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1.
J. optom. (Internet) ; 17(2): [100485], Abr-Jun, 2024. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-231620

RESUMO

Purpose: To study topographic epithelial and total corneal thickness changes in myopic subjects undergoing successful orthokeratology treatment in connection with the objective assessment of contact lens decentration. Methods: A prospective-observational and non-randomized study in 32 Caucasian myopic eyes undergoing Ortho-k for 3 months. Total, epithelial, and stromal thicknesses were studied before and after Ortho-k treatment, using optical coherence tomography with anterior segment application software. Central, paracentral, and mid-peripheral values are taken along 8 semi-meridians. Results: The central average total corneal thickness was 4.72 ± 1.04 μm thinner after Ortho-K. The paracentral corneal thickness showed no significant changes (p = 0.137), while the mid-peripheral corneal thickness was increased by 3.25 ± 1.6 μm associating this increase exclusively to the epithelial plot (p<0.001). When lens centration was assessed, a lens fitting decentration less than 1.0 mm was found for the whole sample, predominantly horizontal-temporal (87.5%) and vertical-inferior (50%) decentring. Corneal topographical analysis revealed a horizontal and vertical epithelial thickness asymmetric change profile with paracentral temporal thinnest values, and mid-peripheral nasal thickest values. Conclusions: The present study found a central corneal thinning induced by Ortho-k lenses in subjects with moderate myopia, only associated with a change in epithelial thickness, as well as mid-peripheral thickening, that seems to be mainly epithelial in origin. The authors also found a tendency of contact lens decentration toward temporal and inferior areas conditioning an asymmetric epithelial redistribution pattern.(AU)


Assuntos
Humanos , Masculino , Feminino , Visão Ocular , Miopia , Cristalino , Procedimentos Ortoceratológicos , Substância Própria , Tomografia de Coerência Óptica , Estudos Retrospectivos , Optometria , Oftalmologia , Estudos Prospectivos
2.
J Nepal Health Res Counc ; 21(4): 603-609, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38616590

RESUMO

BACKGROUND: To evaluate the Retinal Nerve Fiber Layer and Ganglion Cell Complex thickness using Spectral Domain Optical Coherence Tomography with and without positive family history of Primary Open Angle Glaucoma and its relation to visual field. METHODS: Total 120 eyes with each subjects with positive family history of Primary Open Angle Glaucoma (Group I, n=30) and healthy subjects without positive family history of Primary Open Angle Glaucoma (Group II, n=30) undergone complete ophthalmic evaluation with Retinal Nerve Fiber Layer, Ganglion Cell Complex and VF obtained from Spectral Domain Optical Coherence Tomography RTVue-100 and Humphrey visual field respectively .The measurements were analyzed and compared among two groups using independent-t test by using SPSS version 23.The relationship of Retinal Nerve Fiber Layer with visual field were evaluated with correlation analysis. RESULTS: There were 75 patients included in the study.nasal, temporal RNFL and average Ganglion Cell Complex was significantly lower and thinner in Group I with mean difference of -8.53±2.30 µm (p<0.001), -7.35±3.34 µm (p<0.001), -8.52±3.58µm (p<0.001),-11.87±2.24µm (p<0.001), -5.31±1.95µm (p<0.001) and -8.05±1.52µm (p<0.001) respectively. Correlation plot with Retinal Nerve Fiber Layer thickness as predictor of Mean Deviation and Pattern Standard Deviation indicated statistically significant degree of determination in Group I (r=0.455 and r=0.623, p<0.001 and p<0.001). CONCLUSIONS: The Optical Coherence Tomography and visual field Parameters are lower in group I and used as an early predictor, diagnosis, monitoring and management.


