) for non-invasive, volumetric, and quantitative imaging of the birefringent properties of the peripapillary rat sclera. To compare the findings in PS-OCT images to state-of-the-art histomorphometric analysis of the same tissues. Methods: A high-speed PS-OCT prototype operating at 840 nm was modified for imaging the rat eye. Densely sampled PS-OCT raster scans covering an area of ~1.5 mm × 1.5 mm centered at the papilla were acquired in the eyes of anesthetized, male Sprague Dawley rats. Cross-sectional PS-OCT images were computed and fundus maps displaying the birefringent properties of the ...

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    12. Influences of the inner retinal sublayers and analytical areas in macular scans by spectral domain OCT on the diagnostic ability of early glaucoma

      Influences of the inner retinal sublayers and analytical areas in macular scans by spectral domain OCT on the diagnostic ability of early glaucoma

      Purpose: To investigate the influences of the inner retinal sublayers and analytical areas in macular scans by spectral domain optical coherence tomography (OCT) on the diagnostic ability of early glaucoma. Methods: Sixty-four early (including 24 pre-perimetric) glaucomatous and 40 normal eyes underwent macular and peripapillary retinal nerve fiber layer (pRNFL) scans (3D-OCT-2000, Topcon). The area under the receiver operating characteristics (AUC) for glaucoma diagnosis was determined from the average thickness of the total 100 grids (6x6 mm), the central 44 grids (3.6x4.8 mm) and the peripheral 56 grids (outside of the 44 grids) and for each macular sublayer ...

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    13. Correlations Amongst Near-Infrared and Short-Wavelength Autofluorescence and Spectral Domain Optical Coherence Tomography in Recessive Stargardt Disease

      Correlations Amongst Near-Infrared and Short-Wavelength Autofluorescence and Spectral Domain Optical Coherence Tomography in Recessive Stargardt Disease

      Purpose: Short-wavelength (SW) fundus autofluorescence (AF) is considered to originate from lipofuscin in retinal pigment epithelium (RPE) and near-infrared (NIR) AF from melanin. In patients with recessive Stargardt disease (STGD1), we correlated SW-AF and NIR-AF with structural information obtained by spectral domain optical coherence tomography (SD-OCT). Methods: Twenty-four STGD1 patients (45 eyes; age 8 to 61 years) carrying confirmed disease-associated ABCA4 mutations were studied prospectively. SW-AF, NIR-AF and SD-OCT images were acquired. Results: Five phenotypes were identified according to features of the central lesion and extent of fundus change. Central zones of reduced NIR-AF were typically larger than areas of ...

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    14. Change in Drusen Area Over Time Compared Using Spectral Domain Optical Coherence Tomagraphy and Color Fundus Imaging

      Change in Drusen Area Over Time Compared Using Spectral Domain Optical Coherence Tomagraphy and Color Fundus Imaging

      Purpose: To investigate the relationship between drusen area measurements from color fundus images (CFIs) and spectral domain optical coherence tomography (SDOCT) datasets. Methods: Forty-two eyes from thirty Patients with drusen in the absence of geographic atrophy were recruited into a prospective study. Digital color fundus images and SDOCT images (CirrusTM HD-OCT) were obtained at baseline and at follow-up visits at 3 and 6 months. Registered, matched circles centered on the fovea with diameters of 3 mm and 5 mm were identified on both the CFIs and the SDOCT images. SDOCT drusen measurements were obtained using a commercially available proprietary algorithm ...

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    15. Variability and Repeatability of Quantitative, Fourier Domain-OCT Doppler Blood Flow in Young and Elderly Healthy Subjects

      Variability and Repeatability of Quantitative, Fourier Domain-OCT Doppler Blood Flow in Young and Elderly Healthy Subjects

      The purpose of this study was to determine the within-session variability and between-session repeatability of spectral Fourier-domain optical coherence tomography (Doppler FD-OCT) Doppler retinal blood flow measurements in young, and elderly subjects. Methods: Doppler FD-OCT blood flow was measured using the RTVue system (Optovue Inc., USA). One eye of each of 20 healthy young (24.7 ± 2.7 years) and 16 healthy elderly (64.6 ± 5.1 years) subjects was randomly selected and the pupil was dilated. The double circular scanning pattern of the RTVue was employed. Six Doppler FD-OCT measurements (i.e. each separate measurement comprising an upper, and ...

