Wide-field OCT Research Articles

Peripheral Superficial Retina Vascular Density and Area of Radial Peripapillary Capillaries Changes in Myopic Individuals: A Wide-Field OCT Angiography Study.

Using swept-source optical coherence tomography (SS-OCT) to explore the effect of high myopia on superficial retina vascular density (SVD) of the peripheral region and the area of radial peripapillary capillaries (RPCs). In this cross-sectional study, a total of 91 volunteers (34 male subjects and 57 female subjects) were recruited and 34 individuals in the high myopic group (group A) and 57 individuals in the low myopic group (group B). Using the wide-field OCT-angiography (OCTA; 24 × 20 mm, 120 degrees angular field) compared the peripheral SVD and the area of RPC between the two groups and investigated its correlation with ocular axial length and diopter. Peripheral SVD of group B around the supratemporal (SVD1), supranasal (SVD2), infratemporal (SVD3), and infranasal (SVD4) directions were significantly higher than those of group A (all P < 0.05). The RPC area of group B around the supranasal (RPC2) and infranasal (RPC4) were significantly larger than that of group A (all P < 0.01). Ocular axial length and diopter were significantly correlated with SVD2 and SVD4 (all P < 0.05), and they also have a significant correlation with the supratemporal (RPC1), RPC2, and RPC4 (all P < 0.05). Peripheral SVD was decreased and the RPC area was mainly reduced on the nasal side in the high myopic group. Peripheral SVD and area of RPC are significantly correlated with ocular axial length and diopter. The wide-field OCTA can be used for new detection of myopia's impact on the retinal peripheral SVD and area of peripapillary RPC, offering new insights into the progression of myopia.

Postoperative Proliferation Detection in Eyes Treated for Rhegmatogenous Retinal Detachment by WideField OCT Angiography.

Proliferative retinal changes may occur postsurgery for rhegmatogenous retinal detachment (RRD), possibly preceding recurrent detachment. This study aims to establish the groundwork for an imaging system capable of discerning changes in retinal vessel tortuosity after RRD repair, analyzing widefield optical coherence tomography angiography (WF-OCTA) images. Eighty-eight eyes of 86 patients with RRD who underwent surgical procedures and had repeated imaging with clear widefield optical coherence tomography (WF-OCT) and WF-OCTA on different postoperative days were enrolled in this retrospective study. We compared WF-OCTA images over time to identify alterations in retinal vessel tortuosity and observed regional changes in retinal morphology. After image processing, changes in retinal vessel tortuosity were detected in 66 quadrants. These changes, attributed to retinal traction from proliferative membranes, were observed in 56 quadrants, among which retinal thickness remained unchanged in seven sectors (12.5%) according to the WF-OCT map. In nine quadrants, changes in retinal vessel tortuosity were attributed to changes in subretinal fluid, aligning with observable variations in retinal thickness. Observation of vessel tortuosity changes using WF-OCTA can help detect early postoperative proliferative changes in eyes with RRD. Because WF-OCTA can detect minute vessel tortuosity changes, it can offer a noninvasive alternative for the detection of early postoperative proliferative changes.

Multi-Plexus Nonperfusion Area Segmentation in Widefield OCT Angiography Using a Deep Convolutional Neural Network.

