1. Articles from Byron L. Lam

    1-15 of 15
    1. Swept-Source Optical Coherence Tomography Detection of Bruch’s Membrane and Choriocapillaris Abnormalities in Sorsby Macular Dystrophy

      Swept-Source Optical Coherence Tomography Detection of Bruch’s Membrane and Choriocapillaris Abnormalities in Sorsby Macular Dystrophy

      Purpose: Swept-source optical coherence tomography angiography (SS-OCTA) was used to analyze Bruch's membrane (BM) and choriocapillaris (CC) abnormalities in undiagnosed family members with Sorsby macular dystrophy (SMD). Methods: In a family with SMD (TIMP3 Tyr191Cys), SS-OCTA imaging was performed using the 6X6mm scan patter and previously validated algorithms to detect abnormalities in BM and the CC, as well as the presence of reticular pseudodrusen (RPD) and macular neovascularization (MNV). Genetic analyses were performed for TIMP3 mutations. Results: Of eight family members, two were previously diagnosed with SMD and six were asymptomatic. SS-OCTA imaging of the 33-year-old proband revealed type ...

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    2. Optical Coherence Tomography Artifacts Are Associated With Adaptive Optics Scanning Light Ophthalmoscopy Success in Achromatopsia

      Optical Coherence Tomography Artifacts Are Associated With Adaptive Optics Scanning Light Ophthalmoscopy Success in Achromatopsia

      Purpose : To determine whether artifacts in optical coherence tomography (OCT) images are associated with the success or failure of adaptive optics scanning light ophthalmoscopy (AOSLO) imaging in subjects with achromatopsia (ACHM). Methods : Previously acquired OCT and non-confocal, split-detector AOSLO images from one eye of 66 subjects with genetically confirmed achromatopsia (15 CNGA3 and 51 CNGB3 ) were reviewed along with best-corrected visual acuity (BCVA) and axial length. OCT artifacts in interpolated vertical volumes from CIRRUS macular cubes were divided into four categories: (1) none or minimal, (2) clear and low frequency, (3) low amplitude and high frequency, and (4) high amplitude ...

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    3. Swept-Source Optical Coherence Tomography Angiography of an Amalric Choroidal Infarction in a Rare Presentation of Giant Cell Arteritis With Bilateral Corneal Edema

      Swept-Source Optical Coherence Tomography Angiography of an Amalric Choroidal Infarction in a Rare Presentation of Giant Cell Arteritis With Bilateral Corneal Edema

      A 73-year-old woman with 2 weeks of progressive painless vision loss was found to have bilateral corneal edema, jaw claudication, and temporal headache. Multimodal imaging revealed an Amalric choroidal infarct in the left eye visualized by widefield indocyanine green angiography and swept-source optical coherence tomography angiography (SS-OCTA). Prompt intravenous corticosteroid treatment resulted in 20/20 vision, and giant cell arteritis (GCA) was confirmed by a temporal artery biopsy. The case underscores the use of widefield SS-OCTA as a non-invasive test to aid in the diagnosis of GCA, as well as bilateral cornea edema as a rare presentation of GCA.

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    4. Quantitative retinal autofluorescence mapping with multimodal imaging technology

      Quantitative retinal autofluorescence mapping with multimodal imaging technology

      Imaging systems and methods of using the same are provided for monitoring the quantity of fluorescent pigment, for example lipofuscin, in the retinal pigment epithelium (RPE) layer of a retina in vivo. Various imaging modalities can be integrated into a single system and excited by a single broadband light source for the monitoring of the fluorescent pigment. The influence of varying optical properties found in the optical path of the pigment's auto-fluorescence between the RPE and an image receiver can be corrected.

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    5. Altered Macular Microvasculature in Mild Cognitive Impairment and Alzheimer Disease

      Altered Macular Microvasculature in Mild Cognitive Impairment and Alzheimer Disease

      Background: The goal of the present study was to analyze the macular microvacular network in mild cognitive impirment (MCI) and Alzheimer disease (AD). Methods: Twelve patients with AD and 19 patients with MCI were recruited together with 21 cognitively normal controls with a similar range of ages. Optical coherence tomography angiography was used to image the retinal microvascular network at the macular region, including retinal vascular network (RVN), superficial vascular plexus (SVP), and deep vascular plexus (DVP). Fractal analysis (box counting, D box ) representing the microvascular density was performed in different annular zones and quadrantal sectors. The macular ganglion cell ...

