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In patients with coronary bifurcation lesions, optical coherence tomography–guided PCI was associated with a lower incidence of major adverse cardiac events at a median 2 years of follow-up than angiography-guided PCI.

Until now, the clinical differentiation between a nevus and a melanoma is still challenging in some cases. Line-field confocal optical coherence tomography (LC-OCT) is a new tool with the aim to change that. The aim of the study was to evaluate LC-OCT for the discrimination between nevi and melanomas. A total of 84 melanocytic lesions were examined with LC-OCT and 36 were also imaged with RCM. The observers recorded the diagnoses, and the presence or absence of the 18 most common imaging parameters for melanocytic lesions, nevi, and melanomas in the LC-OCT images. Their confidence in diagnosis and the image quality of LC-OCT and RCM were evaluated. The most useful criteria, the sensitivity and specificity of LC-OCT vs. RCM vs. histology, to differentiate a (dysplastic) nevus from a melanoma were analyzed. Good image quality correlated with better diagnostic performance (Spearman correlation: 0.4). LC-OCT had a 93% sensitivity and 100% specificity compared to RCM (93% sensitivity, 95% specificity) for diagnosing a melanoma (vs. all types of nevi). No difference in performance between RCM and LC-OCT was observed (McNemar’s p value = 1). Both devices falsely diagnosed dysplastic nevi as non-dysplastic (43% sensitivity for dysplastic nevus diagnosis). The most significant criteria for diagnosing a melanoma with LC-OCT were irregular honeycombed patterns (92% occurrence rate; 31.7 odds ratio (OR)), the presence of pagetoid spread (89% occurrence rate; 23.6 OR) and the absence of dermal nests (23% occurrence rate, 0.02 OR). In conclusion LC-OCT is useful for the discrimination between melanomas and nevi.

Despite the detailed imaging information provided by optical coherence tomography (OCT) during percutaneous coronary intervention (PCI), clinical benefits of this imaging technique in this setting remain uncertain. The aim of the OCCUPI trial was to compare the clinical benefits of OCT-guided versus angiography-guided PCI for complex lesions, assessed as the rate of major adverse cardiac events at 1 year. This investigator-initiated, multicentre, randomised, open-label, superiority trial conducted at 20 hospitals in South Korea enrolled patients aged 19–85 years for whom PCI with drug-eluting stents was clinically indicated. After diagnostic angiography, clinical and angiographic findings were assessed to identify patients who met the criterion of having one or more complex lesions. Patients were randomly assigned 1:1 to receive PCI with OCT guidance (OCT-guidance group) or angiography guidance without OCT (angiography-guidance group). Web-response permuted-block randomisation (mixed blocks of four or six) was used at each participating site to allocate patients. The allocation sequence was computer-generated by an external programmer who was not involved in the rest of the trial. Outcome assessors were masked to group assignment. Patients, follow-up health-care providers, and data analysers were not masked. PCI was done according to conventional standard methods with everolimus-eluting stents. The primary endpoint was major adverse cardiac events (a composite of cardiac death, myocardial infarction, stent thrombosis, or ischaemia-driven target-vessel revascularisation), 1 year after PCI. The primary analysis was done in the intention-to-treat population. The margin used to establish superiority was 1·0 as a hazard ratio. This trial is registered with ClinicalTrials.gov (NCT03625908) and is completed. Between Jan 9, 2019, and Sept 22, 2022, 1604 patients requiring PCI with drug-eluting stents for complex lesions were randomly assigned to receive either OCT-guided PCI (n=803) or angiography-guided PCI (n=801). 1290 (80%) of 1604 patients were male and 314 (20%) were female. The median age of patients at randomisation was 64 years (IQR 57–70). 1588 (99%) patients completed 1-year follow-up. The primary endpoint occurred in 37 (5%) of 803 patients in the OCT-guided PCI group and 59 (7%) of 801 patients in the angiography-guided PCI group (absolute difference –2·8% [95% CI –5·1 to –0·4]; hazard ratio 0·62 [95% CI 0·41 to 0·93]; p=0·023). Rates of stroke, bleeding events, and contrast-induced nephropathy were not significantly different across the two groups. Among patients who required drug-eluting stent implantation for complex lesions, OCT guidance resulted in a lower incidence of major adverse cardiac events at 1 year compared with angiography guidance. These findings indicate the existence of a therapeutic benefit of OCT as an intravascular imaging technique for PCI guidance in patients with complex coronary lesions. Abbott Vascular and Cardiovascular Research Center. For the Korean translation of the abstract see Supplementary Materials section.