To train and validate a convolutional neural network to segment nonperfusion areas (NPAs) in multiple retinal vascular plexuses on widefield optical coherence tomography angiography (OCTA). This cross-sectional study included 202 participants with a full range of diabetic retinopathy (DR) severities (diabetes mellitus without retinopathy, mild to moderate non-proliferative DR, severe non-proliferative DR, and proliferative DR) and 39 healthy participants. Consecutive 6 × 6-mm OCTA scans at the central macula, optic disc, and temporal region in one eye from 202 participants in a clinical DR study were acquired with a 70-kHz OCT commercial system (RTVue-XR). Widefield OCTA en face images were generated by montaging the scans from these three regions. A projection-resolved OCTA algorithm was applied to remove projection artifacts at the voxel scale. A deep convolutional neural network with a parallel U-Net module was designed to detect NPAs and distinguish signal reduction artifacts from flow deficits in the superficial vascular complex (SVC), intermediate capillary plexus (ICP), and deep capillary plexus (DCP). Expert graders manually labeled NPAs and signal reduction artifacts for the ground truth. Sixfold cross-validation was used to evaluate the proposed algorithm on the entire dataset. The proposed algorithm showed high agreement with the manually delineated ground truth for NPA detection in three retinal vascular plexuses on widefield OCTA (mean ± SD F-score: SVC, 0.84 ± 0.05; ICP, 0.87 ± 0.04; DCP, 0.83 ± 0.07). The extrafoveal avascular area in the DCP showed the best sensitivity for differentiating eyes with diabetes but no retinopathy (77%) from healthy controls and for differentiating DR by severity: DR versus no DR, 77%; referable DR (rDR) versus non-referable DR (nrDR), 79%; vision-threatening DR (vtDR) versus non-vision-threatening DR (nvtDR), 60%. The DCP also showed the best area under the receiver operating characteristic curve for distinguishing diabetes from healthy controls (96%), DR versus no DR (95%), and rDR versus nrDR (96%). The three-plexus-combined OCTA achieved the best result in differentiating vtDR and nvtDR (81.0%). A deep learning network can accurately segment NPAs in individual retinal vascular plexuses and improve DR diagnostic accuracy. Using a deep learning method to segment nonperfusion areas in widefield OCTA can potentially improve the diagnostic accuracy of diabetic retinopathy by OCT/OCTA systems.

High-speed, long-range and wide-field OCT for in vivo 3D imaging of the oral cavity achieved by a 600 kHz swept source laser.

We report a high-speed, long-range, and wide-field swept-source optical coherence tomography (SS-OCT) system aimed for imaging microstructures and microcirculations in the oral cavity. This system operates at a scan speed of 600 kHz, delivering a wide imaging field of view at 42 × 42 mm2 and a ranging distance of 36 mm. To simultaneously meet the requirements of high speed and long range, it is necessary for the k-clock trigger signal to be generated at its maximum speed, which may induce non-linear phase response in electronic devices due to the excessive k-clock frequency bandwidth, leading to phase errors. To address this challenge, we introduced a concept of electrical dispersion and a global k-clock compensation approach to improve overall performance of the imaging system. Additionally, image distortion in the wide-field imaging mode is also corrected using a method based on distortion vector maps. With this system, we demonstrate comprehensive structural and blood flow imaging of the anterior oral cavity in healthy individuals. The high-speed, long-range, and wide-field SS-OCT system opens new opportunities for comprehensive oral cavity examinations and holds promise as a reliable tool for assessing oral health conditions.

Assessment of Retinal Volume in Individuals Without Ocular Disorders Based on Wide-Field Swept-Source OCT

PurposeTo evaluate retinal volume in eyes without retinal disease using wide-field swept-source optical coherence tomography (SS-OCT). DesignObservational, cross-sectional design ParticipantsA total of 332 eyes of 166 healthy participants. MethodsThe eyes were imaged with OCT-S1 (Canon) using a protocol centered on the fovea cube scans (20 × 23 mm) of SS-OCT images. Retinal volume (6-mm circle, 6–20-mm ring) and various parameters were evaluated in a multivariate analysis using a generalized estimating equation model. Each quadrant of the macula except for the fovea (1–6 mm in diameter) and peripheral ring (6–20 mm in diameter) was also evaluated. Main Outcome MeasureRetinal volume ResultsIn the multivariate analysis, older age and longer axial length were associated with smaller macular retinal volume, whereas older age and left eye were associated with smaller peripheral retinal volume. The temporal area was significantly smaller than all other areas in the macula (1–6 mm), whereas the inferior area was significantly smaller than all other areas in the peripheral retina (6–20 mm). ConclusionsIn wide-field SS-OCT images, age and left eye are negatively correlated with peripheral retinal volume. The thinnest part of the retinal quadrant differs between the macular and peripheral retinas.

