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Quantifying Disrupted Outer Retinal-Subretinal Layer in SD-OCT Images in Choroidal Neovascularization
摘要： We reported a fully automated method to identify and quantify the thickness of the outer retinal-subretinal (ORSR) layer from clinical spectral-domain optical coherence tomography (SD-OCT) scans of choroidal neovascularization (CNV) due to exudative age-related macular degeneration (eAMD). A total of 23 subjects with CNV met eligibility. Volumetric SD-OCT scans of 23 eyes were obtained (Zeiss Cirrus, 200 3 200 3 1024 voxels). In a subset of eyes, scans were repeated. The OCT volumes were analyzed using our standard parameters and using a 3-dimensional (3D) graph-search approach with an adaptive cost function. A retinal specialist graded the segmentation as generally accurate, local segmentation inaccuracies, or failure. Reproducibility on repeat scans was analyzed using root mean square coef?cient of variation (RMS CV) of the average ORSR thickness. Using a standard segmentation approach, 1/23 OCT segmentations was graded generally accurate and 22/23 were failure(s). With the adaptive method 21/23 segmentations were graded generally accurate; 2/23 were local segmentation inaccuracies and none was a failure. The intermethod quality of segmentation was signi?cantly different (P << 0.001). The average ORSR thickness measured on CNV patients (78.0 lm; 95% con?dence interval [CI], 72.5–83.4 lm) is signi?cantly larger (P << 0.001) than normal average ORSR layer thickness (51.5 6 3.3 lm). The RMS CV was 8.1%. We have developed a fully automated 3D method for segmenting the ORSR layer in SD-OCT of patients with CNV from eAMD. Our method can quantify the ORSR layer thickness in the presence of ?uid, which has the potential to augment management accuracy and ef?ciency of anti-VEGF treatment.
关键词： imaging,OCT,retina,choroidal neovascularization,AMD
更新于2025-09-23 15:21:01
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Influence of Axial Length on Thickness Measurements Using Spectral-Domain Optical Coherence Tomography
摘要： The purpose of this study was to assess the in?uence of axial length on spectral-domain optical coherence tomography (SD-OCT) thickness measurements in patients with subretinal visual implants. Data from eight emmetropic pseudophakic eyes of eight patients with subretinal visual implants were analyzed retrospectively. These patients participated in the monocentric part of a multicenter trial. The axial length was measured in three short (<22.5 mm), three medium (22.51–25.50 mm), and two long (>25.52 mm) eyes. Using Heidelberg Spectralis, the known thickness of a subretinal implant microchip (70 lm) was measured on 15 images per eye with SD-OCT, using the software calipers. The mean axial length was 20.8 6 0.8 mm in short eyes, 23.3 6 0.4 mm in medium eyes, and 26.3 6 0.5 mm in long eyes. We found in short eyes, in medium eyes, and in long eyes a mean value of microchip thickness measurements from SD-OCT of 82.9 6 1.4 lm, 70.5 6 1.3 lm, and 64.2 6 1.3 lm, respectively. The thickness measurements decreased in SD-OCT measurements with longer axial lengths signi?cantly (P < 0.0001). Axial length in?uences SD-OCT thickness measurements. Our ?ndings demonstrate accuracy of the scaling in SD-OCT thickness measurements in emmetropic medium eyes. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. There is a need for larger sample-size studies to con?rm our results.
关键词： subretinal visual implant,spectral-domain optical coherence tomography (SD-OCT),axial length,Heidelberg Spectralis,in vivo measurement
更新于2025-09-23 15:21:01
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Disorganization of Retinal Inner Layers and Ellipsoid Zone Disruption Predict Visual Outcomes in Central Retinal Vein Occlusion
摘要： To assess the associations and predictive value of spectral-domain (SD) OCT inner and outer retinal structural parameters and visual acuity (VA) outcomes in macular edema (ME) secondary to central retinal vein occlusion (CRVO).