In a randomized trial, optical coherence tomography–guided PCI resulted in a larger minimum stent area than angiography-guided PCI, but there was no between-group difference in target-vessel failure at 2 years.

Optical coherence tomography (OCT) based measurements of retinal layer thickness, such as the retinal nerve fibre layer (RNFL) and the ganglion cell with inner plexiform layer (GCIPL) are commonly employed for the diagnosis and monitoring of glaucoma. Previously, machine learning techniques have relied on segmentation-based imaging features such as the peripapillary RNFL thickness and the cup-to-disc ratio. Here, we propose a deep learning technique that classifies eyes as healthy or glaucomatous directly from raw, unsegmented OCT volumes of the optic nerve head (ONH) using a 3D Convolutional Neural Network (CNN). We compared the accuracy of this technique with various feature-based machine learning algorithms and demonstrated the superiority of the proposed deep learning based method. Logistic regression was found to be the best performing classical machine learning technique with an AUC of 0.89. In direct comparison, the deep learning approach achieved a substantially higher AUC of 0.94 with the additional advantage of providing insight into which regions of an OCT volume are important for glaucoma detection. Computing Class Activation Maps (CAM), we found that the CNN identified neuroretinal rim and optic disc cupping as well as the lamina cribrosa (LC) and its surrounding areas as the regions significantly associated with the glaucoma classification. These regions anatomically correspond to the well established and commonly used clinical markers for glaucoma diagnosis such as increased cup volume, cup diameter, and neuroretinal rim thinning at the superior and inferior segments.

To compute choroidal vascularity index (CVI) using an image binarization tool on enhanced depth imaging (EDI)-optical coherence tomography (OCT) scans as a non-invasive optical tool to monitor progression in panuveitis and to investigate the utility of volumetric data from EDI-OCT scans using custom image analysis software. In this retrospective cohort study, segmented EDI-OCT scans of both eyes in 19 patients with panuveitis were taken at baseline and at 3-month follow-up and were compared with EDI-OCT scans of normal eyes. Subfoveal choroidal area was segmented into luminal (LA) and stromal interstitial area (SA). Choroidal vascularity index (CVI) was defined as the proportion of LA to the total circumscribed subfoveal choroidal area (TCA). The mean choroidal thickness was 265.5±100.1μm at baseline and 278.4±102.6μm at 3 months follow up (p = 0.06). There was no statistically significant difference in TCA between study and control eyes (p = 0.08). CVI in the control group was 66.9±1.5% at baseline and 66.4±1.5% at follow up. CVI was 74.1±4.7% at baseline and 69.4±4.8% at 3 months follow up for uveitic eyes (p<0.001). The % change in CVI was 6.2 ±3.8 (4.3 to 8.0) for uveitic eyes, which was significantly higher from % change in CVI for control eyes (0.7±1.1, 0.2 to 1.3, p<0.001). The study reports composite OCT-derived parameters and CVI as a possible novel tool in monitoring progression in panuveitis. CVI may be further validated in larger studies as a novel optical tool to quantify choroidal vascular status.

Migraine is one of the world’s most debilitating disorders, and it has recently been shown that changes in the retina can be a potential biomarker for the disease. These changes can be detected by optical coherence tomography (OCT), which measures retinal thickness, and optical coherence tomography angiography (OCTA), which measures vessel density. We searched the databases Google Scholar, ProQuest, Scopus, and Web of Science for studies in English using OCT and OCTA in migraineurs, using the search terms “optical coherence tomography,” “OCT,” “optical coherence tomography angiography,” “OCTA” and “migraine.” We found 73 primary studies, 11 reviews, and 8 meta-analyses pertaining to OCT and OCTA findings in migraineurs. They showed that migraineurs had reduced retinal thickness (via OCT), retinal vessel density, and greater foveal avascular zone area (via OCTA) than controls. OCTA changes reflect a perfusion compromise occurring in migraineurs as opposed to in healthy controls. OCT and OCTA deficits were worse in migraine-with-aura and chronic migraine than in migraine-without-aura and episodic migraine. Certain areas of the eye, such as the fovea, may be more vulnerable to these perfusion changes than other parts. Direct comparison between study findings is difficult because of the heterogeneity between the studies in terms of both methodology and analysis. Moreover, as almost all case–control studies were cross-sectional, more longitudinal cohort studies are needed to determine cause and effect between migraine pathophysiology and OCT/OCTA findings. Current evidence suggests both OCT and OCTA may serve as retinal markers for migraineurs, and further research in this field will hopefully enable us to better understand the vascular changes associated with migraine, perhaps also providing a new diagnostic and therapeutic biomarker.