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    16. Anterior Segment Optical Coherence Tomography Parameters in Phacomorphic Angle Closure and Mature Cataracts

      Anterior Segment Optical Coherence Tomography Parameters in Phacomorphic Angle Closure and Mature Cataracts

      Purpose:To describe anterior segment optical coherence tomography (AS-OCT) parameters in phacomorphic angle closure (PMAC) eyes, mature cataract eyes and their fellow eyes, and identify those parameters that could be used to differentiate PMAC eyes from those with mature cataract and no PMAC. Methods:In this cross-sectional study a total of 33 PMAC subjects and 34 control patients with unilateral mature cataracts were enrolled. All patients underwent AS-OCT imaging and A-scan biometry of both eyes. Anterior chamber depth(ACD), anterior chamber area(ACA), iris thickness, iris curvature, lens vault(LV), and angle parameters including angle opening distance(AOD750) and trabecular ...

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    17. A comprehensive model for correcting RNFL readings of varying signal strengths in CIRRUS Optical Coherence Tomography (OCT)

      A comprehensive model for correcting RNFL readings of varying signal strengths in CIRRUS Optical Coherence Tomography (OCT)

      Purpose. Develop a model for the CIRRUSTM HD-OCT that allows for the comparison of retinal nerve fiber layer (RNFL) thickness measurements with dissimilar signal strengths (SS) and accounts for test-re-test variability. Methods. RNFLs were obtained in normals using the CIRRUSTM optic disc cube 200x200 protocol during a single encounter. Five RNFL scans were obtained with a SS of 9-10. Diffusion lens filters were used to degrade SS to obtain five scans at each SS group of 7-8, 5-6, and 3-4. The relationship between average RNFL thickness and SS was established and an equation was developed to allow for adjustment of ...

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    18. The cellular origins of the outer retinal bands in optical coherence tomography images

      The cellular origins of the outer retinal bands in optical coherence tomography images

      Purpose: To test the recently proposed hypothesis that the second OCT outer retinal band originates from the inner segment ellipsoid, by measuring: 1) thickness of this band within single cones, and 2) its respective distance from the external limiting membrane and outer segment tips. Methods: Adaptive optics OCT images were obtained from four normal subjects. Images were obtained at foveal (2∘) and perifoveal (5∘) locations. Cones (n = 9593) were identified and segmented in three dimensions using custom software. Features corresponding to bands 1, 2, and 3 were automatically identified. Thickness of band 2 was assessed in each cell by fitting ...

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    19. Macular measurements using spectral-domain optical coherence tomography in Chinese myopic children

      Macular measurements using spectral-domain optical coherence tomography in Chinese myopic children

      Purpose:To evaluate the macular thickness/volume in Chinese myopic children using spectral-domain optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA) and assess its correlation with spherical equivalent refraction (SE), axial length (AL), sex and age. Methods:A total of 194 eyes from 194 children (aged 6-17 years old) with emmetropia (-0.5D<SE≤0.5D), low myopia (-3.0D<SE≤-0.5D) and moderate to high myopia (SE≤-3.0D) were recruited in the study. Each child underwent standardized ophthalmic examinations including visual acuity (VA), cycloplegic refraction and AL measurement. The macular thickness for the nine ...