关键词： disorganization of retinal inner layers,visual acuity,ellipsoid zone disruption,macular edema,spectral-domain OCT,central retinal vein occlusion
更新于2025-09-23 15:21:01
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Predictive Value of the OCT Double-Layer Sign for Identifying Subclinical Neovascularization in Age-Related Macular Degeneration
摘要： Purpose: Structural optical coherence tomography (OCT) images from eyes with non-exudative age-related macular degeneration (AMD) were graded for the presence of a double layer sign to determine if the double-layer sign predicted subclinical macular neovascularization (MNV). Design: Prospective, observational study. Participants: Non-exudative AMD patients with and without subclinical MNV identified by swept source OCT angiography (SS-OCTA). Methods: Subjects were enrolled prospectively into a SS-OCTA imaging study. A set of test scans with and without subclinical MNV was compiled to assess the ability of trained graders to identify non-exudative type 1 MNV. The graders only evaluated the structural OCT B-scans of those eyes. The presence of a double-layer sign was used as a predictive sign for subclinical type 1 MNV. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) from two separate gradings were calculated and compared. Main Outcome Measures: The association between the presence of a double-layer sign and subclinical type 1 MNV. Results: One hundred eyes with non-exudative AMD from 94 patients were used for this study. The test set contained 64 eyes with intermediate AMD (iAMD), which included 20 eyes with subclinical MNV, and 36 eyes with late AMD, which included 13 eyes with subclinical MNV. Two junior graders read the scans separately then reached a consensus grading. They detected a double-layer sign in 24 out of 33 eyes with subclinical MNV and did not detect a double-layer sign in 56 out of 67 eyes without MNV. Their sensitivity, specificity, PPV, and NPV were 73%, 84%, 69%, and 86%, respectively. The senior grader detected a double-layer sign in 29 out of 33 eyes with subclinical MNV and did not detect a double-layer sign in 58 out of 67 eyes without MNV, achieving a sensitivity, specificity, PPV, and NPV as 88%, 87%, 76%, and 94%, respectively. For all graders, there were statistically significant associations between the type 1 MNV and the double-layer sign (P < 0.001). Conclusions: The double-layer sign on structural OCT B-scans was associated with subclinical type 1 MNV and can be used to identify these lesions with good predictive values in eyes with non-exudative AMD.
关键词： OCT double-layer sign,age-related macular degeneration,SS-OCTA imaging,subclinical neovascularization
更新于2025-09-23 15:21:01
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<p>532-nm Subthreshold Micropulse Laser for the Treatment of Chronic Central Serous Retinopathy</p>
摘要： Introduction: Subthreshold micropulse laser treatment with a 532 nm (532-SML) wavelength has been suggested as a treatment option for the treatment of chronic central serous retinopathy (cCSR). The objective is to present its effects and complications. Methods: We present a retrospective cohort study of cCSR patients submitted to 532-SML. Best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) parameters – central macular thickness, subfoveal outer nuclear layer, external limiting membrane, ellipsoid band, interdigitation band, subretinal ?uid and choroidal thickness – were evaluated before and 12 weeks after treatment. A power of 50%, a duty cycle of 5%, exposure time of 200 ms and a spot size of 160 μm were the applied laser parameters. Results: We included 26 eyes. Overall there were no signi?cant changes in visual acuity (median 0.20 (IQR 0) logMAR before and after treatment) or SD-OCT parameters. However, visual bene?ts occurred in 42.3% (n=11) of the patients and in half of the cases, subretinal ?uid was completely reabsorbed. There were no complications. Conclusion: In this study, 532-SML was overall ineffective on cCSR as it did not lead to signi?cant changes in the overall median visual acuity and SD-OCT parameters. However, some patients may have bene?ted functionally and anatomically from the treatment; further investigation is necessary to understand the potential of 532-SML.
