1. Articles in category: Ophthalmology

    11185-11208 of 11963 « 1 2 ... 464 465 466 467 468 469 470 ... 497 498 499 »
    1. Corneal, Limbal, and Conjunctival Epithelial Thickness from Optical Coherence Tomography.

      Purpose. To compare human central corneal, limbal and bulbar conjunctival epithelial thickness in vivo using an Optical Coherence Tomographer (OCT). Methods. Thirteen healthy human subjects participated in this study. An OCT (Carl Zeiss, Meditec, Dublin, CA) was used to image central cornea, temporal corneo-scleral limbus and bulbar conjunctiva of the left eye. Two images were taken at each location. Thirty central measurements were averaged from each image for quantifying epithelial thickness. Results. In addition to the central cornea and limbal region, a band corresponding to bulbar conjunctival "epithelium" is apparent in OCT images, with respective thicknesses of 54.7 +/- 1 ...
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    2. Optopol picks new Americas distributor

      Optopol Technology, the listed manufacturer of ophthalmology diagnostic equipment, has selected a new distributor to market its devices in the US, Canada and South America. The name of the new partner and the details of the deal are due to be unveiled within days. The news comes one month after Optopol terminated a distribution agreement with Reichert, a leading US maker of ophthalmic instruments.
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    3. Optopol picks new Americas distributor

      Optopol Technology, the listed manufacturer of ophthalmology diagnostic equipment, has selected a new distributor to market its devices in the US, Canada and South America. The name of the new partner and the details of the deal are due to be unveiled within days. The news comes one month after Optopol terminated a distribution agreement with Reichert, a leading US maker of ophthalmic instruments.
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    4. Anterior segment optical coherence tomography in eye injuries

      Background To evaluate the usefulness of anterior segment optical coherence tomography (AS OCT) for initial diagnosis and for monitoring treatment results in eye injury cases. Methods We examined 38 eyes of 34 patients with different types of ocular injuries: penetrating injury (eight eyes), perforating injury (two eyes), intraocular foreign body (four eyes), ocular burn (nine eyes), contusion (13 eyes), and lamellar laceration (two eyes). The mean age of the patients was 33.8 years. AS OCT examination was performed at the initial visit, directly after injury, and repeated as treatment progressed. Both anterior chamber components and corneal pachymetry were evaluated ...
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    5. Evolution of lamellar macular hole studied by optical coherence tomography

      Abstract Purpose  To study the natural course of lamellar macular hole (LMH) as examined by optical coherence tomography (OCT) in a noncomparative observational case series. Methods  Forty-one eyes of 41 patients with LMH were included in this analysis. Baseline and final OCT findings related to LMH diameter, foveal thickness and visual acuity (VA) were collected and compared. Mean follow-up was 37.1 months. Main outcome measures were best-corrected visual acuity (BCVA), diameter of the LMH opening, foveal thickness, epiretinal membrane (ERM), posterior vitreous detachment (PVD) and vitreoretinal traction. Results  The diameter of the LMH increased by an average of 13 ...
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    6. The role of optical coherence tomography in the detection of pituitary adenoma

      Purpose: To analyse retinal nerve fibre layer (RNFL) thickness in eyes with compression of the optic chiasm by a pituitary adenoma. RNFL thickness was analysed with optical coherence tomography (OCT) and compared to visual field measurements using high-pass resolution perimetry (HRP).Methods: Sixteen eyes from eight patients with pituitary adenoma were studied. All had bitemporal visual field depression caused by compression of the optic chiasm. Patients were submitted to an ophthalmic examination more than 14 months after surgery (seven patients had undergone trans-sphenoidal and one trans-cranial adenomectomy). The examination included HRP, fundus photography and measurement of the peripapillar RNFL thickness ...
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    7. Comparison between confocal scanning laser tomography, scanning laser polarimetry and optical coherence tomography on the ability to detect localized retinal nerve fiber layer defects in glaucoma patients