Midperipheral retinal thickening on wide field OCT in a patient with a mutation in the NR2E3 gene

Midperipheral retinal thickening on wide field OCT in a patient with a mutation in the NR2E3 gene

Megahertz multi-parametric ophthalmic OCT system for whole eye imaging

An ultrahigh-speed, wide-field OCT system for the imaging of anterior, posterior, and ocular biometers is crucial for obtaining comprehensive ocular parameters and quantifying ocular pathology size. Here, we demonstrate a multi-parametric ophthalmic OCT system with a speed of up to 1 MHz for wide-field imaging of the retina and 50 kHz for anterior chamber and ocular biometric measurement. A spectrum correction algorithm is proposed to ensure the accurate pairing of adjacent A-lines and elevate the A-scan speed from 500 kHz to 1 MHz for retinal imaging. A registration method employing position feedback signals was introduced, reducing pixel offsets between forward and reverse galvanometer scanning by 2.3 times. Experimental validation on glass sheets and the human eye confirms feasibility and efficacy. Meanwhile, we propose a revised formula to determine the “true” fundus size using all-axial length parameters from different fields of view. The efficient algorithms and compact design enhance system compatibility with clinical requirements, showing promise for widespread commercialization.

Double hump appearance of TRD on widefield OCT

Double hump appearance of TRD on widefield OCT

Advantages of the Utilization of Wide-Field OCT and Wide-Field OCT Angiography in Clinical Practice

Wide-field (WF) retinal imaging is becoming a standard diagnostic tool for diseases involving the peripheral retina. Technological progress elicited the advent of wide-field optical coherence tomography (WF-OCT) and WF-OCT angiography (WF-OCTA) examinations. This review presents the results of studies that analyzed the implementation of these procedures in clinical practice and refers to them as traditional and ultra-wide-field fluorescein angiography (UWF-FA). A PUBMED search was performed using the terms WF-OCT OR WF-OCTA OR UWF-FA AND the specific clinical entity, and another search for diabetic retinopathy (DR), retinal vein occlusion (RVO), Coats disease, peripheral retinal telangiectasia, peripheral retinal degeneration, lattice degeneration, and posterior vitreous detachment. The analysis only included the studies in which the analyzed field of view for the OCT or OCTA exam was larger than 55 degrees. The evaluation of the extracted studies indicates that WF imaging with OCT and OCTA provides substantial information on retinal disorders involving the peripheral retina. Vascular diseases, such as DR or RVO, can be reliably evaluated using WF-OCTA with results superior to standard-field fluorescein angiography. Nevertheless, UWF-FA provides a larger field of view and still has advantages over WF-OCTA concerning the evaluation of areas of non-perfusion and peripheral neovascularization. Detailed information on the vascular morphology of peripheral changes should be obtained via WF-OCTA and not angiographic examinations. WF-OCT can serve as a valuable tool for the detection and evaluation of vitreoretinal traction, posterior vitreous detachment, and peripheral retinal degeneration, and guide therapeutic decisions on a patient’s eligibility for surgical procedures.

Comparison of Widefield OCT Angiography Features Between Severe Non-Proliferative and Proliferative Diabetic Retinopathy.