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    6. The measurement repeatability using different partition methods of intraretinal tomographic thickness maps in healthy human subjects

      The measurement repeatability using different partition methods of intraretinal tomographic thickness maps in healthy human subjects

      Purpose: To determine the repeatability and profiles with different partition methods in intraretinal thickness layers in healthy human subjects, using optical coherence tomography (OCT). Methods: A custom-built ultrahigh-resolution OCT was used to acquire three-dimensional volume of the macula in 20 healthy subjects. The dataset was acquired twice using the macular cube 512×128 protocol in an area of 6×6 mm 2 centered on the fovea. Commercially available segmentation software (Orion™) was used to segment the dataset into thickness maps of six intraretinal layers. The coefficient of repeatability and intraclass coefficient of correlation (ICC) were analyzed using hemispheric zoning and ...

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    7. Spectral-Domain Optical Coherence Tomography Documentation of Transsynaptic Retinal Degeneration

      Spectral-Domain Optical Coherence Tomography Documentation of Transsynaptic Retinal Degeneration

      Patients with post-geniculate neurologic disease and corresponding visual field loss may have ophthalmologic abnormalities detectable by spectral-domain optical coherence tomography (SD-OCT), presumably by transsynaptic retrograde retinal degeneration. Here, three such patients (ages 13 years through 75 years) illustrate thinning of the macula and ganglion cell complex corresponding to zones of visual field loss. Thinning of the retinal nerve fiber layer is not notable in these patients. SD-OCT may be a useful technique in diagnosing and following patients with post-geniculate neurologic disease.

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    8. Differentiating Mild Papilledema and Buried Optic Nerve Head Drusen Using Spectral Domain Optical Coherence Tomography

      Differentiating Mild Papilledema and Buried Optic Nerve Head Drusen Using Spectral Domain Optical Coherence Tomography

      Purpose To evaluate the clinical utility of spectral domain optical coherence tomography (SD-OCT) in differentiating mild papilledema from buried optic nerve head drusen (ONHD). Design Comparative case series. Participants Sixteen eyes of 9 patients with ultrasound-proven buried ONHD, 12 eyes of 6 patients with less than or equal to Frisén grade 2 papilledema owing to idiopathic intracranial hypertension. Two normal fellow eyes of patients with buried ONHD were included. Methods A raster scan of the optic nerve and analysis of the retinal nerve fiber layer (RNFL) thickness was performed on each eye using SD-OCT. Eight eyes underwent enhanced depth ...

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    9. Retinal oximetry using ultrahigh-resolution optical coherence tomography

      Retinal oximetry using ultrahigh-resolution optical coherence tomography

      Background: The purpose of this study was to investigate the repeatability of retinal oximetry using slit-lamp adapted ultrahigh-resolution optical coherence tomography (SL-UHR-OCT). Methods: SL-UHR-OCT was developed and fringe patterns were obtained for a major retinal artery and a major retinal vein. A-scans at the central wavelengths of 805 nm and 855 nm were analyzed for calculating optical density ratios (ODRs), from which the percentage oxygen saturation was calculated. Measurements were made on two occasions for each person. Repeatability and coefficients of repeatability were calculated. Results: The mean ODRs of the artery were 0.79 ± 0.86 and 0.88 ± 0 ...

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    10. Wide-Field Spectral-Domain Optical Coherence Tomography in Patients and Carriers of X-linked Retinoschisis

      Wide-Field Spectral-Domain Optical Coherence Tomography in Patients and Carriers of X-linked Retinoschisis

      Purpose: To evaluate macular and extramacular retinal anatomy in patients and carriers of X-linked retinoschisis (XLRS) using a wide-field spectral-domain optical coherence tomography (SD-OCT) imaging technique.Design: Case series.Participants: Six XLRS-affected male subjects and 3 XLRS female carriers.Methods: The subjects prospectively underwent XLRS DNA genotyping and comprehensive ophthalmic examination, including visual acuity, 30-2 Humphrey visual field, fundus photography, and wide-field SD-OCT, a montage technique to generate SD-OCT images spanning approximately 50 degrees horizontally and 35 degrees vertically of the posterior pole.Main Outcome Measures: Distribution and location of schisis cavities.Results: Among male subjects affected by XLRS, asymmetric ...