Assuntos
Glaucoma de Ângulo Aberto , Glaucoma , Humanos , Tomografia de Coerência Óptica , Campos Visuais , Glaucoma de Ângulo Aberto/diagnóstico por imagem , Nepal
3.
Sci Rep ; 14(1): 8724, 2024 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-38622152

RESUMO

The objective of this study is to define structure-function relationships of pathological lesions related to age-related macular degeneration (AMD) using microperimetry and multimodal retinal imaging. We conducted a cross-sectional study of 87 patients with AMD (30 eyes with early and intermediate AMD and 110 eyes with advanced AMD), compared to 33 normal controls (66 eyes) recruited from a single tertiary center. All participants had enface and cross-sectional optical coherence tomography (Heidelberg HRA-2), OCT angiography, color and infra-red (IR) fundus and microperimetry (MP) (Nidek MP-3) performed. Multimodal images were graded for specific AMD pathological lesions. A custom marking tool was used to demarcate lesion boundaries on corresponding enface IR images, and subsequently superimposed onto MP color fundus photographs with retinal sensitivity points (RSP). The resulting overlay was used to correlate pathological structural changes to zonal functional changes. Mean age of patients with early/intermediate AMD, advanced AMD and controls were 73(SD = 8.2), 70.8(SD = 8), and 65.4(SD = 7.7) years respectively. Mean retinal sensitivity (MRS) of both early/intermediate (23.1 dB; SD = 5.5) and advanced AMD (18.1 dB; SD = 7.8) eyes were significantly worse than controls (27.8 dB, SD = 4.3) (p < 0.01). Advanced AMD eyes had significantly more unstable fixation (70%; SD = 63.6), larger mean fixation area (3.9 mm2; SD = 3.0), and focal fixation point further away from the fovea (0.7 mm; SD = 0.8), than controls (29%; SD = 43.9; 2.6 mm2; SD = 1.9; 0.4 mm; SD = 0.3) (p ≤ 0.01). Notably, 22 fellow eyes of AMD eyes (25.7 dB; SD = 3.0), with no AMD lesions, still had lower MRS than controls (p = 0.04). For specific AMD-related lesions, end-stage changes such as fibrosis (5.5 dB, SD = 5.4 dB) and atrophy (6.2 dB, SD = 7.0 dB) had the lowest MRS; while drusen and pigment epithelial detachment (17.7 dB, SD = 8.0 dB) had the highest MRS. Peri-lesional areas (20.2 dB, SD = 7.6 dB) and surrounding structurally normal areas (22.2 dB, SD = 6.9 dB) of the retina with no AMD lesions still had lower MRS compared to controls (27.8 dB, SD = 4.3 dB) (p < 0.01). Our detailed topographic structure-function correlation identified specific AMD pathological changes associated with a poorer visual function. This can provide an added value to the assessment of visual function to optimize treatment outcomes to existing and potentially future novel therapies.


Assuntos
Degeneração Macular , Humanos , Estudos Transversais , Estudos Prospectivos , Degeneração Macular/diagnóstico por imagem , Tomografia de Coerência Óptica , Angiofluoresceinografia , Relação Estrutura-Atividade
4.
Int Ophthalmol ; 44(1): 183, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627308

RESUMO

PURPOSE: To assess the positive effects of mindfulness-based stress reduction (MBSR) on the structural and functional outcomes of patients with central serous chorioretinopathy (CSCR). METHODS: This study included 60 patients with CSCR who were randomly allocated to one of two groups: MBSR or control (which did not practice MBSR). These groups were then evaluated in terms of best corrected visual acuity (BCVA) and central macular thickness (CMT) at months 1, 3, and 6. RESULTS: There were no significant differences in BCVA or mean CMT between the groups at the beginning of the study (p = 0.615 and p = 0.561, respectively). There were statistically significant differences between the groups in terms of BCVA at 1, 3, and 6 months (p = 0.018, p = 0.001, and p = 0.002, respectively). There were also significant differences in the mean CMT across the groups at the first, third, and sixth months (p < 0.001, p = 0.001, and p < 0.001, respectively). CONCLUSION: MBSR may have beneficial outcomes in the early treatment of patients with CSCR, resulting in faster resolution of subretinal fluid and enhancement of BCVA.