      Background/Aim: To compare the ability of confocal scanning laser tomography (CSLT), scanning laser polarimetry (SLP) and optical coherence tomography (OCT) in recognizing localized retinal nerve fiber layer (RNFL) defects. Methods: 51 eyes from 43 patients with glaucoma were identified by two observers as having RNFL defects visible on optic disc photographs. 51 eyes of 32 normal subjects were used as controls. Three masked observers evaluated CSLT, SLP and OCT images to determine subjectively the presence of localized RNFL defects. Results: Interobserver agreement was highest with OCT, followed by SLP and CSLT (mean kappa: 0.83, 0.69 and 0 ...

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    8. Spectral/ Fourier domain Doppler Optical Coherence Tomography in the rodent retina (Thesis)

      Spectral/ Fourier domain Doppler Optical Coherence Tomography in the rodent retina (Thesis)
      Optical Coherence Tomography (OCT) is an emerging imaging technique based on low-coherence interferometry for noninvasive, high- resolution, cross-sectional imaging in a variety of biomedical fields. In ophthalmology, OCT has rapidly become a standard clinical diagnostic tool for retinal diseases, providing visualization of the retina with unprecedented detail. However, conventional time domain OCT systems are limited by low imaging speeds. Conventional time domain OCT systems use a mechanically scanned reference mirror to adjust the reference arm path length in time. Spectral / Fourier domain OCT systems use a spectrometer to detect the interference spectrum and do not require mechanical scanning of the ...
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    9. Discriminating Ability of the Cirrus High Definition (HD) Optical Coherence Tomography (OCT) for Glaucoma

      The Cirrus HD OCT is a newly developed imaging device of the spectral domain optical coherence tomography. Even though its resolution and speed are much better than the previous OCT, its reproducibility and diagnostic power for detecting the glaucomatous defect of retinal nerve fiber layer (RNFL) have not known yet. In the present study, we will retrospectively review the data of RNFL thickness measurement using the Cirrus HD OCT. After assessing the inter-test variability, the discriminating ability of the Cirrus HD OCT for glaucoma diagnosis will be determined by the ROC curves.
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    10. Modified OCT device provides higher-resolution images than current technology

      A modified version of a commercially available high-definition optical coherence tomography (OCT) device, adapted for imaging the anterior chamber angle, was able to provide higher-resolution images than current OCT devices and help investigators identify a new anatomic landmark. If this instrument is developed commercially, it could become a new gold standard for diagnosis of angle-closure glaucoma.
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    11. Morphologic Changes in Acute Central Serous Chorioretinopathy Evaluated by Fourier-Domain Optical Coherence Tomography

      Objective: To investigate morphologic alterations around fluorescein leakage sites using Fourier-domain optical coherence tomography (FD OCT) in acute central serous chorioretinopathy (CSC).Design: Observational case series.Participants: Twenty-one eyes with acute CSC with subjective symptoms for under 3 months.Methods: Patients underwent measurement of visual acuity, fundus observations, and FD OCT examinations at every visit with the intervals of 2 to 4 weeks until subretinal fluid (SRF) resolved. Fluorescein angiography was performed at baseline to confirm dye leakage sites. Horizontal and vertical OCT scans (B-scans and consecutive raster scans) of the fovea and fluorescein leakage sites were obtained.Main Outcome ...
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      Mentions: Osaka University
    12. Retinal Nerve Fiber Layer Thickness Measurement on Parapapillary Atrophy With the Cirrus High-Definition (HD) Optical Coherence Tomography (OCT)

      Retinal nerve fiber layer (RNFL) thickness measurement on the parapapillary atrophy is incorrect. Because a new spectral domain OCT, the Cirrus HD OCT, uses a movable circle to analyze the RNFL thickness, we may suggest a new analysis strategy for the parapapillary atrophy.
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    13. Effect of Blinking on Tear Volume After Instillation of Midviscosity Artificial Tears