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    20. Quantitative SD-OCT Imaging Biomarkers as Indicators of Age-Related Macular Degeneration Progression

      Quantitative SD-OCT Imaging Biomarkers as Indicators of Age-Related Macular Degeneration Progression

      Purpose: We developed a statistical model based on quantitative characteristics of drusen to estimate the likelihood of conversion from early and intermediate age-related macular degeneration (AMD) to its advanced exudative form (AMD progression) in the short term (less than 5 years), a crucial task to enable early intervention and improve outcomes. Methods: Image features of drusen quantifying their number, morphology, and reflectivity properties, as well as the longitudinal evolution in these characteristics, were automatically extracted from 2146 spectral domain optical coherence tomography (SD-OCT) scans of 330 AMD eyes in 244 patients collected over a period of 5 years, with 36 ...

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    21. Influence of axial length on thickness measurements using spectral domain optical coherence tomography

      Influence of axial length on thickness measurements using spectral domain optical coherence tomography

      Purpose:To assess the influence of axial length on spectral domain optical coherence tomography (SD OCT) thickness measurements in patients with subretinal visual implant. Methods:Data from eight emmetropic pseudophakic eyes of eight patients with subretinal visual implant were analyzed retrospectively. These patients participated in the monocentric part of a multicentre trial (www.clinicaltrials.gov number: NCT01024803). The axial length was measured in three short (< 22.5 mm), three medium (22.51-25.50 mm) and two long (> 25.52 mm) eyes. Using Heidelberg Spectralis, the known thickness of subretinal implant microchip (70 µm) was measured on 15 images per eye ...

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    22. Outcomes of laser peripheral iridotomy in angle closure subgroups according to anterior segment optical coherence tomography parameters

      Outcomes of laser peripheral iridotomy in angle closure subgroups according to anterior segment optical coherence tomography parameters

      Purpose: To investigate the effect of laser peripheral iridotomy (LPI) in subgroups of angle closure eyes based on anterior segment optical coherence tomography (AS OCT)-derived parameters. Methods: Angle closure (primary angle closure (PAC) or PAC glaucoma (PACG)) eyes were imaged using ASOCT before and 2 weeks after LPI. A hierarchical cluster analysis was performed using AS OCT parameters obtained before LPI, such as anterior chamber depth (ACD), anterior chamber width (ACW), iris cross-sectional area (IA), Angle opening distance and iris thickness at 750 µm from the scleral spur (AOD750 , IT750), iris curvature (IC), lens vault (LV), and anterior chamber ...

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    23. Use of Anterior Segment Optical Coherence Tomography to Predict Corneal Graft Rejection in Small Animal Models

      Use of Anterior Segment Optical Coherence Tomography to Predict Corneal Graft Rejection in Small Animal Models

      Purpose: To correlate the degree of anterior chamber (AC) inflammation and corneal thickness evaluated by anterior segment optical coherence tomography (ASOCT) with corneal graft rejection status and to explore the value of ASOCT in assisting the diagnosis or prediction of graft rejection using a rat penetrating keratoplasty (PK) model. Methods: A total of 40 PKs were performed using Fisher rats (allogeneic groups) and Lewis rats (syngeneic group) as donors and Lewis rats as recipients: isograft control group (n=10), allograft untreated group (n=10), and allograft with 1% prednisolone acetate treatment group (n=20). All the grafts were evaluated for ...

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    24. High-Resolution Imaging of Photoreceptors in Macular Microholes [Retina]

      High-Resolution Imaging of Photoreceptors in Macular Microholes [Retina]

      Purpose. To assess photoreceptor structure in macular microholes by using adaptive optics scanning laser ophthalmoscopy (AO-SLO) and spectral-domain optical coherence tomography (SD-OCT) and compare with visual acuity. Methods. Fourteen eyes from 12 patients with macular microholes underwent a full ophthalmologic examination and imaging with a fundus camera, SD-OCT, and an original prototype AO-SLO system at each visit. Results. All eyes had a cone outer segment tip line disruption and a normal retinal pigment epithelium line on SD-OCT images. Adaptive optics scanning laser ophthalmoscopy revealed foveal cone disruption (13 eyes, round or oval; 1 eye, T-shaped) in all eyes. Cone disruption ...

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