Background: Ticks are known as the representatives of hematophagous arachnids. They cause various tick-borne diseases, such as severe fever with thrombocytopenia syndrome (SFTS) and Lyme disease. To understand the mechanism of virus infection caused by ticks, morphology for the anatomical characteristics of crucial organs has been widely studied in acarological fields. The conventional methods used for tick observation have inevitable limitations. Dissection is the standard method to obtain the morphological information, and complex microscopy methods were utilized alternatively. Objective: The study goal is to obtain the morphological information of ticks in different growth stages non-invasively. Methods: Optical coherence tomography (OCT ...

Background: Screening for Alzheimer's disease and related disorders (ADRD) and mild cognitive impairment (MCI) could increase case identification, enhance clinical trial enrollment, and enable early intervention. MCI and ADRD screening would be most beneficial if detection measures reflect neurodegenerative changes. Optical coherence tomography (OCT) could be a marker of neurodegeneration (part of the amyloid-tau-neurodegeneration (ATN) framework). Objective: To determine whether OCT measurements can be used as a screening measure to detect individuals with MCI and ADRD. Methods: A retrospective cross-sectional study was performed on 136 participants with comprehensive clinical, cognitive, functional, and behavioral evaluations including OCT with a subset ...

Abstract: Background:There is increasing evidence that Alzheimer’s disease (AD) patients may present decreased cerebral blood perfusion before pathological brain changes. Using the retina as a window to the brain, we can study disorders of the central nervous system through the eyes. Objective:This study aim ed to investigate differences in retinal structure and vessel density (VD) between patients with mild AD and healthy controls (HCs). Furthermore, we explored the relationship between retinal VD and cognitive function. Methods:We enrolled 37 patients with AD and 29 age-matched HCs who underwent standard ophthalmic optical coherence tomography angiography (OCTA) for evaluation ...

Background: We performed exploratory analyses of retinal thickness data from a clinical trial of the AβPP cleaving enzyme (BACE) inhibitor verubecestat in patients with Alzheimer's disease (AD). Objective: To evaluate: 1) possible retinal thickness changes following BACE inhibition; and 2) possible association between retinal thickness and brain atrophy. Methods: Retinal thickness was measured using spectral-domain optical coherence tomography in a 78-week randomized placebo-controlled trial of verubecestat in 1,785 patients with mild-to-moderate AD. Changes from baseline in retinal pigment epithelium, macular grid retinal nerve fiber layer, central subfield retinal thickness, and macular grid volume were evaluated for verubecestat ...

Exposure to noise trauma, such as that from improvised explosive devices, can lead to sensorineural hearing loss and a reduced quality of life. In order to elucidate the mechanisms underlying noise-induced hearing loss, we have adapted optical coherence tomography (OCT) for real-time cochlear visua lization in live mice after blast exposure. We demonstrated that endolymphatic hydrops develops following blast injury, and that this phenomenon may be associated with glutamate excitotoxicity and cochlear synaptopathy. Additionally, osmotic stabilization of endolymphatic hydrops partially rescues cochlear synapses after blast trauma. OCT is thus a valuable research tool for investigating the mechanisms underlying acoustic trauma ...

Human eye is affected by the different eye diseases including choroidal neovascularization (CNV), diabetic macular edema (DME) and age-related macular degeneration (AMD). This work aims to design an artificial intelligence (AI) based clinical decision support system for eye disease detection and cl assification to assist the ophthalmologists more effectively detecting and classifying CNV, DME and drusen by using the Optical Coherence Tomography (OCT) images depicting different tissues. The methodology used for designing this system involves different deep learning convolutional neural network (CNN) models and long short-term memory networks (LSTM). The best image captioning model is selected after performance analysis by ...

Background:There is a significant current interest in combining multiple modalities in a single optical system for a more complete characterization of tissue for improved diagnosis. Objective:We report development of a dual-modal optical system combing the depth-sensitive laser induced fluorescence (LIF) spectroscopy and optical coherence tomography (OCT) for analysis of layered biological tissues. Methods:A time-domain, real-time OCT system, assembled in-house, was used as the platform for developing the dual-modal system. It involved appropriate modification of the sample arm of the OCT for making the LIF excitation beam (337 nm) collinear with the OCT illumination beam (1310 nm) and ...

BACKGROUND: K-trigger signals from light source or external Mach-Zehnder interferometer are commonly used in swept source optical coherence tomography (SS-OCT) to achieve interference signal sampling and resolution enhancement. But extra signal transmission time is required due to the increased complexity of interference system using k-trigger signals, resulting in a misalignment (a.k.a., time delay) between the k-trigger and the interference signals. OBJECTIVE: The objective of this paper is to propose a numerical technique to correct the time delay between these two signals. METHODS: The time delay is iterated in this technique and each iterated correction result is evaluated through ...

Adaptive optics plays an important role in the correction of high-order aberrations to enhance lateral resolution. An OCT system coupled with a programmable phase modulator is designed to verify lateral resolution improvement. The Hamamatsu high-resolution, non-pixelized, optically addressed light modulator (PAL-SLM) PPM X7550 series is used to correct aberrations, utilizing a simple method based on phase information from OCT images. The advantages of this method are its high simplicity and low cost. A raster scanning technique is adopted to scan samples covered with scattering suspension. Metal lines covered with scattering suspension are imaged, and a respective correction is applied to ...