Flight Engineer Alexander Gerst uses the Optical Coherence Tomography camera during an Ocular Health vision test in the Harmony node of the International Space Station. Commander Steve Swanson (left) assists Gerst. Image credit:
NASA. Larger image (1 MB): http://www.nasa.gov/sites/default/files/oh_vision_test.jpg
Purpose: To investigate exudative macular disease, multi-functional optical coherence tomography (MF-OCT) using a 1-μm probe band was developed. The clinical utility of MF-OCT was examined in a descriptive case series. Methods: Ten eyes of nine subjects with exudative macular disease, including one eye with age-related macular degeneration (AMD), one eye with idiopathic neovascular maculopathy, and eight eyes with polypoidal choroidal vasculopathy (PCV), were investigated. Areas of 6 × 6 mm 2 around the pathologic region were scanned with 512 × 1024 depth scans in 6.6 seconds. Structural OCT, Doppler optical coherence angiography (OCA) and cumulative phase retardation images were obtained ...
Purpose:To compare Subfoveal Choroidal Thickness (SFCT) before and after unenventful cataract surgery using Enhanced Depth Imaging Optical Coherence Tomography (EDI OCT). Methods:A prospective study was conducted on 115 eyes of 95 patients who had phacoemulsification. Measurements of SFCT were performed preoperatively and one day (D1), seven days (D7), one month (M1) and three months (M3) after surgery using the EDI OCT technique. Central Retinal Thickness (CRT) was measured before surgery and at M1 and M3. Results:The 95 patients had a mean age of 76±8.3 years. The mean SFCT at baseline was 224±75μm. It ...
Purpose: To measure corneal and limbal epithelial thickness (ET) in normal subjects and to evaluate its variation with age by using anterior segment optical coherence tomography (AS-OCT). Methods: 180 normal subjects (180 healthy eyes) were enrolled and divided into four groups according to age: A (0-20 years), B (21-40 years), C (41-60 years), D (>60 years). Cornea and limbus were imaged with OCT. Corneal ET (CET) was obtained automatically by the built-in analysis software of the OCT system. Limbal ET (LET) in four quadrants was manually measured from OCT images. Results: CET of central 2-mm diameter zone in groups A ...
Purpose: To compare the diagnostic performance of different segmentations of the nerve fiber layer (NFL) thickness measurements using an artificial neural network and to define the optimal number of sectors with best diagnostic ability for glaucoma diagnosis. Methods: A total of 117 glaucoma patients and 123 normal subjects were included in the study. NFL thickness measurements were performed using the Spectralis-OCT (Heidelberg Engineering) to obtain the NFL thickness average; measurements from 2 semicircles, 4 quadrants, and 6, 8, 12, 16, 24, 32, and 64 sectors; and 768 uniformly divided locations around the peripapillary NFL. An artificial neural network evaluation was ...
Purpose: The aim of this study was to examine the association between transient interface fluid (TIF) and textural interface opacity (TIO) after Descemet stripping automated endothelial keratoplasty (DSAEK) surgery using intraoperative optical coherence tomography (iOCT) in the PIONEER (Prospective Intraoperative and Perioperative Ophthalmic ImagiNg with Optical CoherEncE TomogRaphy) study. Methods: All consecutive eyes that underwent DSAEK between October 2011 and September 2013 from the PIONEER intraoperative and perioperative OCT study were included. iOCT images were captured after lenticule apposition with complete air fill and after air-fluid exchange. Postoperative day 1 OCT images were obtained. Outcome variables included the presence of ...
Spectral domain optical coherence tomography (SOCT) is an important tool for the diagnosis and management of glaucoma. In an effort to help automate the detection of progressive structural glaucomatous optic nerve damage, Carl Zeiss Meditec has developed Guided Progression Analysis (GPA) software in conjunction with the Cirrus SOCT (Carl Zeiss Meditec, Dublin, Calif., USA). Here, we report a case in which the GPA merged information from 2 different patients, and another case in which data from alternate eyes was compared, making the final analysis invalid.
Background/Aims: To establish a screening and treatment method for fovea-threatening diabetic macular edema (DME) using spectral-domain optical coherence tomography (SD-OCT). In order to maintain good visual acuity (VA), focal/grid laser treatment for screened fovea-threatening DME was evaluated based on macular thickness map images produced by SD-OCT. Methods: In 66 diabetic eyes with no visual deterioration, the sensitivity and the specificity of SD-OCT without the use of mydriatics for the detection of fovea-threatening DME were determined. A definite diagnosis of DME was made under mydriasis, using slitlamp biomicroscopy with a contact lens. Eyes with fovea-threatening DME then underwent prophylactic ...
