1. Articles from Healio.com

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    1. Anterior segment OCT imaging after femtosecond laser cataract surgery

      Anterior segment OCT imaging after femtosecond laser cataract surgery

      PURPOSE: To report the anterior segment imaging characteristics after femtosecond laser assisted cataract surgery. METHODS: Cataract surgery was performed with the LenSx femtosecond laser (Alcon-LenSx Inc., Aliso Viejo, CA) in 40 eyes of 40 patients. The laser was programmed to perform a 4.5-mm capsulorhexis, a cross-pattern fragmentation of the nucleus, a 2.8-mm main incision, and a 1.0-mm side-port incision. The anterior segment was then analyzed using the Visante OCT anterior segment program (Zeiss-Meditec AG, Jena, Germany). RESULTS: The preoperatively set treatment parameters correlated well with the achieved results. For the capsulorhexis, the femtosecond laser cut was programmed ...

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    2. Comparison of Geographic Atrophy Measurements from the OCT Fundus Image and the Sub-RPE Slab Image

      Comparison of Geographic Atrophy Measurements from the OCT Fundus Image and the Sub-RPE Slab Image

      PURPOSE: To compare two different approaches to measuring areas of geographic atrophy (GA) using spectral-domain optical coherence tomography (SD-OCT). METHODS: Fifty eyes with GA were imaged with an SD-OCT instrument. OCT fundus images and sub– retinal pigment epithelium (RPE) slab images were generated. Three graders manually drew the GA boundaries on both en face images. An automated algorithm was used to segment the GA boundaries from the sub-RPE slabs. RESULTS: The agreement between the three manual measurements on both OCT fundus images (ICC = .998) and sub-RPE slabs (ICC = .999) was excellent. Area measurements from OCT fundus images and sub-RPE slabs ...

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    3. Assessment of Frame-Averaging Algorithms in OCT Image Analysis

      Assessment of Frame-Averaging Algorithms in OCT Image Analysis

      BACKGROUND AND OBJECTIVE: To evaluate frame registration and averaging algorithms for optical coherence tomography. PATIENTS AND METHODS: Twenty normal and 20 glaucomatous eyes were imaged. Objective differences were measured by comparing noise variance, spread of edge, and contrast-to-noise ratio. Subjective image quality was also evaluated. RESULTS: Two frame-averaging algorithms (FA400 and FA407) had better noise variance and contrast-to-noise ratio but worse spread of edge than did single frames ( P < .01). Both algorithms provided better subjective assessments of structure boundaries than did single images ( P < .001). FA407 had significantly lower spread of edge and better internal limiting membrane visualization than FA400 ...

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    4. SD-OCT Analysis of Regional Epithelial Thickness Profiles in Keratoconus, Postoperative Corneal Ectasia, and Normal Eyes

      SD-OCT Analysis of Regional Epithelial Thickness Profiles in Keratoconus, Postoperative Corneal Ectasia, and Normal Eyes

      PURPOSE: To assess corneal microarchitecture and regional epithelial thickness profile in eyes with keratoconus, postoperative corneal ectasia (ectasia), and normal unoperated eyes (controls) using spectral-domain optical coherence tomography (SD-OCT). METHODS: Regional corneal epithelial thickness profiles were measured with anterior segment SD-OCT (Optovue RTVue-100, Optovue Inc., Fremont, CA). Epithelial thickness was assessed at 21 points, 0.5 mm apart, across the central 6-mm of the corneal apex in the horizontal and vertical meridians. RESULTS: One hundred twenty eyes were evaluated, including 49 eyes from 29 patients with keratoconus, 32 eyes from 16 patients with ectasia, and 39 eyes from 21 control ...

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    5. Foveal duplication artifact with spectral-domain optical coherence tomography

      Foveal duplication artifact with spectral-domain optical coherence tomography

      The authors describe a rare artifact on two different spectral-domain optical coherence tomography (OCT) systems and explain its origin in patient- rather than hardware-related errors. During evaluation on spectral-domain OCT, four patients registered twin foveal depressions on the retinal thickness map display and were initially unable to fixate on the given target. Repeat scans on the same OCT system without changing scan protocol demonstrated no artifact after the patients began to fixate well, except in one patient who had nystagmus. Fundus and autofluorescence evaluation revealed no true duplication of fovea. Performing a repeat scan with greater focus on patient compliance ...

