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Since the advent of artificial intelligence(AI), it has been increasingly applied and rapidly developed in various fields. In the field of medicine, image features can be automatically extracted and the performance of feature learning and classification can be completed with the help of AI. In the field of ocular fundus disease, AI can give a diagnosis of age-related maculopathy by analyzing and identifying fundus photography and optical coherence tomography with an accuracy rate similar to that of ophthalmologists. In the future, AI may assist physicians in making a diagnosis of age-related macular degeneration, aid basic hospital in screening and curb its progression in the early stage of the disease. However, the technique has problems such as uncertain model recognition performance, opaque operation process, and excessive amount of clinical data required, which still cannot be widely used in the clinic. In recent years, a lot of research has been done in China in the application of deep learning with AI to assist diagnosis of ophthalmic diseases, and the results show that AI combined with imaging analysis of ophthalmic diseases has such characteristics as objectivity, efficiency and accuracy. In this article, studies on deep learning in the auxiliary diagnosis of age-related maculopathy are reviewed, and the progress on its application and the limitations that exist are analyzed, so as to provide more information on the use and extension of AI in this disease.

This paper presents a combined optical imaging/artificial intelligence (OI/AI) technique for the real-time analysis of tissue morphology at the tip of the biopsy needle, prior to collecting a biopsy specimen. This is an important clinical problem as up to 40% of collected biopsy cores provide low diagnostic value due to high adipose or necrotic content. Micron-scale-resolution optical coherence tomography (OCT) images can be collected with a minimally invasive needle probe and automatically analyzed using a computer neural network (CNN)-based AI software. The results can be conveyed to the clinician in real time and used to select the biopsy location more adequately. This technology was evaluated on a rabbit model of cancer. OCT images were collected with a hand-held custom-made OCT probe. Annotated OCT images were used as ground truth for AI algorithm training. The overall performance of the AI model was very close to that of the humans performing the same classification tasks. Specifically, tissue segmentation was excellent (~99% accuracy) and provided segmentation that closely mimicked the ground truth provided by the human annotations, while over 84% correlation accuracy was obtained for tumor and non-tumor classification. [ABSTRACT FROM AUTHOR]

Nanodiamonds (NDs) are emerging as a promising candidate for multimodal bioimaging on account of their optical and spectroscopic properties. NDs are extensively utilized for bioimaging probes due to their defects and admixtures in their crystal lattice. There are many optically active defects presented in NDs called color centers, which are highly photostable, extremely sensitive to bioimaging, and capable of electron leap in the forbidden band; further, they absorb or emit light when leaping, enabling the nanodiamond to fluoresce. Fluorescent imaging plays a significant role in bioscience research, but traditional fluorescent dyes have some drawbacks in physical, optical and toxicity aspects. As a novel fluorescent labeling tool, NDs have become the focus of research in the field of biomarkers in recent years because of their various irreplaceable advantages. This review primarily focuses on the recent application progress of nanodiamonds in the field of bioimaging. In this paper, we will summarize the progress of ND research from the following aspects (including fluorescence imaging, Raman imaging, X-ray imaging, magnetic modulation fluorescence imaging, magnetic resonance imaging, cathodoluminescence imaging, and optical coherence tomography imaging) and expect to supply an outlook contribution for future nanodiamond exploration in bioimaging. [ABSTRACT FROM AUTHOR]

To report the presence of bacillary layer detachment (BLD) in unilateral acute idiopathic maculopathy (UAIM). Two patients diagnosed with UAIM based on the clinical and imaging features showed the characteristic splitting of the ellipsoid layer on spectral domain optical coherence tomography (SDOCT). This has been termed as bacillary layer detachment. No treatment was given. In both cases, there was a complete spontaneous resolution of the SDOCT findings 14-days post-presentation in Case 1 and 5-days post-presentation in Case 2 with improvement in visual acuity to 20/20, N6 in both cases. BLD in UAIM is not a commonly reported SDOCT finding and can serve as an imaging biomarker. [ABSTRACT FROM AUTHOR]