Background: The best technique to diagnose chloroquine/ hydroxychloroquine-induced retinopathy changes at the earliest remains ambiguous at present. In this study, we evaluated the time-domain optical coherence tomography (OCT) to identify retinal changes associated with chloroquine and hydroxychloroquine. Methods: One hundred patients with immunological diseases were included in the study. Fifty of them had been on chloroquine and/or hydroxychloroquine therapy for at least five years and the other 50 patients as controls. Detailed ophthalmic examination including Amsler grid , colour vision , automated threshold white perimetry using 10-2 protocol on Humphrey field analyzer, fluorescein angiography when indicated and time domain Optical Coherence ...
Purpose To investigate near-infrared reflectance (NIR) findings in central serous chorioretinopathy (CSCR) and to predict the choroidal vascular diffuse hyperpermeability (CVDHP) by NIR and enhanced depth imaging spectral-domain optical coherence tomography (EDI SD-OCT) noninvasively. Methods Retrospective analysis of 52 eyes of 50 CSCR patients with serous macular detachment. All patients received NIR, indocyanine green angiography (ICGA), and EDI SD-OCT. NIR pattern (irregular, defected, masked and enhanced), double layer sign (DLS) in EDI SD-OCT and CVDHP in ICGA were evaluated. In addition, we measured the length of photoreceptor outer segment (LPOS), and subfoveal choroidal thickness (SFCT) by Heidelberg eye explorer software ...
Purpose: To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Methods: Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 x 40[degrees] on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation ...
An image processing algorithm is developed for quantitative assessment of tear meniscus dynamics from continuous optical coherence tomography (OCT) measurements. Clinical utility of dynamic OCT tear meniscus measurement is assessed in studies of tear meniscus parameters. The results indicate that any apparent changes in the early post-blink phase meniscus parameters are essentially related to the longitudinal movements of the eye and not to the formation of tear meniscus corresponding to tear film build-up. Dynamic acquisition of tear film meniscus is essential for providing reliable estimates of its parameters such as height, depth, and area.
It has been very cumbersome to determine whether or not alignment is required before the fundus image is acquired after the tomographic image is acquired, causing the reduction in diagnostic efficiency. An ophthalmic apparatus is provided to solve this problem, which comprises an irradiation unit that irradiates an eye to be inspected with a first beam for acquiring a tomographic image of the eye and a second beam for acquiring a fundus image of the eye, the second beam having a beam diameter larger than the beam diameter of the first beam; and a determination unit that, based on information ...
The invention relates to an apparatus for generating a scannable optical delay for a beam of light and an apparatus for Fourier domain optical coherence tomography having said apparatus for generating a scannable optical delay in its reference arm (15). The light beam is directed to a pivotably driven mirror (10) from where it is reflected to a fixed mirror (12), and from there back retro reflected along the reference arm (5). Lens optics (9) are provided to ensure accurate optical alignment in several pivot positions of the pivotably driven mirror (10).
A method of analyzing an OCT image. An OCT image has many differently colored dots. The system detects the number of differently colored dots, quantifies them and performs statistical analysis to determine a likelihood of disease. The different colored dots correspond to different retina cell types and structures.
Diagnosis of corneal diseases is possible by measuring and evaluation of corneal thickness in different layers. Thus, the need for precise segmentation of corneal layer boundaries is inevitable. Obviously, manual segmentation is time-consuming and imprecise. In this paper, the Gaussian mixture model (GMM) is used for automatic segmentation of three clinically important corneal boundaries on optical coherence tomography (OCT) images. For this purpose, we apply the GMM method in two consequent steps. In the first step, the GMM is applied on the original image to localize the first and the last boundaries. In the next step, gradient response of a ...
Purpose To report a novel spectral-domain optical coherence tomography (SD-OCT) finding in children affected by tilted disc syndrome (TDS), and to correlate it with early visual field defects. Methods Patients between 5 and 17 years old with TDS were enrolled in this study. The diagnosis of TDS was made by stereoscopic fundus photography, when the upper edge of the optic disc protruded anteriorly relative to its lower edge. All eyes were examined with 12 radial SD-OCT B-scans of 12 mm centered on the optic disc; the fundus area encompassing the optic nerve was additionally scanned using several vertical and horizontal ...
