Spectral domain optical coherence tomography (SD-OCT) Imaging of the Vascular-Avascular junction in the nursery in infants with retinopathy of prematurity

2016 ◽  
Vol 20 (4) ◽  
pp. e15
Author(s):  
Sharon Freedman ◽  
Cynthia A. Toth ◽  
Xi Chen ◽  
Christian Viehland ◽  
Shwetha Mangalesh ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Retinopathy Of Prematurity ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Oct Imaging ◽  
Sd Oct

scholarly journals Virtual-OCT: A simulated optical coherence tomography instrument

2014 ◽  
Vol 07 (05) ◽  
pp. 1450030 ◽  
Author(s):  
Ning Liu ◽  
Cuixia Dai ◽  
Yuanhe Tang ◽  
Peng Xi
Keyword(s):  
Optical Coherence Tomography ◽  
Dynamic Range ◽  
Partial Coherence ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Algorithm Optimization ◽  
Virtual Instrumentation ◽  
Parameter Evaluation ◽  
Oct Imaging ◽  
Sd Oct

We report the virtual instrumentation of both time-domain (TD) and spectral-domain (SD) optical coherence tomography (OCT) systems. With a virtual partial coherence source from either a simulated or measured spectrum, the OCT signals of both A-scan and B-scan were demonstrated. The spectrometric detector's pixel number, dynamic range, noise, as well as spectral resolution can be simulated in the virtual spectral domain (SD-OCT). The virtual-OCT system provides an environment for parameter evaluation and algorithm optimization for experimental OCT instrumentation, and promotes the understanding of OCT imaging and signal post-processing processes.

scholarly journals Spectral Domain Optical Coherence Tomography Imaging Performance Improvement Based on Field Curvature Aberration-Corrected Spectrometer

2020 ◽  
Vol 10 (10) ◽  
pp. 3657
Author(s):  
Seung Seok Lee ◽  
Woosub Song ◽  
Eun Seo Choi
Keyword(s):  
Optical Coherence Tomography ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Modulation Transfer ◽  
Field Curvature ◽  
Spatial Frequencies ◽  
Oct Imaging ◽  
Imaging Depth ◽  
Imaging Performance ◽  
Sd Oct

We designed and fabricated a telecentric f-theta imaging lens (TFL) to improve the imaging performance of spectral domain optical coherence tomography (SD-OCT). By tailoring the field curvature aberration of the TFL, the flattened focal surface was well matched to the detector plane. Simulation results showed that the spot in the focal plane fitted well within a single pixel and the modulation transfer function at high spatial frequencies showed higher values compared with those of an achromatic doublet imaging lens, which are commonly used in SD-OCT spectrometers. The spectrometer using the TFL had an axial resolution of 7.8 μm, which was similar to the theoretical value of 6.2 μm. The spectrometer was constructed so that the achromatic doublet lens was replaced by the TFL. As a result, the SD-OCT imaging depth was improved by 13% (1.85 mm) on a 10 dB basis in the roll-off curve and showed better sensitivity at the same depth. The SD-OCT images of a multi-layered tape and a human palm proved that the TFL was able to achieve deeper imaging depth and better contrast. This feature was seen very clearly in the depth profile of the image. SD-OCT imaging performance can be improved simply by changing the spectrometer’s imaging lens. By optimizing the imaging lens, deeper SD-OCT imaging can be achieved with improved sensitivity.

scholarly journals Macular Findings Obtained by Spectral Domain Optical Coherence Tomography in Retinopathy of Prematurity

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Muhammet Kazim Erol ◽  
Ozdemir Ozdemir ◽  
Deniz Turgut Coban ◽  
Ahmet Burak Bilgin ◽  
Berna Dogan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Birth Weight ◽  
Premature Infants ◽  
Gestational Age ◽  
Retinopathy Of Prematurity ◽  
Inverse Correlation ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Foveal Thickness ◽  
Sd Oct

Purpose.To examine the macular findings obtained with spectral domain optical coherence tomography (SD OCT) in infants with retinopathy of prematurity (ROP).Materials and Methods.The macular SD OCT images of 190 premature infants were analyzed. Data regarding central foveal thickness (CFT), cystoid macular edema (CME), and cyst grading were compared. The relationships of CFT with gestational age and birth weight were investigated.Results.The results were obtained from 358 eyes of 179 infants (81 females and 98 males) of a mean gestational age of30.9±2.7weeks and a mean birth weight of1609±477 g. ROP was diagnosed in 126 eyes and CME in 139 eyes. A significantly greater percentage of eyes with ROP were found to have CME (54%) compared to eyes without ROP (31%;P=0.001). The incidence of CME was 46.3% for stage 1 ROP, 57.1% for stage 2, and 87.5% for stage 3. There was a weakly inverse correlation between CFT, gestational age, and birth weight (P=0.025,r=-0.227;P=0.002,r=-0.182, resp., Spearman correlation test).Conclusions.High-quality SD OCT images can be obtained from premature infants using the iVue system. Severity and frequency of CME in premature infants increase as stage of ROP increases.