There is a high and ever-increasing global prevalence of diabetic retinopathy (DR) and invasive imaging techniques are often required to confirm the presence of proliferative disease. The aim of this study was to explore the images of a rapid and non-invasive technique, widefield optical coherence tomography angiography (OCT-A), to study differences between patients with severe non-proliferative and proliferative DR (PDR). We conducted an observational longitudinal study from November 2022 to March 2023. We recruited 75 patients who were classified into a proliferative group (28 patients) and severe non-proliferative group (47 patients). Classification was done by specialist clinicians who had full access to any multimodal imaging they required to be confident of their diagnosis, including fluorescein angiography. For all patients, we performed single-shot 4 × 4 and 10 × 10mm (widefield) OCT-A imaging and when possible, the multiple images required for mosaic 17.5 × 17.5mm (ultra widefield) OCT-A imaging. We assessed the frequency with which proliferative disease was identifiable solely from these OCT-A images and used custom-built MATLAB software to analyze the images and determine computerized metrics such as density and intensity of vessels, foveal avascular zone, and ischemic areas. On clinically assessing the OCT-A 10 × 10 fields, we were only able to detect new vessels in 25% of known proliferative images. Using ultra-widefield mosaic images, however, we were able to detect new vessels in 100% of PDR patients. The image analysis metrics of 4 × 4 and 10 × 10mm images did not show any significant differences between the two clinical groups. For mosaics, however, there were significant differences in the capillary density in patients with PDR compared to severe non-PDR (9.1% ± 1.9 in the PDR group versus 11.0% ± 1.9 for severe group). We also found with mosaics a significant difference in the metrics of ischemic areas; average area of ischemic zones (253,930.1 ± 108,636 for the proliferative group versus 149,104.2 ± 55,101.8 for the severe group. Our study showed a high sensitivity for detecting PDR using only ultra-widefield mosaic OCT-A imaging, compared to multimodal including fluorescein angiography imaging. It also suggests that image analysis of aspects such as ischemia levels may be useful in identifying higher risk groups as a warning sign for future conversion to neovascularization.

Practical Utility of Widefield OCT Angiography to Detect Retinal Neovascularization in Eyes with Proliferative Diabetic Retinopathy

To assess the real clinical utility of widefield OCT angiography (WF-OCTA) for detecting retinal neovascularization (RNV) in eyes with proliferative diabetic retinopathy (PDR). A retrospective cross sectional study. Consecutive eyes clinically suspected of PDR by physicians at a tertiary eye center between March 2021 and November2022. All eyes underwent ultrawidefield fluorescein angiography (UWF-FA) (California, Optos) and WF-OCTA (S1, Canon) with a 23× 20 mm scan area. Two independent graders detected individual RNV lesions using UWF-FA and used them as the ground truth. Widefield OCT angiography images were first evaluated to determine whether the images successfully illustrated retinal vasculature, regardless of the image quality index or the presence of vitreous hemorrhage. The graders then identified the RNV lesions with WF-OCTA. We detected RNV by utilizing both the entire retinal slab, including flow signals in the retina, and the custom vitreoretinal interface slab, defined as flow signals from 20 μm below the internal limiting membrane (ILM) to 2000 μm above the ILM. We evaluated the applicability to real clinical practice by not correcting segmentation errors. The success rate of imaging and the detection rate of RNV using WF-OCTA. Initially, 69 consecutive patients who underwent UWF-FA were identified. Of these, 114 eyes from 57 (83%) patients underwent both UWF-FA and WF-OCTA. Of the 114 eyes, 108 (95%) produced gradable WF-OCTA images. Using UWF-FA, the graders identified 175 RNV lesions in 40 eyes. Widefield OCT angiography achieved a sensitivity of 95% and specificity of 88% for detecting eyes with RNV. At the level of individual RNV lesions, graders detected 156 RNV lesions with WF-OCTA, with 118 of these confirmed by UWF-FA (true positive). Among the 57 false-negative lesions, the primary causes were being out of the scan range (26 lesions) and segmentation errors (21 lesions). Widefield OCT angiography imaging had a high success rate, achieving a sensitivity of 95% and a specificity of 88% for detecting eyes with RNV in a real clinical setting. Despite a 67% detection rate for individual RNV lesions, WF-OCTA may serve as a valuable noninvasive method for RNV detection in eyes with diabetic retinopathy. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Inference of Capillary Nonperfusion Progression on Widefield OCT Angiography in Diabetic Retinopathy.