Assuntos
Coriorretinopatia Serosa Central , Atenção Plena , Humanos , Coriorretinopatia Serosa Central/diagnóstico , Coriorretinopatia Serosa Central/terapia , Angiofluoresceinografia , Doença Aguda , Acuidade Visual , Tomografia de Coerência Óptica/métodos , Estudos Retrospectivos
5.
Transl Vis Sci Technol ; 13(4): 24, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38630469

RESUMO

Purpose: To investigate the topographic characters of inter-individual variations of the macular choroidal thickness (CT). Methods: This was a retrospective study. Macular CT data for 900 0.2 × 0.2-mm grids from 410 healthy eyes were collected from swept-source optical coherence tomography. Following the analysis of factors associated with mean CT, the ß-coefficients of the included associated factors in each grid were summarized for choroidal thickness changes analysis. Additionally, the coefficient of variance (CoV), coefficient of determination (CoD), and coefficient of variance unexplained (CoVU) for CT were calculated in each individual grid to investigate the inter-individual choroidal variations pattern. Results: Sex (ß = -17.26, female vs. male), age (ß = -1.61, per 1 year), and axial length (ß = -18.62, per 1 mm) were associated with mean macular CT. Females had a thinner choroid in all 900 grids (0.5-26.9 µm). As age increased, the CT noticeably decreased (8.74-19.87 µm per 10 years) in the temporal regions. With axial length elongation, the thinning (7.94-24.91 µm per 1 mm) was more evident in subfoveal and nasal regions. Both the CoV (34.69%-58.00%) and CoVU (23.05%-40.78%) were lower in the temporal regions, whereas the CoD (18.41%-39.66%) was higher in the temporal regions. Conclusions: Choroidal thinning is more predominant in the subfoveal and nasal regions with axial length elongation, but in the temporal region with aging. The inter-individual variation of CT is higher and less determined by sex, age, or axial length in the nasal regions. Translational Relevance: Topographic variation should be considered when interpreting choroidal thickness.


Assuntos
Corioide , Tomografia de Coerência Óptica , Feminino , Masculino , Humanos , Criança , Estudos Retrospectivos , Corioide/diagnóstico por imagem
6.
Exp Dermatol ; 33(4): e15057, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38623958

RESUMO

Non-invasive diagnostics like line-field confocal optical coherence tomography (LC-OCT) are being implemented in dermato-oncology. However, unification of terminology in LC-OCT is lacking. By reviewing the LC-OCT literature in the field of dermato-oncology, this study aimed to develop a unified terminological glossary integrated with traditional histopathology. A PRISMA-guided literature-search was conducted for English-language publications on LC-OCT of actinic keratosis (AK), keratinocyte carcinoma (KC), and malignant melanoma (MM). Study characteristics and terminology were compiled. To harmonize LC-OCT terminology and integrate with histopathology, synonymous terms for image features of AK, KC, and MM were merged by two authors, organized by skin layer and lesion-type. A subset of key LC-OCT image-markers with histopathological correlates that in combination were typical of AK, squamous cell carcinoma in situ (SCCis), invasive squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and MM in traditional histopathology, were selected from the glossary by an experienced dermatopathologist. Seventeen observational studies of AK (7 studies), KC (13 studies), MM (7 studies) utilizing LC-OCT were included, with 117 terms describing either AK, KC, or MM. These were merged to produce 45 merged-terms (61.5% reduction); 5 assigned to the stratum corneum (SC), 23 to the viable epidermis, 2 to dermo-epidermal junction (DEJ) and 15 to the dermis. For each lesion, mandatory key image-markers were a well-defined DEJ and presence of mild/moderate but not severe epidermal dysplasia for AK, severe epidermal dysplasia and well-defined DEJ for SCCis, interrupted DEJ and/or dermal broad infiltrative strands for invasive SCC, dermal lobules connected and/or unconnected to the epidermis for BCC, as well as single atypical melanocytes and/or nest of atypical melanocytes in the epidermis or dermis for MM. This review compiles evidence on LC-OCT in dermato-oncology, providing a harmonized histopathology-integrated terminology and key image-markers for each lesion. Further evaluation is required to determine the clinical value of these findings.


