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 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 Morphological Predictive Features on Spectral-Domain Optical Coherence Tomography for Visual Outcomes in Neovascular Age-Related Macular Degeneration Treated with Ranibizumab

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Georges Azar ◽  
Benjamin Wolff ◽  
Flore De Bats ◽  
Jeremie Halfon ◽  
Mate Streho ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Degeneration ◽  
Morphological Features ◽  
Age Related Macular Degeneration ◽  
Spectral Domain ◽  
Prognostic Indicators ◽  
Optical Coherence ◽  
Multicentric Study ◽  
Age Related ◽  
Sd Oct

Purpose. To identify spectral-domain optical coherence tomography (SD-OCT) predictive morphological features for the outcome of Ranibizumab therapy for neovascular age-related macular degeneration (AMD). Methods. This is a retrospective multicentric study that involved 64 eyes with naïve AMD. Patients who received three monthly intravitreal injections of Ranibizumab were stratified into (1) “responders” [≥ 5 letters gain on Early Treatment Diabetic Retinopathy Study (ETDRS) scale] and (2) “nonresponders” (< 5 letters gain). Best-corrected visual acuity (BCVA) and SD-OCT morphological features were compared at baseline and one month after three consecutive injections of Ranibizumab. Univariate and multivariate analyses were carried out to correlate these morphological features with the change in BCVA. Results. Among the 64 patients enrolled, 40 (62.5%) were “responders” and 24 (37.5%) “nonresponders”. Age, sex, and BCVA were comparable between both groups. A multivariate correlational analysis found that subfoveal choroidal thickness (SFCT) and the presence of pigment epithelial detachment (PED) > 250 μm at baseline were two independent prognostic indicators of final BCVA. No other SD-OCT morphological studied features seem to affect final BCVA after Ranibizumab treatment. Conclusion. SFCT and the presence of PED > 250 μm are two significant biomarkers that may predict improvement after Ranibizumab therapy for AMD. These markers may guide ophthalmologists' treatment decision under financial constraints and limited time.

scholarly journals Low-Reflectivity Drusen With Overlying RPE Damage Revealed by Spectral-Domain OCT: Hint for the Development of Age-Related Macular Degeneration

2021 ◽  
Vol 8 ◽  
Author(s):  
Shasha Yang ◽  
Zongyin Gao ◽  
Haijiang Qiu ◽  
Chengguo Zuo ◽  
Lan Mi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Degeneration ◽  
Retinal Pigment ◽  
Morphological Characteristics ◽  
Age Related Macular Degeneration ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Age Related ◽  
Sd Oct

Purpose: To observe the relationship between the characteristic changes in the drusen morphology revealed by the spectral-domain optical coherence tomography (SD-OCT) and the progression of age-related macular degeneration (AMD).Methods: A total of 380 drusen in 45 eyes in 35 patients with the intermediate drusen were longitudinally followed up every 6 months by SD-OCT for a period of 24 months. The drusen were divided into the dynamic group and stable group according to the following parameters: number, volume, concurrent retinal pigment epithelium (RPE)/ellipsoid zone (EZ) damage, and the development of advanced AMD. The morphological characteristics of the progressive or stable drusen were further analyzed. Odds ratios (ORs) and the risk for the drusen progression were calculated.Results: The level of interobserver and intraobserver agreement for each drusen tomographic morphological parameters ranged from 82.7 to 90%. At the end of an average follow-up of 15.92 ± 6.99 months, six patients developed choroidal neovascularization and no patients developed geographic atrophy. Finally, 139 drusen changed and 241 drusen remained stable. The drusen with low reflectivity (p &lt; 0.001; OR: 5.26; 95% CI: 2.24–12.36), non-homogeneity without a core (p &lt; 0.001; OR: 4.31; 95% CI: 2.08–8.92), RPE damage (p &lt; 0.001; OR: 28.12; 95% CI: 9.43–83.85), and the EZ damage (p &lt; 0.001; OR: 14.01; 95% CI: 5.28–37.18) were significantly associated with active change; the drusen with low reflectivity (p = 0.01; OR: 2.95; 95% CI: 1.29–6.75) and decreased overlying RPE reflectivity (p &lt; 0.001; OR: 21.67; 95% CI: 9.20–51.02) were the independent predictors for progression. The drusen with high reflectivity were significantly associated with stabilization (p = 0.03; OR: 0.17; 95% CI: 0.04–0.84).Conclusion: Spectral-domain optical coherence tomography is an optimized, accurate, and efficient method to follow-up the drusen. The intermediate non-exudative AMD prognosis of the patient was most strongly correlated with the drusen reflectivity and disruption of the overlying RPE layer. The drusen with low reflectivity and overlying RPE damage were more likely to progress and required frequent follow-up.

