Advances In Optical Coherence Tomography Research Articles

Advances in Optical Coherence Tomography and Confocal Laser Endomicroscopy in Pulmonary Diseases

Diagnosing and monitoring pulmonary diseases is highly dependent on imaging, physiological function tests and tissue sampling. Optical coherence tomography (OCT) and confocal laser endomicroscopy (CLE) are novel imaging techniques with near-microscopic resolution that can be easily and safely combined with conventional bronchoscopy. Disease-related pulmonary anatomical compartments can be visualized, real time, using these techniques. In obstructive lung diseases, airway wall layers and related structural remodelling can be identified and quantified. In malignant lung disease, normal and malignant areas of the central airways, lung parenchyma, lymph nodes and pleura can be discriminated. A growing number of interstitial lung diseases (ILDs) have been visualized using OCT or CLE. Several ILD-associated structural changes can be imaged: fibrosis, cellular infiltration, bronchi(ol)ectasis, cysts and microscopic honeycombing. Although not yet implemented in clinical practice, OCT and CLE have the potential to improve detection and monitoring pulmonary diseases and can contribute in unravelling the pathophysiology of disease and mechanism of action of novel treatments. Indeed, assessment of the airway wall layers with OCT might be helpful when evaluating treatments targeting airway remodelling. By visualizing individual malignant cells, CLE has the potential as a real-time lung cancer detection tool. In the future, both techniques could be combined with laser-enhanced fluorescent-labelled tracer detection. This review discusses the value of OCT and CLE in pulmonary medicine by summarizing the current evidence and elaborating on future perspectives.

Association between early-stage chronic kidney disease and reduced choroidal thickness in essential hypertensive patients.

The introduction in the past few years of advanced optical coherence tomography (OCT) techniques has greatly increased our understanding of the choroid, which is the most important vascular layer of the eye. Our study aimed to assess choroidal thickness by using swept-source OCT (SS-OCT) in essential hypertensive patients (EHs) with and without early-stage chronic kidney disease (CKD). We enrolled 100 EHs, of whom 65 were without kidney damage, and 35 had stage 1-3 CKD. In all of the participants, SS-OCT and a routine biochemical workup were performed. Glomerular filtration rate (GFR) was estimated by the CKD Epidemiology Collaboration equation (eGFR). CKD was defined in agreement with the Kidney Disease Outcomes Quality Initiative Kidney Disease: Improving Global Outcomes 2002 guidelines. OCT measurements were performed according to the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, which divides the macula into nine subfields. The circular grid consists of three concentric rings. EHs with CKD showed thinner choroidal thicknesses than those without it (all p < 0.05), even after adjustment for potential confounding factors. Overall choroidal thickness correlated significantly and directly with eGFR (r = 0.36) and negatively with urinary albumin excretion (r = -0.39). The association of choroidal thickness with CKD was confirmed in multiple logistic regression analyses once the effects of age and other confounding variables were accounted for. The odds ratio of having early-stage CKD associated with a standard deviation increase in overall choroidal thickness was 0.43 (0.24-0.75, 95% confidence interval; p = 0.007). In conclusion, our study confirms the close relationships between changes in ocular microcirculation and renal dysfunction.

The impact of disc hemorrhage studies on our understanding of glaucoma: a systematic review 50 years after the rediscovery of disc hemorrhage.

To trace the influence of disc hemorrhage studies on our understanding of glaucoma. Major articles published during the last 50 years since the rediscovery of disc hemorrhage were identified. A total of 196 articles were selected from 435 articles retrieved using the keywords glaucoma and disc hemorrhage as of August 9 2018 from PubMed. The main characteristics of disc hemorrhage, including its morphology, recurrence rate, duration, increased incidence in glaucoma, and role in the progression of normal tension glaucoma was well understood by the year 2000. Since then, studies have focused on more sophisticated and accurate methods of elucidating both structural and functional progression, with special attention to the role of the lamina cribrosa. Nevertheless, both the mechanism of disc hemorrhage development and its fuller relationship with glaucoma remain unclear. Disc hemorrhage research requires careful study of glaucomatous optic neuropathy. This has been facilitated by recent advances in optical coherence tomography (OCT) angiography and other OCT technologies. Furthermore, animal studies of disc hemorrhage promise new insights into glaucomatous optic neuropathy.