Assuntos
Carcinoma Basocelular , Carcinoma de Células Escamosas , Ceratose Actínica , Melanoma , Neoplasias Cutâneas , Humanos , Tomografia de Coerência Óptica/métodos , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/patologia , Ceratose Actínica/diagnóstico por imagem , Ceratose Actínica/patologia , Melanoma/diagnóstico por imagem , Melanoma/patologia , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Carcinoma Basocelular/diagnóstico por imagem
7.
Int Ophthalmol ; 44(1): 180, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38625598

RESUMO

PURPOSE: The main treatment for macular hole (MH) is pars plana vitrectomy, with or without internal limiting membrane (ILM) peeling, followed by gas tamponade and face-down positioning (FDP). This study aims to present the anatomical and visual outcomes following MH repair with optical coherence tomography (OCT)-guided FDP. METHODS: Thirty-two patients who underwent surgery for idiopathic MH were enrolled. The requirement for the prone position was lifted for those with MH closure observed under gas on postoperative day one OCT. Patients with unclosed MHs were instructed to maintain FDP until the 3rd day. Best-corrected visual acuity at preoperative, postoperative 1st month, and the last visit, closure time post-surgery, duration of prone position, and surgical success rate were recorded. RESULTS: Among the patients, 21 underwent phacovitrectomy + ILM peeling + gas tamponade, while 11 had vitrectomy + ILM peeling + gas tamponade. On postoperative day one, 28 out of 32 MHs closed, with 3 closures on day 3 and one on day 5. There were 18 stage two (56.3%), 13 stage three (40.6%) and 1 stage four (3.1%) MHs. The mean minimum MH diameter was 381.75 ± 68.07 (min 260-max 517) microns. All patients with MH closure time over postoperative day one had non-combined vitrectomy instead of phacovitrectomy. No late complications were observed. CONCLUSIONS: OCT-guided FDP approach yields excellent closure rates with no late complications and ensures good patient comfort.


Assuntos
Perfurações Retinianas , Humanos , Perfurações Retinianas/diagnóstico , Perfurações Retinianas/cirurgia , Tomografia de Coerência Óptica , Seguimentos , Período Pós-Operatório , Vitrectomia
8.
Sci Data ; 11(1): 365, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605088

RESUMO

Optical coherence tomography (OCT) is a non-invasive imaging technique with extensive clinical applications in ophthalmology. OCT enables the visualization of the retinal layers, playing a vital role in the early detection and monitoring of retinal diseases. OCT uses the principle of light wave interference to create detailed images of the retinal microstructures, making it a valuable tool for diagnosing ocular conditions. This work presents an open-access OCT dataset (OCTDL) comprising over 2000 OCT images labeled according to disease group and retinal pathology. The dataset consists of OCT records of patients with Age-related Macular Degeneration (AMD), Diabetic Macular Edema (DME), Epiretinal Membrane (ERM), Retinal Artery Occlusion (RAO), Retinal Vein Occlusion (RVO), and Vitreomacular Interface Disease (VID). The images were acquired with an Optovue Avanti RTVue XR using raster scanning protocols with dynamic scan length and image resolution. Each retinal b-scan was acquired by centering on the fovea and interpreted and cataloged by an experienced retinal specialist. In this work, we applied Deep Learning classification techniques to this new open-access dataset.


Assuntos
Aprendizado Profundo , Retina , Doenças Retinianas , Tomografia de Coerência Óptica , Humanos , Retinopatia Diabética/diagnóstico por imagem , Edema Macular/diagnóstico por imagem , Retina/diagnóstico por imagem , Doenças Retinianas/diagnóstico por imagem
9.
Sci Rep ; 14(1): 8484, 2024 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605115