The purpose of this study was to explore the spatial patterns of the nonperfusion areas (NPAs) on widefield optical coherence tomography angiography (OCTA) images in diabetic retinopathy (DR) and to investigate their associations with NPA progression and DR severity. We prospectively enrolled 201 eyes from 158 patients with DR. Widefield images were obtained using a swept-source OCTA device (Xephilio OCT-S1), followed by the creation of 20-mm (1614 pixels) en face images. Nonperfusion squares (NPSs) were defined as 10 × 10-pixel squares without retinal vessels. Eyes with high-dimensional spatial data were mapped onto a two-dimensional space using the uniform manifold approximation and projection algorithm and divided by clustering. The patterns of NPA distribution were statistically compared between clusters. All eyes were mapped onto a two-dimensional space and divided into six clusters based on the similarity of NPA distribution. Eyes in clusters 1 and 2 had minimal and small NPAs, respectively. Eyes in clusters 3 and 4 exhibited NPAs in the temporal and inferotemporal regions, respectively. Eyes in cluster 5 displayed NPAs in both superonasal and inferonasal areas. The unique NPA distributions in each cluster encouraged us to propose eight possible pathways of NPA progression. DR severity was not equal between clusters (P < 0.001), for example, 8 (15.7%) of 51 eyes and 15 (65.2%) of 23 eyes had PDR in clusters 1 and 5, respectively. Dimensionality reduction and subsequent clustering based on the NPA distribution on widefield OCTA enabled the inference of possible NPA progression in DR.

Association of Diabetic Lesions and Retinal Nonperfusion Using Widefield Multimodal Imaging

To evaluate the association of microvascular lesions on ultrawidefield (UWF) color fundus (CF) images with retinal nonperfusion (RNP) up to the midperiphery on single-capture widefield (WF) OCT angiography (OCTA) in patients with diabetic retinopathy (DR). Cross-sectional study. Seventy-five eyes of 50 patients with mild to severe nonproliferative DR (NPDR) and proliferative DR (PDR) were included in this analysis. ETDRS level and presence of predominantly peripheral lesions (PPLs) were assessed on UWF-CF images acquired with a Zeiss Clarus 700. Single-capture 65°-WF-OCTA was performed using a PlexElite prototype (Carl Zeiss Meditec, Inc.). A custom grid consisting of a central ETDRS grid extended by 2 rings reaching up to the midperiphery was overlaid to subdivide retinal areas visible on WF-OCTA en face images. Retinal nonperfusion was measured in each area and in total. Nonperfusion index (NPI) was calculated from total RNP. On UWF-CF images, the number of microaneurysms, hemorrhages, neovascularizations, and areas with intraretinal microvascular abnormalities (IRMAs) were evaluated using the same grid. Association of diabetic lesions with RNP was calculated using Spearman correlations (rs). Median RNP on WF-OCTA was 0 mm2 (0-0.9), 4.9 mm2 (1.9-5.4), 23.4 mm2 (17.8-37), and 68.4 mm2 (40.8-91.7) in mild, moderate, and severe NPDR and PDR, respectively. We found a statistically significant correlation (P < 0.01) of overall RNP (rs= 0.96,) and NPI (rs= 0.97) on WF-OCTA with ETDRS level. Number of grid-fields affected by IRMAs on CF images was highly associated with NPI (rs= 0.86, P < 0.01). Intraretinal microvascular abnormalities and RNPs had similar topographic distributions with high correlations in affected areas. Eyes with PPLs (n= 43 eyes, 57%) on CF images had a significantly higher NPI (P= 0.014) than eyes without PPLs. The combination of UWF-CF imaging and single-capture WF-OCTA allows precise and noninvasive analysis of the retinal vasculature up to the midperiphery in patients with DR. The presence and extent of IRMAs on CF images may serve as an indicator for underlying RNP, which is more pronounced in eyes with PPLs. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Defocus-induced spatial changes in choroidal thickness of chicks observed by wide-field swept-source OCT