      To determine by optical coherence tomography (OCT) the effect of blinking on ocular surface tear volume after instillation of artificial tears. Design Experimental study. Methods Normal human eyes (n = 21) were imaged to obtain dimensions of the tear film and menisci during blinking. The imaging was carried out immediately and five minutes after the instillation of 35 μl midviscosity artificial tears (1.0% carboxymethylcellulose; Refresh Liquigel; Allergan, Irvine, California, USA). The exposed ocular surface area and the lid lengths were used to calculate the volumes. Results Immediately after the instillation, total tear volume was increased (P .05). During the blink ...
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    14. In vivo analysis of wound architecture in 700 μm microphakonit cataract surgery

      Purpose: To analyze the clear corneal wound architecture in 700 μm cataract surgery (microphakonit) using anterior segment optical coherence tomography (AS-OCT).Setting: Dr Agarwal's Eye Hospital and Eye Research Centre, Chennai, India.Methods: Wound architecture was analyzed by AS-OCT 30 minutes after surgery and 1, 3, and 7 days postoperatively in 12 eyes (11 patients) that had microphakonit surgery. Five eyes had microphakonit with a 700 μm phaco tip with no intraocular lens (IOL) implantation, and 7 eyes had foldable IOL implantation after the main port was extended with a 2.8 mm keratome.Results: Twenty-four clear corneal wounds ...

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    15. Drusen Ultrastructure Imaging with Spectral Domain Optical Coherence Tomography in Age-related Macular Degeneration

      Subjects with drusen and a clinical diagnosis of AMD were enrolled in an SDOCT imaging study from August of 2005 to May of 2007. Foveal linear scans were acquired, and the image data were processed for analysis. Drusen were scored by 4 morphologic categories: shape, predominant internal reflectivity, homogeneity, and presence of overlying hyper-reflective foci. The prevalences of each morphologic pattern and combinations of morphologic patterns observed were calculated. The photographic appearance of each druse was compared with the tomographic classification. Interobserver and intraobserver agreement analysis was performed.
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    16. In vivo analysis of wound architecture in 700 um microphakonit cataract surgery.

      PURPOSE: To analyze the clear corneal wound architecture in 700 mum cataract surgery (microphakonit) using anterior segment optical coherence tomography (AS-OCT). SETTING: Dr Agarwal's Eye Hospital and Eye Research Centre, Chennai, India. METHODS: Wound architecture was analyzed by AS-OCT 30 minutes after surgery and 1, 3, and 7 days postoperatively in 12 eyes (11 patients) that had microphakonit surgery. Five eyes had microphakonit with a 700 mum phaco tip with no intraocular lens (IOL) implantation, and 7 eyes had foldable IOL implantation after the main port was extended with a 2.8 mm keratome. RESULTS: Twenty-four clear corneal wounds ...

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    17. Use of fundus perimetry (microperimetry) to quantify macular sensitivity.

      The advances in retinal imaging technologies have led to enormous innovation towards diagnostic in current ophthalmology, enabling the practitioner to detect early retinal changes and to document treatment effects. While, in the past, retinoscopy, visual acuity testing and perimetry played the major role in functional diagnostics, today, laser-based systems like laser scanning imaging systems especially for fluorescein-angiography, optical coherence tomography, electrodiagnostic systems and the analysis of retinal vessels may be used as well. However, the challenge to correlate subjective alterations or clinical changes with visual function, still remains. Micro- or fundus perimetry offers the option to test retinal sensitivity while ...
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    18. Retinal Angiography and Optical Coherence Tomography (Book)