The advancement of safe nanomaterials for use as optical coherence tomography (OCT) imaging and stem cell-labeling agents to longitudinally visually track therapeutic derived retinal stem cells to study their migration, survival rate, and efficacy is challenged by instability, intracellular aggregation, low uptake, and cytotoxicity. Here, we describe a series of hybrid lipid-coated gold nanorods (AuNRs) that could solve these issues. These nanomaterials were made via a layer-by-layer assembly approach, and their stability in biological media, mechanism, efficiency of uptake, and toxicity were compared with a commercially available set of AuNRs with a 5 nm mesoporous silica (mSiO2)-polymer coating. These nanomaterials can serve as stem cell labeling and OCT imaging agents because they absorb in the near-infrared (NIR) region away from biological tissues. Although both subtypes of AuNRs were taken up by retinal pigment epithelial, neural progenitor, and baby hamster kidney cells, slightly negatively charged hybrid lipid-coated AuNRs had minimal aggregation in biological media and within the cytoplasm of cells (∼3000 AuNRs/cell) as well as minimal impact on cell health. Hybrid lipid-coated AuNRs modified with cell-penetrating peptides had the least toxicological impact, with >92% cell viability. In contrast, the more "sticky" AuNRs with a 5 nm mSiO2-polymer coating showed significant aggregation in biological media and within the cytoplasm with lower-than-expected uptake of AuNRs (∼5400 of AuNRs/cell) given their highly positive surface charge (35+ mV). Collectively, we have demonstrated that hybrid lipid-coated AuNRs, which absorb in the NIR-II region away from biological tissues, with tuned surface chemistry can label therapeutic derived stem cells with minimal aggregation and impact on cell health as well as enhance uptake for OCT imaging applications. [ABSTRACT FROM AUTHOR]

From the different methodologies to fill microfabricated alkali-metal vapor cells, the rubidium azide (RbN 3) decomposition by UV radiation is a cost-effective solution to produce rubidium (Rb) and nitrogen (N 2). The typical fabrication of the vapor cells is based on silicon and glass bonding, in which the substrates are heated to temperatures between 300 and 450 ºC along with a high electrostatic field (400 – 1000 V) to establish the solid-state connection. However, the RbN 3 compound has been reported to undergo thermal decomposition within the temperature range of 355–395 ºC. In this work, a systematic variation of the bonding temperature (from 200 to 300 ºC) in silicon cavity-based vapor cells is presented to prevent the RbN3 decomposition during the cell fabrication. Considering that the anodic bonding process can be well represented by a simplified equivalent electrical circuit model, we report a maximum bond strength of 6.05 MPa and a lowest time constant τ of 180.03 s for 300 ºC with a simple electrode configuration. A total transferred charge of ≥0.250 mC.mm−2 for temperatures above 225 ºC are indicative of a good quality bond. Interestingly, distinct differences in the failure mode of bonding are observed, in which undamaged bonded interfaces are only observed for temperatures of 275 ºC and above. As a result, a 3 mm diameter vapor cell was successfully fabricated using anodic bonding at 275 ºC. Moreover, and for the first time, optical coherence tomography (OCT) was implemented as an effective and novel technique to investigate the glass-silicon-glass bonding in a MEMS vapor cell, providing a cross-sectional image of the device, in a non-destructive and contactless manner, to ensure the production of reliable and defect-free devices. [Display omitted] • Anodic bonding parameters were studied for fabricating a vapor cell containing RbN 3. • Time-constant was introduced to compare different anodic bonding parameters. • Time-current curves and tensile strength tests were analyzed for bonded samples. • 275 ºC provided a good balance between bonding results and RbN 3 integrity. • OCT was introduced for defect analysis of anodically bonded devices. [ABSTRACT FROM AUTHOR]