RESUMO

This study aimed to automatically detect epiretinal membranes (ERM) in various OCT-scans of the central and paracentral macula region and classify them by size using deep-neural-networks (DNNs). To this end, 11,061 OCT-images were included and graded according to the presence of an ERM and its size (small 100-1000 µm, large > 1000 µm). The data set was divided into training, validation and test sets (75%, 10%, 15% of the data, respectively). An ensemble of DNNs was trained and saliency maps were generated using Guided-Backprob. OCT-scans were also transformed into a one-dimensional-value using t-SNE analysis. The DNNs' receiver-operating-characteristics on the test set showed a high performance for no-ERM, small-ERM and large-ERM cases (AUC: 0.99, 0.92, 0.99, respectively; 3-way accuracy: 89%), with small-ERMs being the most difficult ones to detect. t-SNE analysis sorted cases by size and, in particular, revealed increased classification uncertainty at the transitions between groups. Saliency maps reliably highlighted ERM, regardless of the presence of other OCT features (i.e. retinal-thickening, intraretinal pseudo-cysts, epiretinal-proliferation) and entities such as ERM-retinoschisis, macular-pseudohole and lamellar-macular-hole. This study showed therefore that DNNs can reliably detect and grade ERMs according to their size not only in the fovea but also in the paracentral region. This is also achieved in cases of hard-to-detect, small-ERMs. In addition, the generated saliency maps can be used to highlight small-ERMs that might otherwise be missed. The proposed model could be used for screening-programs or decision-support-systems in the future.


Assuntos
Membrana Epirretiniana , Humanos , Membrana Epirretiniana/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Estudos Retrospectivos , Acuidade Visual , Redes Neurais de Computação
10.
Cells ; 13(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38607034

RESUMO

The aim of this article is to describe sustained myopic eye growth's effect on astrocyte cellular distribution and its association with inner retinal layer thicknesses. Astrocyte density and distribution, retinal nerve fiber layer (RNFL), ganglion cell layer, and inner plexiform layer (IPL) thicknesses were assessed using immunochemistry and spectral-domain optical coherence tomography on seventeen common marmoset retinas (Callithrix jacchus): six induced with myopia from 2 to 6 months of age (6-month-old myopes), three induced with myopia from 2 to 12 months of age (12-month-old myopes), five age-matched 6-month-old controls, and three age-matched 12-month-old controls. Untreated marmoset eyes grew normally, and both RNFL and IPL thicknesses did not change with age, with astrocyte numbers correlating to RNFL and IPL thicknesses in both control age groups. Myopic marmosets did not follow this trend and, instead, exhibited decreased astrocyte density, increased GFAP+ spatial coverage, and thinner RNFL and IPL, all of which worsened over time. Myopic changes in astrocyte density, GFAP+ spatial coverage and inner retinal layer thicknesses suggest astrocyte template reorganization during myopia development and progression which increased over time. Whether or not these changes are constructive or destructive to the retina still remains to be assessed.


Assuntos
Miopia , Células Ganglionares da Retina , Animais , Astrócitos , Fibras Nervosas , Retina , Tomografia de Coerência Óptica/métodos , Callithrix
11.
Opt Express ; 32(6): 10329-10347, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571248

RESUMO

Optical coherence tomography (OCT) and its extension OCT angiography (OCTA) have become essential clinical imaging modalities due to their ability to provide depth-resolved angiographic and tissue structural information non-invasively and at high resolution. Within a field of view, the anatomic detail available is sufficient to identify several structural and vascular pathologies that are clinically relevant for multiple prevalent blinding diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and vein occlusions. The main limitation in contemporary OCT devices is that this field of view is limited due to a fundamental trade-off between system resolution/sensitivity, sampling density, and imaging window dimensions. Here, we describe a swept-source OCT device that can capture up to a 12 × 23-mm field of view in a single shot and show that it can identify conventional pathologic features such as non-perfusion areas outside of conventional fields of view. We also show that our approach maintains sensitivity sufficient to visualize novel features, including choriocapillaris morphology beneath the macula and macrophage-like cells at the inner limiting membrane, both of which may have implications for disease.