Development of an Advanced Optical Coherence Tomography System for Radiation Dosimetry

Introduction: According to the literature, optical coherence tomography (OCT) can be used measure radiation absorbed dose. This study was carried out to design a computed tomography system for the calculation of absorbed dose and optimization of dose delivery in radiotherapy using gel dosimeters. Material and Methods: An advanced charge-coupled device based OCT system was developed in laboratory with the capability for high resolution three-dimensional (3D) radiation dosimetry using gel dosimeters. The OCT system was compared to magnetic resonance imaging (MRI) as a standard system to investigate its accuracy. Additionally, a number of parameters were checked for assessing the performance of the system. Results: Developing an advanced OCT system, the calibration curve was drawn for OCT and MRI and the received dose values were compared. The amounts of dose obtained from OCT and MRI were 1.98 and 2 Gy respectively with a relative difference of 2%. Conclusion: The quality of treatment can be improved using OCT system in radiotherapy dosimetry.

VLE for Identification of Subsquamous T1a Esophageal Adenocarcinoma

Barrett's Esophagus (BE) is detected using White Light Endoscopy (WLE) or narrow band imaging (NBI) during esophagogastroduodenoscopy (EGD). Subsquamous disease is often not visualized using traditional WLE or NBI, presenting a challenge when surveying and treating patients with BE. Newer technologies, such as volumetric laser endomicroscopy (VLE), allow for visualization of abnormalities perhaps not identified by traditional endoscopic imaging modalities. Herein, we present a case of subsquamous adenocarcinoma of the esophagus successfully identified using the NvisionVLE® Imaging System allowing for targeted, curative endoscopic mucosal resection (EMR). A 68-year-old male with history of short segment BE and T1a adenocarcinoma 1cm from the gastroesophageal junction status post successful EMR followed by radiofrequency ablation (RFA) was found to have subsequent surveillance biopsies showing intramucosal cancer (IMC) despite no residual mucosal abnormalities, triggering referral to a tertiary care center. EGD was performed and WLE, NBI, and the NvisionVLE® Imaging System initially revealed no significant abnormalities, including no obvious residual BE. However, upon reviewing VLE data prior to subsequent surveillance endoscopy, subsquamous regions of suspicion were identified approximately 1cm proximal to the original BE segment. EGD was performed and the area identified on review of VLE data showed slight discoloration of the mucosa using NBI. Cautery marks were placed on both sides as landmarks and VLE was then performed re-confirming the suspicious abnormal subsquamous glandular structures and relation of cautery marks. VLE-targeted EMR was performed. Pathology confirmed subsquamous T1 adenocarcinoma with negative margins. Surveillance biopsies from within the prior BE segment length were negative for BE, dysplasia, or cancer. Patients with adenocarcinoma or dysplasia on random biopsies, with no suspicious lesion under WLE or NBI can present a challenge. However, with use of the NvisionVLE® Imaging System, subsquamous abnormalities can be identified as shown in our patient. The precise localization allows for complete and curative therapy, unachievable by older technologies. More research is needed to prove the broader impact of Advanced Optical Coherence Tomography in the management of BE related dysplasia and cancer, however, the results in our patient show its potential impact on BE patients, especially with subsquamous disease.1760_A Figure 1. VLE imaging showing subsquamous areas of suspicion1760_B Figure 2. EGD image with cautery marks outlining area identified on VLE1760_C Figure 3. Pathology slides confirming subsquamous T1a adenocarcinoma