To study and classify epiretinal membranes (ERMs) based on spectral domain optical coherence tomography (SD-OCT) findings. One hundred and twelve patients with ERMs were examined clinically and underwent OCT examination. The anatomical structure of the macula and vitreoretinal interface was studied. ERMs were classified in two categories: A, with posterior vitreous detachment (PVD) (91 cases), and B, with the absence of PVD (21 cases). Category A was divided into two subcategories: A1, without contraction of the ERM (37 cases), and A2, with the presence of membrane contraction (54 cases). A2 was further subdivided into A2.1, with retinal folding (15 ...
Purpose. Vitamin D insufficiency is associated with age-related macular degeneration. Our objective was to determine whether low serum 25-hydroxyvitamin D (25OHD) concentration was associated with macular thickness among older adults with no signs of macular dysfunction. Methods. Sixty-two French older community-dwellers with no patent macular dysfunction (mean±standard deviation, 71.2±5.0years; 45.2% female) included in the GAIT study (ClinicalTrials.gov number, NCT01315717) were separated into 2 groups according to serum 25OHD level (i.e., insufficient<50nmol/L or sufficient≥50nmol/L). The macular thickness was measured on 1000µm central macula with optical coherence tomography, and further ...
Purpose The aim of the study was to analyse macular changes after rhegmatogenous retinal detachment (RRD) repair using spectral-domain optical coherence tomography (SD-OCT). Methods Forty eyes with macula-on and 27 eyes with macula-off RRD underwent scleral buckling or vitrectomy and were postoperatively imaged using 2 SD-OCT devices (Cirrus® HD-OCT, RTVue-100®). Measurement of total and inner macular thickness consisting of ganglion cell layer + inner plexiform layer (GCL-IPL) using Cirrus or retinal nerve fibre layer + ganglion cell layer + inner plexiform layer (RNFL-GCL-IPL) using RTVue was performed. Results of inner macular thickness were compared with image results of 40 healthy controls. Qualitative analysis ...
Purpose: To assess the relationship between retinal structures measured by spectral-domain optical coherence tomography (OCT) and visual acuity in open-angle glaucoma (OAG) patients. Methods: In this cross-sectional observational study, 186 eyes from 186 OAG patients were included. The participants underwent RTVue OCT for measurement of circumpapillary retinal nerve fiber layer (cpRNFL) thickness and macular ganglion cell complex (mGCC) thickness. The correlations between best-corrected visual acuity (BCVA) and OCT parameters were evaluated using Pearson's partial correlation test and regression analysis. Receiver operating characteristic (ROC) curve analysis was performed to obtain a cutoff value for OCT parameters in detecting decreased visual ...
Purpose To analyze choroidal sublayers and vascular diameter in children, and to compare these choroidal features with those of adults. Design Retrospective observational study Methods This study included 96 eyes from 48 healthy children and 54 eyes from 27 healthy adults. The subfoveal choroidal thickness, large choroidal vessel layer thickness, medium choroidal vessel layer-choriocapillaris layer thickness, and large choroidal vessel diameter were estimated. The ratio of thickness of the large choroidal vessel layer to total choroidal thickness was calculated. The association between subfoveal choroidal thickness with large choroidal vessel layer, as well as ratio of thickness of the large choroidal ...
Purpose To compare intraocular lens implantation using a motorized injector vs standard manual injector through a 2.2-mm clear corneal incision. Methods Patients underwent standard phacoemulsification using a 2.2-mm clear corneal incision. Hydrophobic acrylic aspheric intraocular lens (Acrysof SN60WF intraocular lens (IOL)) was inserted using D cartridge with manual monarch injector or autosert motorized injector. IOL safety, final incision size and wound integrity in terms of anterior and posterior wound gape, and descemet’s membrane detachment were compared between the two groups at post-operative day 1 and at 1 month using Anterior Segment Optical Coherence Tomography. Results The study ...
Purpose: To evaluate the diagnostic accuracy of glaucoma in different stages, different types of glaucoma, and different ethnic groups using Stratus optical coherence tomography (OCT). Methods: We searched MEDLINE to identify available articles on diagnostic accuracy of glaucoma published between January 2004 and December 2011. A PubMed (National Center for Biotechnology Information) search using medical subject headings and keywords was executed using the following terms: "diagnostic accuracy" or "receiver operator characteristic" or "area under curve" or "AUC" and "Stratus OCT" and "glaucoma." The search was subsequently limited to publications in English. The area under a receiver operator characteristic (AUC) curve ...