      Retinal Angiography and Optical Coherence Tomography (Book)
      This new technology is expanding in daily practice. These expert authors are the ideal resource for clinicians seeking practical "how-to" information. Written for: Retina and glaucoma specialists and fellows, general ophthalmologists and residents in training. OCT is a relatively new imaging technique that is becoming increasingly popular among ophthalmologists in both private and academic settings. Imaging has been a slow moving area in ophthalmology for some time, but now OCT is providing another, more detailed source of demonstrable change in the eye, in diagnostic, therapeutic or post-surgical setting. (OCT and ultrasound both measure advancing disease states and post surgical healing ...
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    19. Ophthalmologic Apparatus For Imaging An Eye By Optical Coherence Tomography (Wo 2008/101359)

      Ophthalmologic Apparatus For Imaging An Eye By Optical Coherence Tomography (Wo 2008/101359)
      An OCT appliance (6) (optical coherence tomography appliance) comprises an OCT module (40) and a camera (32) for observing the fundus of an eye (7, 8). By recognizing characteristic features (biometric features) (3), the means defining the region observed by the OCT module (40), in particular the scanner (42) of the OCT module (40), is adjusted so that a predefined region of interest (2) is imaged by the OCT module. In a preferred embodiments, the apparatus is apt to be operated by a patient himself, and the data are transferred to a clinical server (7) so that a more frequent ...
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    20. Retinal Blood Flow and Nerve Fiber Layer Measurements in Early-Stage Open-Angle Glaucoma

      Purpose: To evaluate the relationship between retinal circulatory abnormalities and retinal nerve fiber layer (RNFL) thinning in early-stage open-angle glaucoma (OAG) to help elucidate the mechanisms underlying the development of glaucomatous optic neuropathy. Design: Prospective cross-sectional.Methods: Twelve patients with early OAG and a known maximum untreated intraocular pressure less than 22 mm Hg (age, 61.4 ± 9.7 years; Humphrey visual field mean deviation −2.7 ± 2.1) and eight age-matched healthy control subjects (age, 58.5 ± 8.3 years) were included in the study. Blood column diameter, centerline blood speed, and retinal blood flow were measured in the ...
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    21. Clues as to the Pathophysiology of Retinal Hemorrhages in Shaken Baby Syndrome Determined with Optical Coherence Tomography

      Guthkelch in 1971 reported on 22 patients younger than 18 months of age with various combinations of subdural hemorrhage, fractures, parenchymal brain injury, and retinal hemorrhages. He was the first to recognize the important role of repeated acceleration-deceleration forces—that is, shaking—as a form of abusive injury. In 1972 and 1974, Caffey expanded on this topic and coined the term Whiplash-Shaken Infant syndrome. Both authors recognized the frequent absence of external signs of trauma and the role of torn bridging vessels in the brain as the cause of the intracranial hemorrhage. Using autopsy evidence and a rudimentary dummy model ...
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    22. Imaging pulsatile retinal blood flow in human eye

      Bin Rao, Lingfeng Yu, Huihua Kenny Chiang et al. A functional Fourier domain optical coherence tomography instrument offering spectral Doppler imaging of in vivo pulsatile human retinal blood flow was constructed. An improved phase-resolved algorithm was developed to correct bulk motion artifacts. Spectral Doppler imaging provides complementary te ... [J. Biomed. Opt. 13, 040505 (2008)] published Mon Aug 25, 2008.
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    23. Relationship of the optical coherence tomography signal to underlying retinal histology in the tree shrew (Tupaia belangeri)

      PURPOSE. To interpret the retinal origin of the optical coherence tomography (OCT) signal by objectively (i.e. minimal investigator bias) aligning in vivo OCT longitudinal reflectivity profiles (LRPs) with corresponding vertical histological sections. METHODS. The Zeiss StratusOCT system was used to obtain retinal B-scans in vivo in eyes from adult tree shrews. Subsequently, the retinas were fixed and embedded. Semi-thin vertical sections through the retina were obtained from the same locations as the LRPs. A statistical correlation procedure that accounted for axial tissue shrinkage determined the best relationship between features in the LRP and sublaminae boundaries in corresponding histology sections ...
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    11185-11208 of 11963 « 1 2 ... 464 465 466 467 468 469 470 ... 497 498 499 »
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