Assuntos
Retinopatia Diabética , Vasos Retinianos , Humanos , Vasos Retinianos/patologia , Angiofluoresceinografia , Tomografia de Coerência Óptica/métodos , Retina
12.
Sci Rep ; 14(1): 8623, 2024 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-38616196

RESUMO

Idiopathic intracranial hypertension (IIH) may result in optic nerve fiber loss and even atrophy. The timing of the optical coherence tomography (OCT) indices reaching the lowest point (nadir) and the factors that predict the patient's anatomical outcome are not known. We aimed to determine the timing and the factors that affect nadir retinal nerve fiber layer (RNFL) thickness. The medical records of 99 IIH patients who were treated from December 2009 to January 2020 were retrospectively reviewed. The mean RNFL thickness at presentation was 263.5 ± 106.4 µm. The mean time to nadir was 7.9 ± 6.3 months. The average RNFL and ganglion cell complex (GCC) thickness at the nadir were 92.6 ± 14.5 µm (47% showed thinning) and 77.9 ± 27.8 µm (70% showed thinning), respectively. The Frisén disc edema stage and average RNFL thickness at baseline correlated with a longer time to nadir, (r = 0.28 P = 0.003 and r = 0.24, P = 0.012, respectively). The nadir average RNFL thickness and the nadir average GCC thickness (r = 0.32, P = 0.001, r = 0.29, P = 0.002, respectively) correlated with the baseline visual field mean deviation. The final anatomical outcome of IIH episodes in this study resulted in RNFL and GCC thinning. The time to RNFL nadir and its values correlated with IIH severity at presentation.


Assuntos
Pseudotumor Cerebral , Tomografia de Coerência Óptica , Humanos , Pseudotumor Cerebral/diagnóstico por imagem , Estudos Retrospectivos , Retina , Atrofia
13.
Opt Lett ; 49(8): 2121-2124, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38621091

RESUMO

The purpose of this study is to verify the effect of anisotropic property of retinal biomechanics on vasodilation measurement. A custom-built optical coherence tomography (OCT) was used for time-lapse imaging of flicker stimulation-evoked vessel lumen changes in mouse retinas. A comparative analysis revealed significantly larger (18.21%) lumen dilation in the axial direction compared to the lateral (10.77%) direction. The axial lumen dilation predominantly resulted from the top vessel wall movement toward the vitreous direction, whereas the bottom vessel wall remained stable. This observation indicates that the traditional vasodilation measurement in the lateral direction may result in an underestimated value.


Assuntos
Tomografia de Coerência Óptica , Vasodilatação , Animais , Camundongos , Vasodilatação/fisiologia , Tomografia de Coerência Óptica/métodos , Estimulação Luminosa/métodos , Retina/diagnóstico por imagem , Retina/fisiologia , Vasos Retinianos/diagnóstico por imagem , Vasos Retinianos/fisiologia
14.
Opt Lett ; 49(8): 1880-1883, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38621029

RESUMO

Hyperreflective foci (HRFs) appear in optical coherence tomography (OCT) images of the retina and vitreous of patients with various ocular diseases. HRFs are hypothesized to be immune cells that appear in response to ischemia or tissue damage. To accurately identify HRFs and establish their clinical significance, it is necessary to replicate the detection of similar patterns in vivo in a small animal model. We combined visible-light OCT with temporal speckle averaging (TSA) to visualize and track vitreal HRFs (VHRFs) densities for three days after an optic nerve crush (ONC) injury. Resulting vis-OCT images revealed that VHRF density significantly increased approximately 10-fold at 12 h after ONC and returned to baseline three days after ONC. Additional immunohistochemistry results confirmed these VHRFs as inflammatory cells induced from optic nerve damage.


Assuntos
Traumatismos do Nervo Óptico , Tomografia de Coerência Óptica , Humanos , Camundongos , Animais , Tomografia de Coerência Óptica/métodos , Retina/diagnóstico por imagem , Traumatismos do Nervo Óptico/diagnóstico por imagem , Nervo Óptico/diagnóstico por imagem
15.
Opt Express ; 32(7): 11934-11951, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571030

