Double Interferometer Design for Independent Wavefront Manipulation in Spectral Domain Optical Coherence Tomography

Abstract Spectral domain optical coherence tomography (SD-OCT) is a highly versatile method which allows for three dimensional optical imaging in scattering media. A number of recent publications demonstrated the technique to benefit from structured illumination and beam shaping approaches, e.g. to enhance the signal-to-noise ratio or the penetration depth with samples such as biological tissue. We present a compact and easy to implement design for independent wavefront manipulation and beam shaping at the reference and sample arm of the interferometric OCT device. The design requires a single spatial light modulator and can be integrated to existing free space SD-OCT systems by modifying the source arm only. We provide analytical and numerical discussion of the presented design as well as experimental data confirming the theoretical analysis. The system is highly versatile and lends itself for applications where independent phase or wavefront control is required. We demonstrate the system to be used for wavefront sensorless adaptive optics as well as for iterative optical wavefront shaping for OCT signal enhancement in strongly scattering media.

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Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator

Vision Research ◽

10.1016/j.visres.2005.08.028 ◽

2005 ◽

Vol 45 (28) ◽

pp. 3432-3444 ◽

Cited By ~ 77

Author(s):

Enrique J. Fernández ◽

Boris Považay ◽

Boris Hermann ◽

Angelika Unterhuber ◽

Harald Sattmann ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Liquid Crystal ◽

Adaptive Optics ◽

Spatial Light Modulator ◽

Three Dimensional ◽

Optical Coherence ◽

Light Modulator ◽

Ultrahigh Resolution

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In Vivo Three-Dimensional Characterization of the Healthy Human Lamina Cribrosa With Adaptive Optics Spectral-Domain Optical Coherence Tomography

Investigative Opthalmology & Visual Science ◽

10.1167/iovs.14-15177 ◽

2014 ◽

Vol 55 (10) ◽

pp. 6459 ◽

Cited By ~ 31

Author(s):

Zach Nadler ◽

Bo Wang ◽

Joel S. Schuman ◽

R. Daniel Ferguson ◽

Ankit Patel ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Adaptive Optics ◽

Three Dimensional ◽

Lamina Cribrosa ◽

Spectral Domain ◽

Optical Coherence ◽

Healthy Human

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

Scientific Reports ◽

10.1038/s41598-021-91999-2 ◽

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.

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

International Journal of Optics ◽

10.1155/2018/3726207 ◽

2018 ◽

Vol 2018 ◽

pp. 1-22 ◽

Cited By ~ 4

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.

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External limiting membrane: retinal structural barrier in diabetic macular edema

International Journal of Retina and Vitreous ◽

10.1186/s40942-021-00284-x ◽

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.

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

Klinische Monatsblätter für Augenheilkunde ◽

10.1055/a-1535-1685 ◽

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.

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Spectral-Domain Optical Coherence Tomography-Based Morphofunctional Characterization of Dome-Shaped Maculopathy in Indian Population

Journal of Ophthalmology ◽

10.1155/2020/8869455 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

Naresh Babu Kannan ◽

Sagnik Sen ◽

Prithviraj Udaya ◽

Obuli Ramachandran ◽

Kim Ramasamy

Keyword(s):

Optical Coherence Tomography ◽

Indian Population ◽

Subretinal Fluid ◽

Cross Sectional Study ◽

Spectral Domain ◽

Dome Height ◽

Optical Coherence ◽

Cross Sectional ◽

Sd Oct

Purpose. To study the clinicodemographic profile of dome-shaped maculopathy (DSM) eyes in the Indian population and characterization using spectral-domain optical coherence tomography (SD-OCT). Methods. This observational cross-sectional study included 25 eyes of 14 patients diagnosed with DSM. All eyes underwent SD-OCT for characterization of the dome profile and also to measure central macular thickness (CMT), subfoveal choroidal thickness (SFCT), and dome height (DH) and to detect the presence of subretinal fluid (SRF). Results. The mean age of patients was 48.36 ± 14.23 years (range, 28–65 years). Eleven patients had bilateral involvement. Mean axial length of all eyes was 24.25 ± 1.95 mm and mean spherical equivalent −4.23 ± 3.79 DS. Overall, 11/25 eyes (44%) had round domes, 9/25 eyes (36%) had horizontal domes, and 5/25 eyes (20%) had vertical domes, with a mean dome height at fovea of 500.54 ± 291.58 µm. Vertical domes had higher DH compared to horizontal or combined domes p = 0.02 . Six eyes (6/25, 24%) showed the presence of SRF; 60% of vertical domes had SRF, and 22.2% of horizontal domes had SRF. The eyes having SRF had significantly higher CMT p = 0.017 and DH p = 0.001 , especially in horizontal domes p = 0.023 . The eyes with thicker SFCT tended to have higher DH and poorer visual acuity. Conclusion. Indian DSM eyes may have relatively lesser amounts of myopia. Choroidal thickening may play a role in development of DSM and may also be related to development of subretinal fluid in such eyes.

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