With the advent of endovascular therapy, conventional angiography has replaced histology as a diagnostic gold standard for fibromuscular dysplasia (FMD). However, angiographic findings are not precisely diagnostic in isolated focal renal artery stenosis (RAS) in FMD. Optical coherence tomography (OCT) imaging by reflecting in vivo histology may improve the diagnostic accuracy in such cases. Restenosis following balloon angioplasty of RAS in FMD occurs frequently and often requires optimized reintervention. However, the role of OCT in the diagnostic evaluation of focal RAS in FMD and in optimizing the intervention is not well studied. We present a young female with resistant secondary hypertension due to bilateral focal RAS on angiography. In the absence of an angiographic string of beads appearance, the diagnoses remained uncertain. However, OCT imaging diagnosed a multifocal disease with characteristic changes of fibro-medial dysplasia, akin to its histological description in the literature. The patient underwent bilateral balloon angioplasty with good angiographic results. After one year on follow-up, relapse of uncontrolled systemic hypertension occurred due to bilateral restenosis. Despite a satisfactory repeat balloon angioplasty of the left-sided re-stenotic lesion, a significant residual pressure gradient persisted. Usage of OCT guided oversized balloon and stent safely achieved good results with complete resolution of the pressure gradient. Right renal artery stenosis required balloon angioplasty alone. She had complete resolution of hypertension without any medications at six months of follow-up. In conclusion, OCT can supplement other diagnostic modalities in providing a proper diagnosis in an angiographically ambiguous focal RAS in FMD. A persistent residual pressure gradient across the lesion despite good angiographic results may be optimized with OCT guidance during the intervention. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is a noninvasive bio‐imaging modality that is widely used in both fundamental research and clinical practice. Contrast agents with strong light‐scattering properties are a prerequisite for OCT imaging. Bio‐imaging in the second near‐infrared window (NIR‐II, 1000–1700 nm) has recently attracted significant attention based on reduced light absorption, suppressed photon scattering, and negligible autofluorescence. OCT contrast agents with both strong light‐scattering cross‐sections in the NIR‐II window and excellent biocompatibility are highly desirable. In this article, Ag‐based rod‐shaped plasmonic nanostructures are presented as NIR‐II OCT contrast agents. As a high‐aspect‐ratio heterostructure, the Ag nanorods coated with mesoporous silica shells (AgNR@mSiO2) are developed to achieve plasmon resonance at 1330 nm and excellent biocompatibility. By taking advantage of their huge light‐scattering cross‐sections, which provide the strongest scattering reported to date among various nanoscale OCT contrast agents, the heterostructures are used to perform efficient in vivo OCT imaging of crucian carp eyes and chicken blood vessels in the NIR‐II window. The captured images exhibit enhanced contrast with large imaging depth. These results demonstrate that the developed AgNR@mSiO2 heterostructures are promising OCT contrast agents, that can provide guidance and reference for the development of highly efficient NIR‐II imaging probes. [ABSTRACT FROM AUTHOR]

Longitudinal stent deformation (LSD) is a rare complication but can occur during coronary intervention. We report a case with LSD of the distal edge, documented by an optical coherence tomography investigation and successfully recovered.

Longitudinal stent deformation (LSD) is a rare complication but can occur during coronary intervention. We report a case with LSD of the distal edge, documented by an optical coherence tomography investigation and successfully recovered. [ABSTRACT FROM AUTHOR]

Skin optical clearing can significantly enhance the ability of biomedical optical imaging. Some alcohols and sugars have been selected to be optical clearing agents (OCAs). In this work, we paid attention to the optical clearing potential of disaccharides. Sucrose and maltose were chosen as typical disaccharides to compare with fructose, an excellent monosaccharide-OCA, by using molecular dynamics simulation and an ex vivo experiment. The experimental results indicated that the optical clearing efficacy of skin increases linearly with the concentration for each OCA. Both the theoretical predication and experimental results revealed that the two disaccharides exerted a better optical clearing potential than fructose at the same concentration, and sucrose is optimal. Since maltose has an extremely low saturation concentration, the other two OCAs with saturation concentrations were treated topically on rat skin in vivo, and optical coherence tomography imaging was applied to monitor the optical clearing process. The results demonstrated that sucrose could cause a more significant increase in imaging depth and signal intensity than fructose. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the concept of using high-resolution optical coherence tomography (OCT) imaging to rapidly assess surgical specimens and determine if cancer positive margins were left behind in the surgical bed. A mouse model of breast cancer was used in this study. Surgical specimens from 30 animals were investigated with OCT and automated interpretation of the OCT images was performed and tested against histopathology findings. Specimens from 10 animals were used to build a training set of OCT images, while the remaining 20 specimens were used for a validation set of images. The validation study showed that automated interpretation of OCT images can differentiate tissue types and detect cancer positive margins with at least 81 % sensitivity and 89% specificity. The findings of this pilot study suggest that OCT imaging of surgical specimens and automated interpretation of OCT data may enable in the future real-time feedback to the surgeon about margin status in patients with breast cancer, and potentially with other types of cancers. Currently, such feedback is not provided and if positive margins are left behind, patients have to undergo another surgical procedure. Therefore, this approach can have a potentially high impact on breast surgery outcome. [ABSTRACT FROM AUTHOR]