scholarly journals Comparison of Physiologic versus Pharmacologic Mydriasis on Anterior Chamber Angle Measurements Using Spectral Domain Optical Coherence Tomography

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Anna I. Dastiridou ◽  
Xiaojing Pan ◽  
ZhouYuan Zhang ◽  
Kenneth M. Marion ◽  
Brian A. Francis ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Anterior Chamber Angle ◽  
Lighting Condition ◽  
Inferior Angle ◽  
Oct Imaging ◽  
Chamber Angle ◽  
Sd Oct

Purpose. To compare the effects of physiologic versus pharmacologic pupil dilation on anterior chamber angle (ACA) measurements obtained with spectral domain optical coherence tomography (SD-OCT).Methods. Forty eyes from 20 healthy, phakic individuals with open angles underwent anterior segment OCT imaging under 3 pupillary states: (1) pupil constricted under standard room lighting, (2) physiologic mydriasis in a darkened room, and (3) postpharmacologic mydriasis. Inferior angle Schwalbe’s line-angle opening distance (SL-AOD) and SL-trabecular-iris-space area (SL-TISA) were computed for each eye and pupillary condition by masked, certified Reading Center graders using customized grading software.Results. SL-AOD and SL-TISA under pupillary constriction to room light were0.87±0.31 mm and0.33±0.14 mm2, respectively; decreased to0.75±0.29 mmP<0.01and0.29±0.13 mm2  P<0.01, respectively, under physiologic mydriasis; and increased to0.90±0.38 mmP<0.01and0.34±0.17 mm2  P=0.06under pharmacologic mydriasis compared to baseline.Conclusions. Using SD-OCT imaging, pharmacologic mydriasis yielded the widest angle opening, whereas physiologic mydriasis yielded the most angle narrowing in normal individuals with open iridocorneal angles. Accounting for the state of the pupil and standardizing the lighting condition would appear to be of importance for future studies of the angle.

scholarly journals Spectral-domain optical coherence tomography for evaluating palisades of Vogt in ocular surface disorders with limbal involvement

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying-Yi Chen ◽  
Yi-Chen Sun ◽  
Chia-Ying Tsai ◽  
Hsiao-Sang Chu ◽  
Jo-Hsuan Wu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Ocular Surface ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Slit Lamp ◽  
Ocular Rosacea ◽  
Unilateral Disease ◽  
Healthy Eyes ◽  
Slit Lamp Biomicroscopy ◽  
Sd Oct

AbstractSpectral-domain optical coherence tomography (SD-OCT) has been used to observe the morphology of the palisades of Vogt (POV) with satisfactory resolutions. In this study, we used SD-OCT to examine the microstructure of the POV in ocular surface disorders with limbal involvement. We detect subclinical limbal pathologies based on five parameters, including (1) decreased epithelial thickness, (2) loss of the sharp stromal tip, (3) loss of the smooth epithelial-stromal interface, (4) dilated stromal vessels, and (5) decreased POV density. Eighteen eyes of 10 patients with advancing wavelike epitheliopathy (AWE) and 15 eyes of 9 patients with phlyctenular keratitis/ocular rosacea were recruited. SD-OCT could detect abnormal changes in the POV in 100% of the lesion sites. In presumed-healthy areas of the diseased eyes diagnosed by slit-lamp biomicroscopy, SD-OCT detected abnormal changes in the POV in 100% of the eyes in both groups. In patients with unilateral disease, abnormal changes in the POV were detected by SD-OCT in 50% and 100% of presumed-healthy eyes diagnosed by slit-lamp biomicroscopy in the AWE group and phlyctenular keratitis/ocular rosacea group, respectively. SD-OCT is powerful in detecting POV changes in ocular surface disorders and can provide useful information that cannot be provided by slit-lamp biomicroscopy.

scholarly journals Design and Implementation Guidelines for a Modular Spectral-Domain Optical Coherence Tomography Scanner