Retinal optical coherence tomography (OCT) is an imaging biomarker for neurodegeneration in multiple sclerosis (MS). In order to become validated as an outcome measure in multicenter studies, reliable quality control (QC) criteria with high inter-rater agreement are required. A prospective multicentre study on developing consensus QC criteria for retinal OCT in MS: (1) a literature review on OCT QC criteria; (2) application of these QC criteria to a training set of 101 retinal OCT scans from patients with MS; (3) kappa statistics for inter-rater agreement; (4) identification reasons for inter-rater disagreement; (5) development of new consensus QC criteria; (6) testing of the new QC criteria on the training set and (7) prospective validation on a new set of 159 OCT scans from patients with MS. The inter-rater agreement for acceptable scans among OCT readers (n = 3) was moderate (kappa 0·45) based on the non-validated QC criteria which were entirely based on the ophthalmological literature. A new set of QC criteria was developed based on recognition of: (O) obvious problems, (S) poor signal strength, (C) centration of scan, (A) algorithm failure, (R) retinal pathology other than MS related, (I) illumination and (B) beam placement. Adhering to these OSCAR-IB QC criteria increased the inter-rater agreement to kappa from moderate to substantial (0.61 training set and 0.61 prospective validation). This study presents the first validated consensus QC criteria for retinal OCT reading in MS. The high inter-rater agreement suggests the OSCAR-IB QC criteria to be considered in the context of multicentre studies and trials in MS.

Optical coherence tomography (OCT) systems are traditionally decomposed into engine and scanner components with an expensive and noise-prone analog interface to communicate the scan pattern between the two. Although simple and convenient, analog signals are susceptible to interference and require expensive hardware to generate with appropriate precision for OCT. To overcome these limitations, we implemented a digital interface for our OCT system using low-cost embedded microprocessors and custom PC software, exploiting recent trends toward digital servo drivers for optical scanning. Our interface features USB interfacing with a PC for scan pattern download and position feedback upload, 50-kHz communication rate, external triggers with adjustable downsampling, and no external power requirements. We quantitatively assessed the latency, noise characteristics, and imaging performance of our digital interface in comparison with a conventional analog system that is an order of magnitude more expensive. The signal analysis confirmed that the digital interface reliably transmitted the intended scan pattern to the galvanometer driver and significantly reduced noise in the position feedback signal. High-speed laser trajectory tracking during sparse raster scanning revealed that discrepancies in the analog feedback signal did not reflect actual galvanometer positioning errors; both interfaces achieved equivalent spatial accuracy. Resolution testing demonstrated that both interfaces produced comparable OCT image quality, with no discernible difference up to the system's resolution limit, whereas reconstruction based on digital interface position feedback outperformed other methods when demanding scan patterns, such as spiral scanning, were applied. To support reproducibility and system integration, we developed a custom printed circuit board (PCB), enabling a compact and robust configuration for future OCT deployments. A simplified version of the firmware is supported by our open-source library . Together, these results demonstrate quantitative and qualitative equivalence of the interfaces, despite an order of magnitude reduction in cost. We released open-source software, PCB schematics, design files, and a bill of materials so that the OCT community can benefit from these improvements and cost savings.

This narrative review presents a comprehensive examination of optical coherence tomography angiography (OCTA), a non-invasive retinal vascular imaging technology, as reported in the existing literature. Building on the coherence tomography principles of standard OCT, OCTA further delineates the retinal vascular system, thus offering an advanced alternative to conventional dye-based imaging. OCTA provides high-resolution visualisation of both the superficial and deep capillary networks, an achievement previously unattainable. However, image quality may be compromised by factors such as motion artefacts or media opacities, potentially limiting the utility of OCTA in certain patient cohorts. Despite these limitations, OCTA has various potential clinical applications in managing retinal and choroidal vascular diseases. Still, given its considerable cost implications relative to current modalities, further research is warranted to justify its broader application in clinical practice.