Aims Recent data have reported that neoatherosclerosis could develop long after stent implantation and lead to subsequent rupture and acute coronary syndrome (ACS). We sought to identify the presence of in-stent neoatheroma (ISNA) in patients with very late stent thrombosis (VLST) using optical coherence tomography (OCT). Methods and results All patients from two catheterization centres who presented with ACS related to VLST underwent a standard coronary angiography and intra-coronary OCT. ISNA was defined as the combination of diffuse neointimal proliferation, lipid-laden intima with plaque organization, and fibrous cap rupture with no evidence of an uncovered strut. Conclusion Our data show that ISNA is frequent in patients with VLST. These results suggest that OCT imaging is helpful in identifying the underlying mechanisms of VLST and, therefore, in the clinical decision-making process. [ABSTRACT FROM PUBLISHER]

Precise positioning of a stimulating electrode in the eye is not possible by simple visualization. However, reliable measurement of responses to retinal stimulation requires consistent positioning. The present study focuses on impedance measurement techniques to sense the proximity of the electrode to the retina. A platinum-iridium stimulation electrode was placed inside the rat eye and impedance was recorded at different positions of the stimulating electrode relative to the retina. The presence of robust electrically evoked response in the superior colliculus indicates that the electrode may not have to be in absolute contact in order to elicit a neural response. Optical coherence tomography imaging confirmed the distance-impedance relationship. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is a method of high-resolution imaging originally developed for the transparent tissue of the eye. Recently, the technology has been advanced toward the difficult challenge of imaging in nontransparent tissue. In the paper, three topics are addressed. First, the principles behind OCT imaging are discussed. Second, the difficulties associated with OCT imaging in nontransparent tissue are outlined. Finally, the feasibility of OCT for medical imaging is discussed. Specifically, OCT demonstrates its greatest potential in situations where conventional biopsy is either dangerous or ineffective [ABSTRACT FROM PUBLISHER]

Aims: Recent data have reported that neoatherosclerosis could develop long after stent implantation and lead to subsequent rupture and acute coronary syndrome (ACS). We sought to identify the presence of in-stent neoatheroma (ISNA) in patients with very late stent thrombosis (VLST) using optical coherence tomography (OCT)., Methods and Results: All patients from two catheterization centres who presented with ACS related to VLST underwent a standard coronary angiography and intra-coronary OCT. ISNA was defined as the combination of diffuse neointimal proliferation, lipid-laden intima with plaque organization, and fibrous cap rupture with no evidence of an uncovered strut. Out of 2139 ACS patients, 20 presented with definite VLST, including 10 with evidence of ISNA lesions, detected using OCT. The mean delay between initial percutaneous coronary intervention and VLST was longer in the ISNA patients compared with non-ISNA patients (10.5 ± 1.6 vs. 4.0 ± 0.6 years, P = 0.003). The mean LDL-cholesterol tended to be higher in ISNA patients compared with non-ISNA patients. OCT analysis revealed significantly thicker neointimal coverage as well as a lower number of uncovered struts in ISNA lesions compared with the other patients. LDL-cholesterol levels were correlated with the average neointima thickness (Spearman's rho = 0.46, P = 0.04). All the ISNA lesions were treated through initial thrombectomy followed by redo stenting in nine patients., Conclusion: Our data show that ISNA is frequent in patients with VLST. These results suggest that OCT imaging is helpful in identifying the underlying mechanisms of VLST and, therefore, in the clinical decision-making process.