Choroid has been claimed to be of importance during ocular development. However, how the choroid responds spatially to different visual cues has not been fully understood. The aim of this study was to investigate defocus-induced spatial changes in choroidal thickness (ChT) in chicks. Eight 10-day-old chicks were fitted monocularly with −10 D or +10 D lenses (day 0), which were removed seven days later (day 7). The ChT was measured on days 0, 7, 14, and 21 using wide-field swept-source optical coherence tomography (SS-OCT) and analyzed with custom-made software. Comparisons of the ChT in the central (1 mm), paracentral (1–3 mm), and peripheral (3–6 mm) ring areas and the ChT in the superior, inferior, nasal, and temporal regions were conducted. Axial lengths and refractions were also evaluated. In the negative lens group, the global ChT of the treated eyes was significantly less than that of the fellow eyes on day 7 (interocular difference: 179.28 ± 25.94 μm, P = 0.001), but thicker on day 21 (interocular difference: 241.80 ± 57.13 μm, P = 0.024). These changes were more pronounced in the central choroid. The superior-temporal choroid changed more during induction but less during recovery. In the positive lens group, the ChT of both eyes increased on day 7 and decreased on day 21, with most changes occurring in the central region, too. The inferior-nasal choroid of the treated eyes changed more during induction but less during recovery. These results provide evidence for regionally asymmetric characteristics of the choroidal response to visual cues and insights into the underlying mechanisms of emmetropization.

Review of Retinal Imaging Modalities for Hydroxychloroquine Retinopathy.

This review provides an overview of conventional and novel retinal imaging modalities for hydroxychloroquine (HCQ) retinopathy. HCQ retinopathy is a form of toxic retinopathy resulting from HCQ use for a variety of autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Each imaging modality detects a different aspect of HCQ retinopathy and shows a unique complement of structural changes. Conventionally, spectral-domain optical coherence tomography (SD-OCT), which shows loss or attenuation of the outer retina and/or retinal pigment epithelium-Bruch's membrane complex, and fundus autofluorescence (FAF), which shows parafoveal or pericentral abnormalities, are used to assess HCQ retinopathy. Additionally, several variations of OCT (retinal and choroidal thickness measurements, choroidal vascularity index, widefield OCT, en face imaging, minimum intensity analysis, and artificial intelligence techniques) and FAF techniques (quantitative FAF, near-infrared FAF, fluorescence lifetime imaging ophthalmoscopy, and widefield FAF) have been applied to assess HCQ retinopathy. Other novel retinal imaging techniques that are being studied for early detection of HCQ retinopathy include OCT angiography, multicolour imaging, adaptive optics, and retromode imaging, although further testing is required for validation.

Окт диагностика скрытого клапанного разрыва при задней отслойке стекловидного тела

Changes in the posterior vitreous that look like hyperreflective dots are considered as a predictor of peripheral retinal breaks in acute posterior vitreous detachment (PVD), along with Shafer's sign, intraretinal and vitreous hemorrhages. Some of peripheral breaks in acute PVD remain unnoticed at the initial ophthalmoscopic examination due to poor visualization. We report a clinical case of an invisible peripheral retinal flap tear detection with overview wide-field OCT (RTVue XR Avanti, Line mode –12 mm) scanning by «sliding» method in the area of retinal hemorrhage in presence of multiple hyperreflective dots in the vitreous during acute symptomatic PVD. Key words: acute PVD; invisible flap tear; wide-field OCT; retinal hemorrhage; stardust sign; hyperreflective dots.