Spectral-Domain Optical Coherence Tomography Associations of Neovascular Conversion in Age-Related Macular Degeneration

2018 ◽  
Vol 2 (2) ◽  
pp. 69-78
Author(s):  
Siqing Yu ◽  
Sebastian Wolf ◽  
Marion R. Munk ◽  
Martin S. Zinkernagel ◽  
Andreas Ebneter
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Degeneration ◽  
Pigment Epithelium ◽  
Age Related Macular Degeneration ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Time Points ◽  
Age Related ◽  
Fellow Eyes ◽  
Sd Oct

Purpose: To identify spectral-domain optical coherence tomography (SD-OCT) features associated with exudative conversion in fellow eyes of patients treated for neovascular age-related macular degeneration (nAMD) in their first eye. Methods: Retrospective observational study. Spectral-domain optical coherence tomography images of converting fellow eyes (study eyes) from 83 patients with nAMD were compared to fellow eyes of age- and sex-matched patients with nAMD who did not convert (control eyes). Parameters related to drusen, pigment epithelium detachment, hyperreflective foci (HRF), retinal pigment epithelium atrophy, small cystic cavities, and vitreoretinal interface were graded. Longitudinal analysis in study eyes and cross-sectional comparison with control eyes at the last 3 semiannual visits before nAMD conversion were performed. Results: For most biomarkers, the prevalence in study eyes increased and imaging findings worsened more than in control eyes. Drusen size and reticular pseudodrusen presence were significantly greater in converting eyes at all 3 time points. Outer retinal small cystic cavities were significantly more common in study eyes shortly before conversion. Binary logistic regression revealed that biggest drusen width was significantly associated with nAMD at all 3 time points (odds ratio [OR] > 1.010; P < .001). The presence of soft drusen was strongly associated with nAMD 18 months before conversion (OR: 7.034; P = .040). Clustering HRF in the inner retina were significantly associated with nAMD both 12 (OR: 1.324; P = .049) and 6 months (OR: 2.161; P = .035) before conversion. Conclusions: Emergence of HRF in fellow eyes, particularly in the inner retina, are sensitive SD-OCT features indicating conversion to exudative disease in patients treated unilaterally for nAMD.

scholarly journals Accuracy of a Machine-Learning Algorithm for Detecting and Classifying Choroidal Neovascularization on Spectral-Domain Optical Coherence Tomography

2021 ◽  
Vol 11 (6) ◽  
pp. 524
Author(s):  
Andreas Maunz ◽  
Fethallah Benmansour ◽  
Yvonna Li ◽  
Thomas Albrecht ◽  
Yan-Ping Zhang ◽  
...  
Keyword(s):  
Machine Learning ◽  
Optical Coherence Tomography ◽  
Choroidal Neovascularization ◽  
Learning Algorithm ◽  
High Accuracy ◽  
Age Related Macular Degeneration ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Age Related ◽  
Sd Oct

Background: To evaluate the performance of a machine-learning (ML) algorithm to detect and classify choroidal neovascularization (CNV), secondary to age-related macular degeneration (AMD) on spectral-domain optical coherence tomography (SD-OCT) images. Methods: Baseline fluorescein angiography (FA) and SD-OCT images from 1037 treatment-naive study eyes and 531 fellow eyes, without advanced AMD from the phase 3 HARBOR trial (NCT00891735), were used to develop, train, and cross-validate an ML pipeline combining deep-learning–based segmentation of SD-OCT B-scans and CNV classification, based on features derived from the segmentations, in a five-fold setting. FA classification of the CNV phenotypes from HARBOR was used for generating the ground truth for model development. SD-OCT scans from the phase 2 AVENUE trial (NCT02484690) were used to externally validate the ML model. Results: The ML algorithm discriminated CNV absence from CNV presence, with a very high accuracy (area under the receiver operating characteristic [AUROC] = 0.99), and classified occult versus predominantly classic CNV types, per FA assessment, with a high accuracy (AUROC = 0.91) on HARBOR SD-OCT images. Minimally classic CNV was discriminated with significantly lower performance. Occult and predominantly classic CNV types could be discriminated with AUROC = 0.88 on baseline SD-OCT images of 165 study eyes, with CNV from AVENUE. Conclusions: Our ML model was able to detect CNV presence and CNV subtypes on SD-OCT images with high accuracy in patients with neovascular AMD.

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 Is Spectral-Domain Optical Coherence Tomography Essential for Flexible Treatment Regimens with Ranibizumab for Neovascular Age-Related Macular Degeneration?

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Abdullah Ozkaya ◽  
Zeynep Alkin ◽  
Hande Mefkure Ozkaya ◽  
Alper Agca ◽  
Engin Bilge Ozgurhan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Macular Degeneration ◽  
Clinical Examination ◽  
Pigment Epithelium ◽  
Subretinal Fluid ◽  
Age Related Macular Degeneration ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Age Related ◽  
Sd Oct

Purpose. To evaluate the ability of spectral-domain optical coherence tomography to detect subtle amounts of retinal fluid when the choroidal neovascularization is detected as inactive via time-domain optical coherence tomography and clinical examination in neovascular age-related macular degeneration (nAMD) patients.Methods. Forty-nine eyes of 49 patients with nAMD after ranibizumab treatment were included in this cross-sectional, prospective study. All patients were imaged with TD-OCT and SD-OCT at the same visit one month after a ranibizumab injection. The presence of subretinal, intraretinal, and subretinal pigment epithelium fluid (subRPE) in SD-OCT was evaluated; also mean central retinal thickness (CRT) and the rate of vitreoretinal surface disorders detected via the two devices were evaluated.Results. The mean CRT via TD-OCT and SD-OCT was218.1±51.3and325.7±78.8microns. Sixteen patients (32.6%) showed any kind of retinal fluid via SD-OCT. In detail, 8 patients (16.3%) showed subretinal fluid, 10 patients (20.4%) showed intraretinal fluid, and 3 patients (6.1%) showed SubRPE fluid. The ability of detecting vitreoretinal surface disorders was comparable between the two devices, except vitreomacular traction.Conclusion. SD-OCT is essential for the nAMD patients who are on an as-needed treatment regimen with ranibizumab. Only TD-OCT and clinical examination may cause insufficient treatment in this group of patients.

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