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 3D Curvelet-Based Segmentation and Quantification of Drusen in Optical Coherence Tomography Images

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
M. Esmaeili ◽  
A. M. Dehnavi ◽  
H. Rabbani
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging System ◽  
Imaging Modality ◽  
Age Related Macular Degeneration ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Treatment Protocols ◽  
Age Related ◽  
Sd Oct

Spectral-Domain Optical Coherence Tomography (SD-OCT) is a widely used interferometric diagnostic technique in ophthalmology that provides novel in vivo information of depth-resolved inner and outer retinal structures. This imaging modality can assist clinicians in monitoring the progression of Age-related Macular Degeneration (AMD) by providing high-resolution visualization of drusen. Quantitative tools for assessing drusen volume that are indicative of AMD progression may lead to appropriate metrics for selecting treatment protocols. To address this need, a fully automated algorithm was developed to segment drusen area and volume from SD-OCT images. The proposed algorithm consists of three parts: (1) preprocessing, which includes creating binary mask and removing possible highly reflective posterior hyaloid that is used in accurate detection of inner segment/outer segment (IS/OS) junction layer and Bruch’s membrane (BM) retinal layers; (2) coarse segmentation, in which 3D curvelet transform and graph theory are employed to get the possible candidate drusenoid regions; (3) fine segmentation, in which morphological operators are used to remove falsely extracted elongated structures and get the refined segmentation results. The proposed method was evaluated in 20 publically available volumetric scans acquired by using Bioptigen spectral-domain ophthalmic imaging system. The average true positive and false positive volume fractions (TPVF and FPVF) for the segmentation of drusenoid regions were found to be 89.15% ± 3.76 and 0.17% ± .18%, respectively.

scholarly journals In VivoComparison of 23- and 25-Gauge Sutureless Vitrectomy Incision Architecture Using Spectral Domain Optical Coherence Tomography

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Anderson Teixeira ◽  
Flavio A. Rezende ◽  
Camila Salaroli ◽  
Nonato Souza ◽  
Benedito Antonio Sousa ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Silicone Oil ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Open Wound ◽  
Longitudinal Length ◽  
Oil Residue ◽  
23 Gauge ◽  
Sd Oct

Purpose. To investigate thein vivoincision architecture using spectral domain optical coherence tomography (SD-OCT) in 23-gauge and 25-gauge transconjunctival suturelesspars planavitrectomy (TSPPV).Methods. A prospective observational study of 22 eyes of 22 patients that underwent three-port 25-gauge (10 eyes) or 23-gauge (12 eyes) TSPPV was performed. The three sclerotomies sites in each eye were analyzed by Corneal Adapter Model (CAM) RTVue SD-OCT (Optovue Inc., Fremont, CA, USA) with wound cross-section images (longitudinal and transversal) on days 1, 7, and 30 postoperatively. Transversal and longitudinal length, location, angle between the conjunctival surface tangent and the incision plane, and architecture deformations were evaluated.Results. All patients (22 eyes) completed the study and surgeries lasted less than 60 minutes. All wounds were obliquely performed, 23-gauge mean angle was 23 ± 5°, and 25-gauge angule was 21 ± 4°. Twenty-three-gauge sclerotomy transversal mean length was 1122 ± 242 μm and 25-gauge transversal sclerotomy mean length was 977 ± 174 μm; 23-gauge longitudinal mean length was 363 ± 42 μm and 25-gauge longitudinal sclerotomy mean length was 234 ±19 μm; 23-gauge open wound thickness mean was 61 ± 28 μm and 25-gauge open wound thickness mean was 22 ± 6 μm. All results were statistically significant (P<0.05). No vitreous incarceration or silicone oil residue was observed in incision sites with both gauges.Conclusions. The 23-gauge and 25-gauge architectural wound constructions were well visualized using CAM SD-OCT. Statistical differences between the two gauges were observed throughout the study period.

scholarly journals In Vivo 3D Imaging of Retinal Neovascularization Using Multimodal Photoacoustic Microscopy and Optical Coherence Tomography Imaging