Clinically Significant Nonperfusion Areas on Widefield OCT Angiography in Diabetic Retinopathy

To investigate the distribution of clinically significant nonperfusion areas (NPAs) on widefield OCT angiography (OCTA) images in patients with diabetes. Prospective, cross-sectional, observational study. One hundred and forty-four eyes of 114 patients with diabetes. Nominal 20× 23 mm OCTA images were obtained using a swept-source OCTA device (Xephilio OCT-S1), followed by the creation of en face images 20-mm (1614 pixels) in diameter centering on the fovea. The nonperfusion squares (NPSs) were defined as the 10× 10 pixel squares without retinal vessels, and the ratio of eyes with the NPSs to all eyes in each square was referred to as the NPS ratio. The areas with probabilistic differences (APD) for proliferative diabetic retinopathy (PDR) and nonproliferative diabetic retinopathy (NPDR) (APD[PDR] and APD[NPDR]) were defined as sets of squares with higher NPS ratios in eyes with PDR and NPDR, respectively. The P ratio (NPSs within APD[PDR] but not APD[NPDR]/all NPSs) was also calculated. The probabilistic distribution of the NPSs and the association with diabetic retinopathy (DR) severity. The NPSs developed randomly in eyes with mild and moderate NPDR and were more prevalent in the extramacular areas and the temporal quadrant in eyes with severe NPDR and PDR. The APD(PDR) was distributed mainly in the extramacular areas, sparing the areas around the vascular arcades and radially peripapillary capillaries. The APD(PDR) contained retinal neovascularization more frequently than the non-APD(PDR) (P= 0.023). The P ratio was higher in eyes with PDR than in those with NPDR (P < 0.001). The multivariate analysis designated the P ratio (odds ratio, 8.293× 107; 95% confidence interval, 6.529× 102-1.053× 1013; P= 0.002) and the total NPSs (odds ratio, 1.002; 95% confidence interval, 1.001-1.003; P < 0.001) as independent risk factors of PDR. Most eyes with NPDR and 4-2-1 rule findings of DR severity had higher P ratios but not necessarily greater NPS numbers. The APD(PDR) is uniquely distributed on widefield OCTA images, and the NPA location patterns are associated with DR severity, independent of the entire area of NPAs. Proprietary or commercial disclosure may be found after the references.

Wide-field swept-source OCT angiography (23 × 20mm) for detecting retinal neovascularization in eyes with proliferative diabetic retinopathy.

Xephilio OCT-S1 can capture single-acquisition 23 × 20-mm wide-field swept-source optical coherence tomography angiography (SS-OCTA) images and high-resolution images using artificial intelligence. We aimed to evaluate the ability of wide-field SS-OCTA in the detection of retinal neovascularizations (NVs) in eyes with proliferative diabetic retinopathy (PDR). This retrospective study included 64 eyes of 36 patients (age, 57 ± 10years; 10 female, 26 male) with PDR. All patients underwent a comprehensive ophthalmological examination, including fluorescein angiography (FA), as well as fovea- and disc-centered 23 × 20-mm OCTA imaging (A-scan/B-scan, 928/807). We compared and examined the number of NV sites identified using conventional methods (merging the findings from biomicroscopy/color fundus photography, FA) and the number of NV sites identified using vitreoretinal interface and superficial retinal slabs of wide-field SS-OCTA images, including the position of NVs (nasal upper, nasal lower, temporal upper, temporal lower, or disc). We identified 168 NVs (32/40/45/35/16, in the abovementioned order) using the conventional method. Fovea-centered 23 × 20-mm OCTA images revealed 162 (96%) NVs (27/39/45/35/16). This method tended to miss nasal NV. In contrast, disc-centered 23 × 20-mm OCTA images identified nearly all NVs, detecting 166 (99%) NVs (32/40/44/34/16) in total. All NVs could be visualized using two wide-field OCTA images: fovea- and disc-centered. Wide-field (23 × 20mm) SS-OCTA-especially disc-centered-using Xephilio OCT-S1 identified nearly all NVs in eyes with PDR, with a single acquisition, thereby demonstrating its potential clinical application.