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    6. Identifying the boundaries of retinal pigment epithelial detachments using two spectral-domain optical coherence tomography instruments

      Identifying the boundaries of retinal pigment epithelial detachments using two spectral-domain optical coherence tomography instruments

      BACKGROUND AND OBJECTIVE: To compare two spectral-domain optical coherence tomography (SD-OCT) instruments in identifying the boundaries of retinal pigment epithelium detachment (PED). PATIENTS AND METHODS: 27 eyes were scanned with Cirrus and Spectralis SD-OCT instruments during a single visit. Two Cirrus scan patterns were used: the 512 × 128 and 200 × 200 covering a 6 × 6 mm (20° × 20°) area. The Spectralis scan pattern consisted of seven B-scans, averaged 51 times, covering a 30° × 5° area. The main outcome measures were the retinal thickness at the foveal center and the number of segmentation failures on the central B-scan. RESULTS: The Spectralis ...

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    7. Dynamic gonioscopy using optical coherence tomography

      Dynamic gonioscopy using optical coherence tomography

      BACKGROUND AND OBJECTIVE: To describe the use of anterior segment optical coherence tomography (AS-OCT) in studying the dynamic changes of the anterior chamber angle by corneal indentation. PATIENTS AND METHODS: In a prospective observational study, the anterior segments of 21 eyes were imaged using AS-OCT. After the initial scan, a second scan was executed on the same areas with a central corneal indentation. An evaluation of the reopening of the angle and its measurement were performed. RESULTS: With AS-OCT, the indirect signs were accurate enough to guide the diagnosis in all plateau iris confirmed by ultrabiomicroscopy. The angle widths were ...

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    8. Contrast Sensitivity and Color Vision in Eyes With Retinitis Pigmentosa and Good Visual Acuity: Correlations With SD-OCT Findings

      Contrast Sensitivity and Color Vision in Eyes With Retinitis Pigmentosa and Good Visual Acuity: Correlations With SD-OCT Findings

      BACKGROUND AND OBJECTIVE: To investigate the morphological substrate of the changes in visual function in eyes with retinitis pigmentosa and good visual acuity using spectral-domain optical coherence tomography (SD-OCT). PATIENTS AND METHODS: A total of 30 eyes of 17 patients with retinitis pigmentosa and visual acuity of 20/40 or better underwent contrast sensitivity and color vision testing. The retinal thickness at the fovea and macula and the length of the photoreceptor inner/outer segment (IS/OS) junction were assessed by SD-OCT. Structural-functional correlations were investigated. RESULTS: Contrast sensitivity correlated well with IS/OS length (Spearman r = 0.719, P ...

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    9. Further advances in optical coherence tomography 2012

      Further advances in optical coherence tomography 2012

      This fourth annual supplement to Ophthalmic Surgery, Lasers & Imaging devoted to optical coherence tomography (OCT) is a testament to the unique status and evolution of perhaps the single most important development of the era in ophthalmic imaging. Presented here are the latest reports of diagnosis and treatment challenges utilizing OCT to study and solve the problem and benefit the patient. They describe the most recent technological innovations and applications of the technique first described in 1991 in the journal Science , 1 and as a group represent the broad range of relevance of this imaging technique. Original clinical and experimental studies ...

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    10. Retinal and Choroidal Findings in Oxalate Retinopathy Using EDI-OCT

      Retinal and Choroidal Findings in Oxalate Retinopathy Using EDI-OCT

      A 55-year-old woman with extensive retinal crystalline deposition secondary to primary hyperoxaluria presented with bilateral loss of vision secondary to oxalate retinopathy. Enhanced depth imaging optical coherence tomography revealed intraretinal, subretinal, and intraretinal and subretinal pigment epithelium, and choroidal focal hyperreflective structures consistent with both neurosensory and uveal deposition of oxalate crystals. Serial optical coherence tomography revealed continued crystalline deposition with progressive retinal atrophy.