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    11. Quantitative analysis of the intraretinal layers and optic nerve head using ultra-high resolution optical coherence tomography

      Quantitative analysis of the intraretinal layers and optic nerve head using ultra-high resolution optical coherence tomography

      This study is designed to test the repeatability of the quantitative analysis of intraretinal layer thickness and cup-disc ratio of the optic nerve head using ultra-high resolution optical coherence tomography (UHR-OCT). Group A, containing 23 eyes of 12 healthy subjects, was imaged twice and group B, containing eight eyes of four subjects, was imaged three times. Intraretinal layers were segmented manually and the cup-to-disc ratio of the optic nerve head was analyzed. Custom-built automatic segmentation software was also used to segment a set of images for comparison. A total of nine intraretinal layers were visualized and extracted manually. With group ...

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    12. Automatic montage of SD-OCT data sets

      Automatic montage of SD-OCT data sets
      This paper proposes an automatic algorithm for the montage of OCT data sets, which produces a composite 3D OCT image over a large field of view out of several separate, partially overlapping OCT data sets. First the OCT fundus images (OFIs) are registered, using blood vessel ridges as the feature of interest and a two step iterative procedure to minimize the distance between all matching point pairs over the set of OFIs. Then the OCT data sets are merged to form a full 3D montage using cross-correlation. The algorithm was tested using an imaging protocol consisting of 8 OCT images ...
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    13. Ridge-based retinal image registration algorithm involving OCT fundus images

      Ridge-based retinal image registration algorithm involving OCT fundus images

      This paper proposes an algorithm for retinal image registration involving OCT fundus images (OFIs). The first application of the algorithm is to register OFIs with color fundus photographs; such registration between multimodal retinal images can help correlate features across imaging modalities, which is important for both clinical and research purposes. The second application is to perform the montage of several OFIs, which allows us to construct 3D OCT images over a large field of view out of separate OCT datasets. We use blood vessel ridges as registration features. The brute force search and an Iterative Closest Point (ICP) algorithm are ...

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    14. Characteristics of Optic Nerve Head Drusen on Optical Coherence Tomography Images

      BACKGROUND AND OBJECTIVE To describe the characteristics of optic nerve head drusen in optical coherence tomography (OCT) images. PATIENTS AND METHODS Cross-sectional images of the optic nerve were obtained in seven patients with optic nerve head drusen with Stratus and spectral-domain OCT (Carl Zeiss Meditec, Dublin, CA). These were compared to optic disc photographs, autofluorescence, and echography images. For comparison, these tests were performed on four patients with papilledema and three patients with small optic discs. RESULTS Optic nerve head drusen typically elevated the disc surface and appeared as an optically empty cavity, sometimes with a perceptible reflection from the ...
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    1-15 of 15
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    1. (12 articles) University of Miami
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    Ridge-based retinal image registration algorithm involving OCT fundus images Automatic montage of SD-OCT data sets Quantitative analysis of the intraretinal layers and optic nerve head using ultra-high resolution optical coherence tomography Wide-Field Spectral-Domain Optical Coherence Tomography in Patients and Carriers of X-linked Retinoschisis Retinal oximetry using ultrahigh-resolution optical coherence tomography Differentiating Mild Papilledema and Buried Optic Nerve Head Drusen Using Spectral Domain Optical Coherence Tomography Spectral-Domain Optical Coherence Tomography Documentation of Transsynaptic Retinal Degeneration The measurement repeatability using different partition methods of intraretinal tomographic thickness maps in healthy human subjects Intraoperative Use of Microscope-Integrated Optical Coherence Tomography for Subretinal Gene Therapy Delivery The truth about invisible posterior vitreous structures Increased Macrophage-like Cell Density in Retinal Vein Occlusion as Characterized by en Face Optical Coherence Tomography The Influence of Eyelid Position and Environmental Conditions on the Corneal Changes in Early Postmortem Interval: A Prospective, Multicentric OCT Study