关键词： 532 nm wavelength,subthreshold micropulse laser,outer retina bands,SD-OCT,central serous retinopathy
更新于2025-09-23 15:19:57
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Relationship between macular thickness measurement and signal strength using Stratus optical coherence tomography
摘要： Purpose: To examine the relationship between signal strength and macular thickness as measured by Stratus optical coherence tomography (OCT)'s fast macular thickness protocol in healthy subjects. Methods: In this prospective cross-sectional study 79 eyes of 42 healthy subjects were enrolled. The age, gender, and eye (right vs left) of each subject were recorded. The Stratus OCT fast macular thickness scan protocol was used and the macular thickness was measured with retinal thickness map analysis. Each eye was imaged at least six times to acquire images with signal strengths of 4, 5, 6, 7, 8, and 9 out of 10 via adjustment of the focusing knob. The OCT parameters included in the analysis were thickness in the central 1 mm and in the different quadrants in the 3-mm area. Results: Overall 79 eyes of 42 patients with a mean age of 38.4±12.4 were included. There was no significant difference between the signal strength measurements obtained with different signal strengths in the central thickness (P=0.20). In the superior, nasal, inferior, and temporal quadrants, a signal strength of 8 demonstrated up to 3 μm thicker measurements than a signal strength of 5 (P<0.05). In general linear regression analysis, after accounting for age and gender, signal strength did not remain a significant predictor of thickness in any quadrant. Conclusions: When using fast map macular measurements, a signal strength of 5 is clinically as efficient as a signal strength of 8 in measuring macular thickness in all quadrants. Insisting on higher signal strength may not be necessary.
关键词： retinal thickness,macular thickness,Stratus OCT,fast map macular measurement,signal strength
更新于2025-09-19 17:15:36
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Sudden Occurrence of Roth Spots and Retinal Hemorrhages following Endoscopic Adhesiolysis: An SD-OCT Evaluation
摘要： Purpose: To document the occurrence of Roth spots and retinal hemorrhages by spectral-domain optical coherence tomography (SD-OCT) following endoscopic adhesiolysis for failed back surgery syndrome. Methods: Case report. Results: A 47-year-old patient noted progressive and bilateral visual loss immediately after epidural endoscopy and endoscopic adhesiolysis. Funduscopic examination showed multiple Roth spots and retinal hemorrhages at the posterior pole and the retinal midperiphery in both eyes. Spectral-domain optical coherence tomography demonstrated that Roth spots involved the inner retina, while dot hemorrhages involved the outer retina. Most retinal hemorrhages and Roth spots resolved over 6 weeks, with complete functional recovery in both eyes. However, SD-OCT revealed multiple areas of disruption of the outer retinal layers in the left eye. Conclusions: Roth spots and retinal hemorrhages can occur after endoscopic spinal surgery. Although hemorrhages resolve quickly over few weeks, SD-OCT can demonstrate that retinal damage might persist, especially in the outer retina. This finding may explain cases of incomplete recovery of visual function after complicated endoscopic adhesiolysis.
关键词： Endoscopic adhesiolysis,Optical coherence tomography,Roth spots,SD-OCT,Failed back surgery syndrome
更新于2025-09-19 17:15:36
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Diffuse Retinal Nerve Fiber Layer Defects Identification and Quantification in Thickness Maps
摘要： PURPOSE. To report retinal nerve fiber layer (RNFL) defect identification and quantification in RNFL thickness maps according to the structural RNFL loss, and to evaluate diffuse RNFL defects. METHODS. A total of 170 patients with glaucoma and 186 normal subjects were consecutively enrolled. We defined RNFL defects in an RNFL thickness map by the degree of RNFL loss. The reference level for RNFL defect determination was set as a 20% to 70% degree of RNFL loss with a 1% interval. To identify RNFL defects, each individual RNFL thickness map was compared to the normative database map by using MATLAB software, and the region below the reference level was detected. The area, volume, location, and angular width of each RNFL defect were measured. Diffuse RNFL defects were defined as having an angular width > 30°. RESULTS. The optimal reference level for glaucomatous RNFL defects identification was 42% loss of RNFL. Retinal nerve fiber layer defects were identified in all (100%) of the 170 glaucoma patients and false-positive RNFL defects were detected in 16 (8.16%) cases among the 186 normal subjects. In all, 64.1% of glaucoma patients had diffuse RNFL defects, and 47.7% of diffuse RNFL defects were associated with mild glaucoma patients. The volume of diffuse RNFL defects was significantly associated with the severity of glaucomatous damage (P = 0.009). Diffuse RNFL defects were located closer to the center of the optic disc than localized RNFL defects (P < 0.001). CONCLUSIONS. Retinal nerve fiber layer thickness map analysis is an effective method for analyzing RNFL defects. Quantitative measurements (area, volume, location, and width) were useful to understanding diffuse RNFL defects.