Wide-Field Functional Microscopy of Peripheral Nerve Injury and Regeneration

Severe peripheral nerve injuries often result in partial repair and lifelong disabilities in patients. New surgical techniques and better graft tissues are being studied to accelerate regeneration and improve functional recovery. Currently, limited tools are available to provide in vivo monitoring of changes in nerve physiology such as myelination and vascularization, and this has impeded the development of new therapeutic options. We have developed a wide-field and label-free functional microscopy platform based on angiographic and vectorial birefringence methods in optical coherence tomography (OCT). By incorporating the directionality of the birefringence, which was neglected in the previously reported polarization-sensitive OCT techniques for nerve imaging, vectorial birefringence contrast reveals internal nerve microanatomy and allows for quantification of local myelination with superior sensitivity. Advanced OCT angiography is applied in parallel to image the three-dimensional vascular networks within the nerve over wide-fields. Furthermore, by combining vectorial birefringence and angiography, intraneural vessels can be discriminated from those of the surrounding tissues. The technique is used to provide longitudinal imaging of myelination and revascularization in the rodent sciatic nerve model, i.e. imaged at certain sequential time-points during regeneration. The animals were exposed to either crush or transection injuries, and in the case of transection, were repaired using an autologous nerve graft or acellular nerve allograft. Such label-free functional imaging by the platform can provide new insights into the mechanisms that limit regeneration and functional recovery, and may ultimately provide intraoperative assessment in human subjects.

Advanced Optical Coherence Tomography Angiography Analysis of Age-related Macular Degeneration Complicated by Onset of Unilateral Choroidal Neovascularization

To analyze optical coherence tomography angiography (OCTA) quantitative features in patients affected by new-onset choroidal neovascularization (CNV) in 1 eye and early/intermediate age-related macular degeneration (AMD) in the fellow eye. Case-control study. Setting: Clinical practice. Thirty patients and 30 age-matched controls. Both cohorts underwent complete ophthalmologic examination, including best-corrected visual acuity (BCVA) measurement, biomicroscopy, fluorescein angiography (FA) and indocyanine green angiography (ICGA) examination, optical coherence tomography, and OCTA scans. The 1-way a test with Bonferroni correction was used to assess statistical significance and Tau Kendall's correlation analysis was performed. BCVA, choroidal thickness, vessel density, vessel tortuosity, vessel dispersion. and vessel rarefaction. Mean BCVA was 20/32 for CNV eyes and 20/20 for both fellow and control eyes. Choroidal thickness was 190.33 ± 63.98μm for CNV eyes, 216.83 ± 50.31μm for fellow eyes, and 310.52 ± 27.13μm for controls. The quantitative analysis of retinal vessels revealed significant alterations, especially in the deep capillary plexus and radial peripapillary capillaries, both in CNV and in fellow eyes, compared with controls. In particular, decreased vessel density and tortuosity and increased dispersion and rarefaction were found. Several significant correlations were also found among the quantitative parameters adopted. New postprocessing OCTA parameters are able to detect deep retinal vascular alterations quantitatively, in both CNV-affected and fellow eyes of patients with new-onset CNV. Further investigations are warranted in order to explore the validity of these new approaches on follow-up.

Utility of optical coherence tomography in the evaluation of sellar and parasellar mass lesions.

Anterior visual pathway compression is a common feature of sellar region masses. We review the visual pathway neuroanatomy pertaining to sellar and parasellar lesions and describe recent advances in optical coherence tomography (OCT) imaging that have provided a novel quantitative perspective in the evaluation and management of such patients. Ultrastructural measurements of optic nerve integrity using OCT, namely peripapillary retinal nerve fiber layer (pRNFL) and the ganglion cell and inner plexiform layer (GCIPL) thicknesses, have been shown to correlate with visual acuity and visual field deficits on perimetry in patients with compressive sellar region masses. In some cases, OCT can visualize early signs of anterior visual pathway involvement in the absence of clinically evident visual field loss or optic disc pallor. OCT is particularly useful when assessing patients who demonstrate less reliable visual field testing. Furthermore, there is growing awareness that pRNFL and GCIPL thinning preoperatively correlate with worse visual recovery following chiasmal decompression, highlighting the prognostic utility of OCT in this patient population. OCT provides a complimentary, yet critical, role in quantitatively assessing ultrastructural retinal injury in patients with sellar and parasellar lesions compressing the anterior visual pathway and should be incorporated into routine evaluation.

Swept-Source Optical Coherence Tomography-Supervised Biopsy.