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    11. Choroidal Thickness Measurement in Highly Myopic Eyes Using SD-OCT

      Choroidal Thickness Measurement in Highly Myopic Eyes Using SD-OCT

      BACKGROUND AND OBJECTIVE: To measure macular choroidal thickness (CT) using spectral-domain optical coherence tomography (OCT) and to investigate the correlation between CT and age, degree of myopia, and history of macular choroidal neovascularization (CNV). PATIENTS AND METHODS: A cross-sectional study included 187 highly myopic eyes of 187 patients examined between January and December 2010. The choroid was imaged with spectral-domain OCT by changing the reference position from the vitreous to the choroid. CT was measured from the outer border of the hyperreflective line corresponding to the retinal pigment epithelium to the inner scleral border. RESULTS: The mean age was 47 ...

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    12. Intraoperative Use of AS-OCT During Intrastromal Corneal Ring Segment Implantation

      Intraoperative Use of AS-OCT During Intrastromal Corneal Ring Segment Implantation

      BACKGROUND AND OBJECTIVE: To evaluate femtosecond laser-created tunnels intraoperatively by anterior segment optical coherence tomography (AS-OCT) during intrastromal corneal ring segment implantation. PATIENTS AND METHODS: The study prospectively examined 13 eyes of 11 patients who underwent intrastromal corneal ring segment surgery with the aid of femtosecond laser. All eyes had keratoconus as the primary diagnosis. Eyes were examined by AS-OCT to image the tunnel immediately after femtosecond laser and before ring segment implantation. Tunnel depth was calculated automatically using the software's flap tool and calipers. RESULTS: The presence of air bubbles demonstrated the tunnel successfully by AS-OCT. Tunnel depth ...

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    13. High-Resolution OCT: An Innovative Tool for Posterior Segment Imaging

      High-Resolution OCT: An Innovative Tool for Posterior Segment Imaging

      Optimal management of posterior segment disorders requires a high-resolution and preferably noninvasive imaging tool for better definition of diseases. High-resolution optical coherence tomography can provide noninvasive, high-definition imaging of the posterior segment, allowing earlier diagnosis, better follow-up of chronic cases, and more accurate and timely monitoring of the effect of therapeutic agents. Recent findings suggest an individualized approach to vitreoretinal and choroidal diseases is possible based not only on traditional ophthalmic investigations, but also on high-resolution optical coherence tomography. This innovative tool has the combined advantages of high speed, high resolution, and safe use.

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    14. WaveLight FS200 vs Hansatome LASIK: Intraoperative Determination of Flap Characteristics and Predictability by Hand-held Bioptigen Spectral Domain Ophthalmic Imaging System

      WaveLight FS200 vs Hansatome LASIK: Intraoperative Determination of Flap Characteristics and Predictability by Hand-held Bioptigen Spectral Domain Ophthalmic Imaging System

      PURPOSE: To intraoperatively determine and compare the characteristics and predictability of LASIK flaps made by the WaveLight FS200 femtosecond laser (Alcon Laboratories Inc) and Hansatome (Bausch & Lomb) microkeratome using a hand-held spectral domain ophthalmic imaging system (Bioptigen Inc). METHODS: Sixty eyes from 30 patients undergoing bilateral LASIK were prospectively evaluated. Patients were divided into two equal groups to undergo flap creation with either 100-μm femtosecond laser flaps (FS flap group) or 120-μm microkeratome flaps (MK flap group). Flap thickness was measured intraoperatively after creation of the flap but prior to lifting using the hand-held probe of the spectral ...

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    15. In Vivo Imaging of Riboflavin Penetration During Collagen Cross-linking With Hand-held Spectral Domain Optical Coherence Tomography

      In Vivo Imaging of Riboflavin Penetration During Collagen Cross-linking With Hand-held Spectral Domain Optical Coherence Tomography

      PURPOSE: To compare the effect of complete versus grid-like epithelial removal on riboflavin penetration during collagen cross-linking (CXL) in vivo using hand-held spectral domain optical coherence tomography (OCT, Bioptigen Inc). METHODS: In this prospective, observational, comparative case series, patients with progressive keratoconus undergoing CXL with riboflavin and ultraviolet A (UVA) light were enrolled. Twenty eyes (20 patients) undergoing CXL using 0.1% riboflavin and UVA light (365 nm) were imaged intraoperatively at 30 and 60 minutes after starting the procedure, using hand-held spectral domain OCT. In 10 eyes, the epithelium was removed completely in the central 7-mm zone (complete removal ...