2018 ◽  
Vol 4 (12) ◽  
pp. 150 ◽  
Author(s):  
Van Nguyen ◽  
Yanxiu Li ◽  
Michael Aaberg ◽  
Wei Zhang ◽  
Xueding Wang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Multimodal Imaging ◽  
Imaging System ◽  
Pathological Process ◽  
Retinal Neovascularization ◽  
Optical Coherence ◽  
Photoacoustic Microscopy ◽  
Ocular Imaging ◽  
Sd Oct

The pathological process of neovascularization of the retina plays a critical role in causing vision loss in several diseases, including diabetes, retinal vein occlusion, and sickle cell disease. Retinal neovascularization can lead to vitreous hemorrhage and retinal detachment, yet the pathological process of neovascularization is a complex phenomenon under active investigation. Understanding and monitoring retinal neovascularization is critically important in clinical ophthalmology. This study describes a novel multimodal ocular imaging system which combines photoacoustic microscopy (PAM) and a spectral domain optical coherence tomography (SD-OCT) to improve the visualization of retinal neovascularization (RNV), their depth, and the surrounding anatomy in living rabbits. RNV was induced in New Zealand rabbits by intravitreal injection of vascular endothelial growth factor (VEGF). The retinal vasculature before and after injection at various times was monitored and evaluated using multimodal imaging including color fundus photography, fluorescein angiography (FA), OCT, and PAM. In vivo experiments demonstrate that PAM imaging distinctly characterized the location as well as the morphology of individual RNV with high contrast at a safe laser energy of 80 nJ. SD-OCT was used to identify a cross-sectional structure of RNV. In addition, dynamic changes in the retinal morphology and retinal neovascularization were observed at day 4, 5, 6, 7, 9, 11, 14, 28, and day 35 after VEGF injection. PAM demonstrated high-resolution optical absorption of hemoglobin and vascular imaging of the retina and choroid with increased depth of penetration. With the current multimodal imaging system, RNV can be easily visualized in both 2D and 3D angiography. This multimodal ocular imaging system provides improved characterization of the microvasculature in a safe manner in larger rabbit eyes.

scholarly journals Morphology of Peripheral Vitreoretinal Interface Abnormalities Imaged with Spectral Domain Optical Coherence Tomography

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Rachel L. Chu ◽  
Nicole A. Pannullo ◽  
Christopher R. Adam ◽  
Mohammad R. Rafieetary ◽  
Eric J. Sigler
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Imaging Modality ◽  
Structural Features ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Vitreoretinal Interface ◽  
Retinal Breaks ◽  
Sd Oct

The objective of this study is to describe the clinical utility and morphologic characteristics of peripheral vitreoretinal interface abnormalities with spectral domain optical coherence tomography (SD-OCT). A prospective imaging analysis of 43 patients with peripheral vitreoretinal interface abnormalities seen on binocular indirect examination with scleral indentation was done. SD-OCT was evaluated for image quality and structural findings. Laser retinopexy was performed to surround all retinal breaks containing a full-thickness component via SD-OCT. Acceptable image quality for inclusion was obtained in 39/43 (91%) patients. Mean age was 41 ± 22 years, and mean follow-up was 14 ± 1.6 months. Decision to treat was altered following SD-OCT in 5% of the patients. Two cases of previously diagnosed operculated holes were found on SD-OCT to be partial-thickness operculated breaks or focal operculated schisis. Peripheral SD-OCT is a reliable and useful technique to examine the structural features of vitreoretinal interface abnormalities in vivo. This imaging modality is useful in the clinical management of suspected retinal breaks identified with indirect ophthalmoscopy.

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 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.

In vivo imaging with high-speed full-range complex spectral domain optical coherence tomography

2005 ◽  
Author(s):  
Erich Goetzinger ◽  
Michael Pircher ◽  
Rainer A. Leitgeb ◽  
Adolf F. Fercher ◽  
Christoph K. Hitzenberger
Keyword(s):  
Optical Coherence Tomography ◽  
In Vivo Imaging ◽  
High Speed ◽  
Full Range ◽  
Spectral Domain ◽  
Optical Coherence
Sign in / Sign up

Export Citation Format

Share Document