关键词： OCT,diffuse RNFL defect,RNFL thickness map,retinal nerve fiber layer
更新于2025-09-19 17:15:36
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Adaptation Assessment of Three Bonded Resin Restorations at the Cavity Floor Using Cross-Polarization Optical Coherence Tomography
摘要： Objective: The aim of the study was to compare the composite adaptation of three systems by using cross-polarization optical coherence tomography (CP-OCT). Background data: Most polymer-based restorations suffer from polymerization shrinkage that affects the interfacial seal. This shrinkage cannot be detected by conventional X-ray methods. Optical coherence tomography was proved to be a reliable non-invasive imaging tool to examine biological structures and biomaterials at micron scale. Methods: Twenty-four cylindrical class-V cavities were prepared on the buccal surfaces of the extracted human molars. After cavity preparation, samples were randomly divided into three groups (n = 8) according to the restoration system: one-step self-etch Clearfil Tri-S Bond Plus with Clearfil Majesty ES-2 composite (TS; Kuraray Noritake Dental), Single Bond Universal in self-etch mode with Filtek Z350 XT composite (SB; 3M ESPE), and one-step self-etch Palrique Bond with Palrique LX 5 composite (PB; Tokuyama Dental). The restoration placement was carried out according to the manufacturers’ recommendations. Later, the specimens were immersed in a contrasting agent; then, image acquisitions were taken by CP-OCT to calculate the adaptation percentage by using an image analysis software. Results: Mann–Whitney U test showed no statistical significant difference in the adaptation percentage between TS (91.72 – 11.6) and SB (93.43 – 6.9) groups ( p > 0.05). However, the adaptation percentage in PB (41.83 – 28.5) was significantly lower than in the other tested groups ( p < 0.05). Conclusions: Within the limitation of the study, TS and SB groups showed better adaptation than PB. Moreover, CP-OCT is a useful imaging tool that can display composite adaptation at micron scale.
关键词： tooth,OCT,dentin,laser,gap,composite
更新于2025-09-19 17:15:36
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Three-dimensional optical coherence tomography image denoising through multi-input fully-convolutional networks
摘要： In recent years, there has been a growing interest in applying convolutional neural networks (CNNs) to low-level vision tasks such as denoising and super-resolution. Due to the coherent nature of the image formation process, the optical coherence tomography (OCT) images are inevitably affected by noise. This paper proposes a new method named the multi-input fully-convolutional networks (MIFCN) for denoising of OCT images. In contrast to recently proposed natural image denoising CNNs, the proposed architecture allows the exploitation of high degrees of correlation and complementary information among neighboring OCT images through pixel by pixel fusion of multiple FCNs. The parameters of the proposed multi-input architecture are learned by considering the consistency between the overall output and the contribution of each input image. The proposed MIFCN method is compared with the state-of-the-art denoising methods adopted on OCT images of normal and age-related macular degeneration eyes in a quantitative and qualitative manner.
关键词： Multi-input FCN,Optical Coherence Tomography (OCT),Image denoising,Fully convolutional network (FCN)
更新于2025-09-19 17:15:36