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      Mentions: Rohit Shetty Leica
    16. Evaluation of Retinal Nerve Fiber Layer Thickness in Patients With Anisometropic and Strabismic Amblyopia Using Optical Coherence Tomography

      Evaluation of Retinal Nerve Fiber Layer Thickness in Patients With Anisometropic and Strabismic Amblyopia Using Optical Coherence Tomography

      PURPOSE: To evaluate the retinal nerve fiber layer (RNFL) thickness of eyes with amblyopia using optical coherence tomography (OCT). METHODS: RNFL thickness measurements obtained by time-domain OCT of amblyopic eyes of patients with strabismus (35 patients) and patients with anisometropia (30 patients) were compared with their fellow eyes and age- and gender-matched healthy eyes (40 participants). RNFL thickness values of the groups were also compared and the correlation between RNFL thickness and refraction was evaluated. RESULTS: In the strabismic and anisometropic groups, there were no statistically significant differences in average RNFL thickness between amblyopic eyes and their fellow eyes ( P ...

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    17. Optical Coherence Tomography of Ocular Diseases, Third Edition (Book)

      Optical Coherence Tomography of Ocular Diseases, Third Edition (Book)

      For more than 17 years, Optical Coherence Tomography of Ocular Diseases has been the classic text on this essential imaging technology. This completely revised and updated Third Edition of Optical Coherence Tomography of Ocular Diseases reflects the quickly advancing technology of spectral domain optical coherence tomography (SD-OCT). Incorporated within over 600 pages are a multitude of updated features unique to this Third Edition including over 1,200 color images, state-of-the-art technology, and case presentations. These elements cohesively work together to successfully demonstrate the retina in normal and diseased states using SD-OCT. Optical Coherence Tomography of Ocular Diseases, Third Edition is ...

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    18. Characteristic SD-OCT Findings in Preeclampsia

      Characteristic SD-OCT Findings in Preeclampsia

      High-resolution spectral-domain optical coherence tomography of a patient affected by acute macular edema secondary to preeclampsia is described. The particular optical coherence tomography pattern was characterized by bilateral macular edema with a tent-shaped organization, associated with massive neurosensorial retinal detachment. Many hyperreflective irregular dots were evident in the context of a subfoveal clear cystic lesion. A different hyperreflective irregularity was detected in the retinal pigment epithelium. The central role of spectral-domain optical coherence tomography among instrumental imaging procedures and for final successful diagnosis in this particular macular edema is emphasized.

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    19. Comparison of Artemis 2 Ultrasound and Visante Optical Coherence Tomography Corneal Thickness Profiles

      Comparison of Artemis 2 Ultrasound and Visante Optical Coherence Tomography Corneal Thickness Profiles

      To compare corneal thickness profiles of cross-sections of cornea determined by arc-scanned immersion ultrasound and optical coherence tomography (OCT). METHODS: Corneas of 28 eyes from 14 participants were scanned in triplicate using the Artemis 2 high-frequency arc-scanned ultrasound system (ArcScan Inc) and the Visante OCT system (Carl Zeiss Meditec). Corneal thickness and reproducibility were compared within 3.5 mm of central cornea in the horizontal plane. RESULTS: Although highly correlated, Visante central and peripheral corneal thickness values were systematically thinner than Artemis 2 values. Within the central 0.5 mm, the difference was approximately 8 μm, but the difference increased ...