2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Farid Atry ◽  
Israel Jacob De La Rosa ◽  
Kevin R. Rarick ◽  
Ramin Pashaie
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging System ◽  
Optical Design ◽  
Spectral Domain ◽  
Design Parameters ◽  
Optical Coherence ◽  
Custom Made ◽  
Essential Knowledge ◽  
Sd Oct

In the past decades, spectral-domain optical coherence tomography (SD-OCT) has transformed into a widely popular imaging technology which is used in many research and clinical applications. Despite such fast growth in the field, the technology has not been readily accessible to many research laboratories either due to the cost or inflexibility of the commercially available systems or due to the lack of essential knowledge in the field of optics to develop custom-made scanners that suit specific applications. This paper aims to provide a detailed discussion on the design and development process of a typical SD-OCT scanner. The effects of multiple design parameters, for the main optical and optomechanical components, on the overall performance of the imaging system are analyzed and discussions are provided to serve as a guideline for the development of a custom SD-OCT system. While this article can be generalized for different applications, we will demonstrate the design of a SD-OCT system and representative results for in vivo brain imaging. We explain procedures to measure the axial and transversal resolutions and field of view of the system and to understand the discrepancies between the experimental and theoretical values. The specific aim of this piece is to facilitate the process of constructing custom-made SD-OCT scanners for research groups with minimum understanding of concepts in optical design and medical imaging.

scholarly journals External limiting membrane: retinal structural barrier in diabetic macular edema

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Sandeep Saxena ◽  
Levent Akduman ◽  
Carsten H. Meyer
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Edema ◽  
Diabetic Macular Edema ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Barrier Effect ◽  
External Limiting Membrane ◽  
Ellipsoid Zone ◽  
Structural Barrier ◽  
Sd Oct

AbstractAdvances in spectral-domain optical coherence tomography (SD-OCT) technology have enhanced the understanding of external limiting membrane (ELM) and ellipsoid zone (EZ) in diabetic macular edema. An increase in VEGF has been demonstrated to be associated with sequential ELM and EZ disruption on SD-OCT. An intact ELM is a prerequisite for an intact EZ in DME. Anti-VEGF therapy leads to restoration of barrier effect of ELM. The ELM restores first followed by EZ restoration.

Reliability of Corneal, Epithelial, and Stromal Thickness Mapping for a 9-mm Zone Using Spectral-Domain Optical Coherence Tomography

2021 ◽  
Author(s):  
Daniel Krause ◽  
Niklas Mohr ◽  
Mehdi Shajari ◽  
Wolfgang J. Mayer ◽  
Siegfried Priglinger ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Intraclass Correlation ◽  
Age Groups ◽  
Corneal Stroma ◽  
Correlation Coefficients ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Noninvasive Technique ◽  
Intraclass Correlation Coefficients ◽  
Sd Oct

Abstract Purpose To evaluate the reliability of spectral-domain optical coherence tomography (SD-OCT; RTVue XR; Optovue, Inc., Fremont, CA, USA) for thickness mapping of the entire cornea (CT), corneal epithelium (ET). and corneal stroma (ST) over a 9-mm zone in healthy eyes. We sought to develop reference values for different age groups and elucidate potential sex- and age-dependent characteristics of corneal sublayer pachymetry maps. Methods Three consecutive SD-OCT scans were obtained in 166 healthy right eyes (mean age = 50 ± 20 years). The thickness maps contain 25 sectors over a 9-mm diameter zone. To test measurement reliability, intraclass correlation coefficients (ICC), coefficients of variation (CoV), and within-subject standard deviations (WSSD) were calculated. Results CT, ET, and ST ICCs ranged from 0.961 to 0.998, 0.896 to 0.945, and 0.955 to 0.998, respectively. CoV values for CT, ET, and ST ranged between 0.3 and 1.5%, 1.6 and 4.2%, and 0.4 and 1.7%, respectively. WSSD ranged from 6 to 41, 4 to 8, and 7 to 46 µm, respectively. A negative correlation was found between age and ET (p < 0.05) but not between age and ST or CT. No gender-related differences in CT, ET, or ST were detected. CoV of CT, ET, and ST measurements showed a positive correlation with age in 28, 64, and 28% of the sectors, respectively. Conclusion SD-OCT is a rapid and noninvasive technique that provides excellent reliability for corneal sublayer thickness measurements over a 9-mm zone. The reliability of the ET measurement seems to be negatively affected by age. Peripheral CT and global ET thin with age.

Sign in / Sign up

Export Citation Format

Share Document