A Prospective, Multicenter, Randomized, Double-Arm Trial to Determine the Impact of the Perimeter B-Series Optical Coherence Tomography and Artificial Intelligence System on Positive Margin Rates in Breast Conservation Surgery

Introduction: Optical coherence tomography (OCT) enables high-resolution, real-time tissue-imaging up to 2mm deep. The Perimeter B-Series OCT System combines wide field-OCT (WF-OCT) with artificial intelligence (AI) to help identify areas suspicious for cancer. The objective of this trial is to assess adjunctive use of WF-OCT and standard care (SOC) in identifying unaddressed positive margins (UPMs). Methods: Prospective, multicenter, randomized, double-arm trial in up to 309 adult women undergoing breast conservation surgery (BCS) for biopsy-confirmed Stage 0-III invasive ductal cancer and/or DCIS, including post-neoadjuvant therapy (NCT05113927). After BCS and SOC intraoperative margin assessment participants will be randomized (2:1) to device or SOC arm. Controls may undergo intraoperative pathology or frozen section analysis, per routine. WF-OCT will be done on all device arm specimens, with an opportunity to excise tissue from the cavity post-analysis, up to 6 total shaves and 2 in each orientation. Results: The study hypothesis is that WF-OCT & AI use will reduce the proportion of subjects with UPM. The primary endpoint is occurrence of ≥1 UPM for a subject; the secondary endpoint is the number of UPMs per subject. Safety includes Adverse Events; false-positive shaves/subject; and BREAST-Q Satisfaction with Breasts. Other outcomes are total excised tissue volume, initial and all procedures; and margin-level effectiveness (sensitivity, specificity, NPV and PPV). Conclusion: Primary endpoint was powered assuming a 15% UPM rate, 90% power, 2:1 allocation, and 10% loss of subjects. Both primary and secondary effectiveness endpoints are based on within-subject comparison of the 2 treatments in the device arm (SOC+WF-OCT).

En face Ultrawidefield OCT of the Vortex Vein System in Central Serous Chorioretinopathy

To investigate whether noninvasive en face ultrawidefield (UWF) OCT can demonstrate salient features of the choroidal vasculature in eyes with central serous chorioretinopathy (CSC). Retrospective observational case series. Patients diagnosed with CSC who underwent UWF indocyanine green angiography (ICGA) and widefield OCT imaging were included. Widefield OCT imaging was performed with a horizontal 23-mm× vertical 20-mm field of view of 5 visual fixations (1 central and 4 peripheral fixations) to compose structural en face UWF OCT montage images and UWF choroidal thickness maps. Automated image alignment was performed before grading. A comparison of choroidal vascular findings seen with UWF ICGA and en face UWF OCT images, including size and distribution of choroidal venous drainage areas and identification of dilated choroidal veins (pachyvessels) crossing the physiologic choroidal watershed zones. The spatial correlation between choroidal vascular hyperpermeability on UWF ICGA images and areas of choroidal thickening on UWF choroidal thickness maps was determined. Forty-two eyes from 27 patients with CSC with a mean age of 56 ± 12 years (range, 31-77 years) were included. Quantitative measures of vortex vein drainage areas on en face UWF OCT images were significantly and positively correlated with those obtained with UWF ICGA (mean Pearson r= 0.825, P < 0.01). Identification of pachyvessels crossing the choroidal watershed zones showed an excellent correlation between UWF ICGA and en face UWF OCT images (mean Spearman ρ= 0.873, P < 0.01). In all cases, choroidal vascular hyperpermeability was observed on UWF ICGA spatially colocalized with areas of choroidal thickening on the UWF choroidal thickness map. Congestion within the entire drainage area of the dominant vortex systems was observed on UWF choroidal thickness maps. In eyes with CSC, noninvasive en face UWF OCT imaging can show distinctive features of choroidal venous insufficiency previously identified with UWF ICGA. Ultrawidefield OCT choroidal thickness maps enable quantitative assessment of choroidal congestion. Proprietary or commercial disclosure may be found after the references.