RESUMO

Optical coherence tomography (OCT) can resolve biological three-dimensional tissue structures, but it is inevitably plagued by speckle noise that degrades image quality and obscures biological structure. Recently unsupervised deep learning methods are becoming more popular in OCT despeckling but they still have to use unpaired noisy-clean images or paired noisy-noisy images. To address the above problem, we propose what we believe to be a novel unsupervised deep learning method for OCT despeckling, termed Double-free Net, which eliminates the need for ground truth data and repeated scanning by sub-sampling noisy images and synthesizing noisier images. In comparison to existing unsupervised methods, Double-free Net obtains superior denoising performance when trained on datasets comprising retinal and human tissue images without clean images. The efficacy of Double-free Net in denoising holds significant promise for diagnostic applications in retinal pathologies and enhances the accuracy of retinal layer segmentation. Results demonstrate that Double-free Net outperforms state-of-the-art methods and exhibits strong convenience and adaptability across different OCT images.


Assuntos
Algoritmos , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Retina/diagnóstico por imagem , Cintilografia , Processamento de Imagem Assistida por Computador/métodos
16.
Vasc Health Risk Manag ; 20: 141-155, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38567028

RESUMO

Background and Aim: An elevated triglyceride-glucose (TyG) level is associated with increased risk of mortality in patients with CAD. Trimethylamine N-oxide (TMAO) has mechanistic links to atherosclerotic coronary artery disease (CAD) pathogenesis and is correlated with adverse outcomes. However, the incremental prognostic value of TMAO and TyG in the cohort of optical coherence tomography (OCT)-defined high-risk ST-segment elevation myocardial infarction (STEMI) patients is unknown. Methods: We studied 274 consecutive aged ≥18 years patients with evidence of STEMI and detected on pre-intervention OCT imaging of culprit lesions between March 2017 and March 2019. Outcomes: There were 22 (22.68%), 27 (27.84%), 26 (26.80%), and 22 (22.68%) patients in groups A-D, respectively. The baseline characteristics according to the level of TMAO and TyG showed that patients with higher level in both indicators were more likely to have higher triglycerides (p < 0.001), fasting glucose (p < 0.001) and higher incidence of diabetes (p = 0.008). The group with TMAO > median and TyG ≤ median was associated with higher rates of MACEs significantly (p = 0.009) in fully adjusted analyses. During a median follow-up of 2.027 years, 20 (20.6%) patients experienced MACEs. To evaluate the diagnostic value of the TyG index combined with TMAO, the area under the receiver operating characteristic curve for predicting MACEs after full adjustment was 0.815 (95% confidence interval, 0.723-0.887; sensitivity, 85.00%; specificity, 72.73%; cut-off level, 0.577). Among the group of patients with TMAO > median and TyG ≤ median, there was a significantly higher incidence of MACEs (p=0.033). A similar tendency was found in the cohort with hyperlipidemia (p=0.016) and diabetes mellitus (p=0.036). Conclusion: This study demonstrated the usefulness of combined measures of the TyG index and TMAO in enhancing risk stratification in STEMI patients with OCT-defined high-risk plaque characteristics. Trial Registration: This study was registered at ClinicalTrials.gov as NCT03593928.


Assuntos
Doença da Artéria Coronariana , Diabetes Mellitus , Metilaminas , Placa Aterosclerótica , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Adolescente , Adulto , Tomografia de Coerência Óptica/efeitos adversos , Glucose , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Triglicerídeos , Biomarcadores , Fatores de Risco , Placa Aterosclerótica/complicações , Doença da Artéria Coronariana/epidemiologia , Diabetes Mellitus/diagnóstico , Glicemia , Medição de Risco , Sistema de Registros
17.
Appl Opt ; 63(10): 2694-2703, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38568554

RESUMO

Accurate assessment of corneal curvatures using frequency domain optical coherence tomography (OCT) with galvanometer scanners remains challenging due to the well-known scan field distortion. This paper presents an algorithm and software for correcting the distortion using only two simple measurements in which a readily available standard sphere is positioned in different depths in front of the OCT scanner. This offers a highly accessible and easily reproducible method for the field distortion correction (FDC). The correction was validated by measuring different spherical phantoms and conducting corneal curvature measurements of ex vivo porcine corneas using a commercial spectral-domain OCT system and a clinically approved swept-source OCT as a reference instrument. Thus, the error in radius measurements of spherical phantoms was reduced by >90% and astigmatism by >80% using FDC. In explanted porcine eyes, the error in astigmatism measurements with the Telesto was reduced by 75% for power and 70% for angle. The best fitting sphere radius was determined up to a deviation of 0.4% from the Anterion. This paper describes a correction algorithm for OCT immanent distortion that is applicable to any scanning OCT setup and enables precise corneal curvature measurements. The MATLAB software for the FDC is publicly available on GitHub.