Currently, only skin biopsy can provide definitive histological confirmation for the diagnosis of skin diseases. To improve the diagnostic accuracy and to assist the dermatologist, various imaging techniques have been added to the examination of skin. Among all these techniques, the recent advances in optical coherence tomography (OCT) have made it possible to image the skin up to 2 millimeters in depth. To testify the feasibility of OCT imaging in skin biopsy, the authors investigated the OCT imaging for real-time visualization of needle insertion and punch biopsy techniques in both a tissue phantom and biological tissue. A swept-source OCT with 1,305-nm central wavelength was used in this study. The euthanized mouse was used for real-time visualization of needle insertion. A gelatin phantom with India ink was used to demonstrate the punch biopsy using OCT. Optical coherence tomography can provide guidance for skin injections as well as real-time imaging to assist in the performance of punch biopsy. Optical coherence tomography holds potential not only as a diagnostic tool in dermatology. It can also allow for visualization for more accurate drug delivery, and noninvasively assess the response to treatment.

Sa1924 IMAGE VISUALIZATION ENHANCEMENT IDENTIFIES ADDITIONAL AREAS SUSPICIOUS FOR DYSPLASIA ON VOLUMETRIC LASER ENDOMICROSCOPY

Volumetric laser endomicroscopy (VLE) uses advanced optical coherence tomography for real-time, cross-sectional imaging to a depth of 3 mm and a resolution of 7 microns. The VLE probe, deployed through the endoscope’s working channel, scans 6 cm of esophagus in 90 seconds. While prior studies have demonstrated high sensitivity for VLE detection of dysplasia within Barrett’s esophagus (BE), there are cases where random tissue sampling confirms dysplastic BE despite an absence of concerning VLE findings. Our aim was to assess whether new software with Image Visualization Enhancement (IVE), which uses color to highlight specific VLE features including hyporeflective structures and loss of normal wall layering, can identify areas of concern missed on initial VLE review. A multicenter US registry prospectively collected data on 1000 patients at 18 sites when VLE was used for esophageal evaluation. All procedures used the NvisionVLE® Imaging System (NinePoint Medical, Bedford, MA), and all sites obtained Institutional Review Board approval prior to beginning enrollment. Data review identified patients found to have BE at least indefinite for dysplasia on any tissue sampling, after which all cases without a focally concerning VLE finding were selected (Fig 1). All VLE images for 16 of these cases were loaded onto a VLE console and presented to a gastroenterologist with expertise in BE assessment and VLE interpretation. Each case was reviewed as a standard VLE, after which IVE was turned on and a repeat evaluation was performed. Time to complete image review using each approach, as well as findings and an overall confidence rating for likelihood of dysplasia (1-5 scale) were documented. The mean review time for standard VLE was 4 minutes per scan (range 3-5). A mean of 2 (1-7) focal areas of concern for dysplasia were identified on each scan (Fig 2). Subsequent review with IVE required, on average, an additional 2 minutes (1-3); in every case, focal areas of concern on VLE corresponded to highlighted areas on IVE. In half of the cases (8/16), use of IVE identified at least one additional suspicious region not selected by the reviewer during standard VLE image review. The mean confidence level for dysplasia was 2.8 (1-5), indicating a moderate degree of certainty. While focal areas suspicious for dysplasia were found in all scans deemed not concerning by the original endoscopist, using IVE with standard VLE identified additional focal abnormalities in half of the cases with a moderate level of confidence that dysplasia was located. Incorporating IVE into the VLE procedure added only a few minutes of time to each study. These preliminary data suggest that VLE with IVE will further enhance an endoscopist’s ability to identify dysplastic disease without missing a focal lesion, especially for early VLE users.Figure 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Extracting Blood Vessels From Full-Field OCT Data of Human Skin by Short-Time RPCA

Recent advances in optical coherence tomography (OCT) lead to the development of OCT angiography to provide additional helpful information for diagnosis of diseases like basal cell carcinoma. In this paper, we investigate how to extract blood vessels of human skin from full-field OCT (FF-OCT) data using the robust principal component analysis (RPCA) technique. Specifically, we propose a short-time RPCA method that divides the FF-OCT data into segments and decomposes each segment into a low-rank structure representing the relatively static tissues of human skin and a sparse matrix representing the blood vessels. The method mitigates the problem associated with the slow-varying background and is free of the detection error that RPCA may have when dealing with FF-OCT data. Both short-time RPCA and RPCA methods can extract blood vessels from FF-OCT data with heavy speckle noise, but the former takes only half the computation time of the latter. We evaluate the performance of the proposed method by comparing the extracted blood vessels with the ground truth vessels labeled by a dermatologist and show that the proposed method works equally well for FF-OCT volumes of different quality. The average F-measure improvements over the correlation-mapping OCT method, the modified amplitude-decorrelation OCT angiography method, and the RPCA method, respectively, are 0.1835, 0.1032, and 0.0458.