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    20. Intraoperative SD-OCT in Macular Surgery

      Intraoperative SD-OCT in Macular Surgery

      BACKGROUND AND OBJECTIVE: Intraoperative use of spectral-domain optical coherence tomography (SD-OCT) using an OCT-mounted surgical microscope could provide additional information to predict visual outcomes of macular surgery and identify intraoperative changes in the macular anatomy that affect visual recovery. PATIENTS AND METHODS: This interventional retrospective case study included 5 eyes of 5 consecutive patients with various macular pathologies. All patients underwent the standard surgery for idiopathic macular holes and epiretinal membranes (ERMs) using the same 25-gauge three-port pars plana technique. If present, the ERM was removed. The dye procedure was then repeated to stain and remove the internal limiting membrane ...

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    21. Rates of Abnormal Retinal Nerve Fiber Layer and Ganglion Cell Layer OCT Scans in Healthy Myopic Eyes: Cirrus Versus RTVue

      Rates of Abnormal Retinal Nerve Fiber Layer and Ganglion Cell Layer OCT Scans in Healthy Myopic Eyes: Cirrus Versus RTVue

      BACKGROUND AND OBJECTIVE: To compare rates of abnormal peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell layer scans acquired with Cirrus HD-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) and RTVue-100 (Optovue Inc., Fremont, CA) in healthy myopic eyes. PATIENTS AND METHODS: Forty-one non-glaucomatous myopic eyes (41 individuals) were scanned with Cirrus to measure RNFL and ganglion cell-inner plexiform layer (GCIPL) and with RTVue to measure peripapillary RNFL and ganglion cell complex (GCC) thicknesses. Rates of abnormal scans were calculated and compared between devices. Inter-device agreement in falsely classifying scans as abnormal was also assessed RESULTS: The rate of ...

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    22. Architectural Analysis of Clear Corneal Incision Techniques in Cataract Surgery Using Fourier-Domain OCT

      Architectural Analysis of Clear Corneal Incision Techniques in Cataract Surgery Using Fourier-Domain OCT

      BACKGROUND AND OBJECTIVE: To compare the architecture of single plane self-sealing clear corneal incision (SP-CCI) and shallow grooved self-sealing clear corneal incision (SG-CCI) after cataract surgery using Fourier-domain optical coherence tomography (FD-OCT). PATIENTS AND METHODS: An FD-OCT system with a corneal adaptor module was used to image the corneal incisions in radial sections in 44 eyes. A line scan pattern was used to measure the corneal incision, positioning the caliper mark perpendicular to the limbus. Measurements were performed immediately after cataract surgery and at postoperative days 1, 7, and 30. Incisions were analyzed regarding length, location, angle, architecture, and anatomic ...

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    23. Intrasession Reproducibility of RNFL Thickness Measurements Using SD-OCT in Eyes With Keratoconus

      Intrasession Reproducibility of RNFL Thickness Measurements Using SD-OCT in Eyes With Keratoconus

      BACKGROUND AND OBJECTIVE: To evaluate the intrasession reproducibility of the peripapillary retinal nerve fiber layer (RNFL) thickness measurements obtained by spectral-domain optical coherence tomography (SD-OCT) in eyes with keratoconus and normal eyes. PATIENTS AND METHODS: Peripapillary RNFL thickness measurements with SD-OCT were repeated three times during the same visit using the eye tracker and retest function in one eye of each participant. Reproducibility was evaluated using within-subject standard deviation (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC). RESULTS: For the overall global RNFL thickness, the values of the three parameters were Sw (± 1.96 standard error) 1.43 ...

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    24. Automated Detection of the Foveal Center Improves SD-OCT Measurements of Central Retinal Thickness

      Automated Detection of the Foveal Center Improves SD-OCT Measurements of Central Retinal Thickness

      BACKGROUND AND OBJECTIVE: To investigate the performance of an automated foveal center detection algorithm on spectral-domain optical coherence tomography (SD-OCT). PATIENTS AND METHODS: Fifty normal eyes and 50 eyes with early stage dry age-related macular degeneration (AMD) were analyzed. The actual scan center (SC), automatically detected foveal center (AF), and manually identified foveal center (MF) were compared. RESULTS: The mean of the radial distances was 89 ± 120 μm from MF to SC and 54 ± 41 μm from MF to AF for normal eyes and 179 ± 125 μm from SC to MF and 104 ± 62 μm from AF to MF for ...

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