Assuntos
Astigmatismo , Tomografia de Coerência Óptica , Animais , Suínos , Algoritmos , Software , Córnea/diagnóstico por imagem
18.
Appl Opt ; 63(9): 2279-2285, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38568583

RESUMO

The stratum corneum of the outermost skin is an important barrier impeding transdermal permeation, and permeation enhancers can reduce the barrier resistance of the stratum corneum and enhance the permeation of drugs in tissues. The optical imaging depth, signal intensity, and scattering coefficient variation rules of skin tissues in time dimension are obtained by using optical coherence tomography (OCT). The effect of optical clearing agents (OCAs) on OCT imaging is obtained by quantitatively analyzing the changes in the optical properties of tissues. D-fructose, one of the monosaccharides, and sucrose, one of the disaccharides, were selected for the ex vivo optical clearing experiments on pig skin tissues utilizing the dimethyl sulfoxide (DMSO) carrier effect. We find that DMSO synergized with sugars applied to skin tissue has a more significant increase in the optical imaging depth and signal intensity, and a reduction in the scattering coefficient with an increasing concentration of DMSO. DMSO with a high concentration and D-fructose with saturated concentration (10:1; v/v) effectively reduce light attenuation in OCT imaging and improve the image quality. This operation will also shorten the application time to minimize skin damage from hyperosmotic agents.


Assuntos
Açúcares , Tomografia de Coerência Óptica , Animais , Suínos , Dimetil Sulfóxido/farmacologia , Pele , Frutose
19.
Skin Res Technol ; 30(4): e13684, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38558475

RESUMO

BACKGROUND: Hydradermabrasion, also known as "HydraFacial," is an exfoliative cosmetic procedure for skin rejuvenation that has gained popularity. Despite its increasing popularity, clinical studies validating its efficacy with non-invasive assessment of histological changes to the skin, are scarce. In this study, we used Line-Field Confocal Optical Coherence Tomography (LC-OCT), an optical imaging device, to non-invasively visualize microscopic changes to skin anatomy after hydradermabrasion treatment. MATERIALS/METHODS: Eight volunteers (Fitzpatrick skin types II-V) were recruited for this study. Images, using LC-OCT (DeepLive, DAMAE medical) were obtained before and after hydradermabrasion and at 2 weeks post-treatment. A commercially available hydradermabrasion device was utilized to perform the dermabrasion. RESULTS: In the epidermis, initially, a decrease in the average thickness of the stratum corneum, from 9.42 to 6.67 µm was visualized in LC-OCT images after hydradermabrasion. However, at 2 weeks of follow-up, the average stratum corneum thickness was 9.75 µm, resulting in an overall increase in the average thickness after treatment. Improved homogenization of the stratum corneum and decreased number of undulations in the epidermis post-treatment were also visualized. In all the subjects, the superficial dermis appeared stretched, which returned to baseline by the 2-week follow-up. At the 2-week follow-up, there were no visible differences in the quality and quantity of collagen fibers in the dermis. CONCLUSION: In our study, LC-OCT images of the epidermis and dermis demonstrated microscopic features of skin rejuvenation when treated with hydradermabrasion. Thus, not only highlighting the efficacy of hydradermabrasion but also the potential of LC-OCT to serve as a tool for visualizing the microscopic effects of cosmetic procedures on skin anatomy.


Assuntos
Pele , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Pele/diagnóstico por imagem , Pele/anatomia & histologia , Epiderme/diagnóstico por imagem , Epiderme/anatomia & histologia
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