Advances in optical coherence tomography in dermatology-a review.

Optical coherence tomography (OCT) was introduced as an imaging system, but like ultrasonography, other measures, such as blood perfusion and polarization of light, have enabled the technology to approach clinical utility. This review aims at providing an overview of the advances in clinical research based on the improving technical aspects. OCT provides cross-sectional and en face images down to skin depths of 0.4 to 2.00mm with optical resolution of 3 to 15 μm. Dynamic optical coherence tomography (D-OCT) enables the visualization of cutaneous microvasculature via detection of rapid changes in the interferometric signal of blood flow. Nonmelanoma skin cancer (NMSC) is the most comprehensively investigated topic, resulting in improved descriptions of morphological features and diagnostic criteria. A refined scoring system for diagnosing NMSC, taking findings from conventional and D-OCT into account, is warranted. OCT diagnosis of melanoma is hampered by the resolution and the optical properties of melanin. D-OCT may be of value in diseases characterized with dynamic changes in the vasculature of the skin and the addition of functional measures is strongly encouraged. In conclusion, OCT in dermatology is still an emerging technology that has great potential for improving further in the future.

Optical coherence tomography angiography monitors human cutaneous wound healing over time.

In vivo imaging of the complex cascade of events known to be pivotal elements in the healing of cutaneous wounds is a difficult but essential task. Current techniques are highly invasive, or lack the level of vascular and structural detail required for accurate evaluation, monitoring and treatment. We aimed to use an advanced optical coherence tomography (OCT)-based angiography (OCTA) technique for the non-invasive, high resolution imaging of cutaneous wound healing. We used a clinical prototype OCTA to image, identify and track key vascular and structural adaptations known to occur throughout the healing process. Specific vascular parameters, such as diameter and density, were measured to aid our interpretations under a spatiotemporal framework. We identified multiple distinct, yet overlapping stages, hemostasis, inflammation, proliferation, and remodeling, and demonstrated the detailed vascularization and anatomical attributes underlying the multifactorial processes of dermatologic wound healing. OCTA provides an opportunity to both qualitatively and quantitatively assess the vascular response to acute cutaneous damage and in the future, may help to ascertain wound severity and possible healing outcomes; thus, enabling more effective treatment options.

Optical coherence tomography angiography of normal skin and inflammatory dermatologic conditions.

In clinical dermatology, the identification of subsurface vascular and structural features known to be associated with numerous cutaneous pathologies remains challenging without the use of invasive diagnostic tools. To present an advanced optical coherence tomography angiography (OCTA) method to directly visualize capillary-level vascular and structural features within skin in vivo. An advanced OCTA system with a 1310 nm wavelength was used to image the microvascular and structural features of various skin conditions. Subjects were enrolled and OCTA imaging was performed with a field of view of approximately 10 × 10 mm. Skin blood flow was identified using an optical microangiography (OMAG) algorithm. Depth-resolved microvascular networks and structural features were derived from segmented volume scans, representing tissue slabs of 0-132, 132-330, and 330-924 μm, measured from the surface of the skin. Subjects with both healthy and pathological conditions, such as benign skin lesions, psoriasis, chronic graft-versus-host-disease (cGvHD), and scleroderma, were OCTA scanned. Our OCTA results detailed variations in vascularization and local anatomical characteristics, for example, depth-dependent vascular, and structural alterations in psoriatic skin, alongside their resolve over time; vascular density changes and distribution irregularities, together with corresponding structural depositions in the skin of cGvHD patients; and vascular abnormalities in the nail folds of a patient with scleroderma. OCTA can image capillary blood flow and structural features within skin in vivo, which has the potential to provide new insights into the pathophysiology, as well as dynamic changes of skin diseases, valuable for diagnoses, and non-invasive monitoring of disease progression and treatment. Lasers Surg. Med. 50:183-193, 2018. © 2018 Wiley Periodicals, Inc.

A Quantum Field Approach for Advancing Optical Coherence Tomography Part I: First Order Correlations, Single Photon Interference, and Quantum Noise.

Optical coherence tomography has become an important imaging technology in cardiology and ophthalmology, with other applications under investigations. Major advances in optical coherence tomography (OCT) imaging are likely to occur through a quantum field approach to the technology. In this paper, which is the first part in a series on the topic, the quantum basis of OCT first order correlations is expressed in terms of full field quantization. Specifically first order correlations are treated as the linear sum of single photon interferences along indistinguishable paths. Photons and the electromagnetic (EM) field are described in terms of quantum harmonic oscillators. While the author feels the study of quantum second order correlations will lead to greater paradigm shifts in the field, addressed in part II, advances from the study of quantum first order correlations are given. In particular, ranging errors are discussed (with remedies) from vacuum fluctuations through the detector port, photon counting errors, and position probability amplitude uncertainty. In addition, the principles of quantum field theory and first order correlations are needed for studying second order correlations in part II.

The use of optical coherence tomography in neuro-ophthalmology

In the last decade, with the advances of optical coherence tomography (OCT) technology, different imaging protocols and analysis algorithms have been introduced to maximize the potential of this diagnostic tool in the evaluation of different eye diseases. This review aims to provide an update on these additional features, with respect to the management of a diverse range of neuro-ophthalmologic conditions. Macular ganglion cell complex (mGCC) analysis has been shown to be superior to peripapillary retinal nerve fiber layer (pRNFL) analysis in certain settings, such as differentiating Leber's hereditary optic neuropathy from functional visual loss; monitoring neurodegenerative diseases or multiple sclerosis; and predicting visual loss in nonarteritic ischemic optic neuropathy. mGCC analysis also demonstrates high correlation with perimetry and might serve as an early structural indicator of irreversible neuronal loss. Compared to pRNFL, retinal thickness analysis of the optic nerve head demonstrates better correlation with the severity of papilledema, thus enabling its possible application in detecting raised intracranial pressure, especially in the pediatric group. Upcoming research on emerging OCT technologies including OCT-angiography, enhanced depth imaging, retinal single-layer analysis and portable systems will hopefully further enhance the utility of OCT in the field. It is crucial for neuro-ophthalmologists to be updated and familiar with these newer OCT imaging protocols and to make appropriate choices for different clinical scenarios, in order to optimize the diagnostic sensitivity and specificity.

Estimating Human Trabecular Meshwork Stiffness by Numerical Modeling and Advanced OCT Imaging.

PurposeThe purpose of this study was to estimate human trabecular meshwork (hTM) stiffness, thought to be elevated in glaucoma, using a novel indirect approach, and to compare results with direct en face atomic force microscopy (AFM) measurements.MethodsPostmortem human eyes were perfused to measure outflow facility and identify high- and low-flow regions (HF, LF) by tracer. Optical coherence tomography (OCT) images were obtained as Schlemm's canal luminal pressure was directly manipulated. TM stiffness was deduced by an inverse finite element modeling (FEM) approach. A series of AFM forcemaps was acquired along a line traversing the anterior angle on a radially cut flat-mount corneoscleral wedge with TM facing upward.ResultsThe elastic modulus of normal hTM estimated by inverse FEM was 70 ± 20 kPa (mean ± SD), whereas glaucomatous hTM was slightly stiffer (98 ± 19 kPa). This trend was consistent with TM stiffnesses measured by AFM: normal hTM stiffness = 1.37 ± 0.56 kPa, which was lower than glaucomatous hTM stiffness (2.75 ± 1.19 kPa). None of these differences were statistically significant. TM in HF wedges was softer than that in LF wedges for both normal and glaucomatous eyes based on the inverse FEM approach but not by AFM. Outflow facility was significantly correlated with TM stiffness estimated by FEM in six human eyes (P = 0.018).ConclusionsTM stiffness is higher, but only modestly so, in glaucomatous patients. Outflow facility in both normal and glaucomatous human eyes appears to associate with TM stiffness. This evidence motivates further studies to investigate factors underlying TM biomechanical property regulation.

What pediatric ophthalmologists need to know about octs: pearls and pitfalls for clinical care

As Optical Coherence Tomography (OCT) technology has advanced, it has increased availability and utility in pediatric practices. As the technology becomes an integral part of clinical care, it is critical for pediatric ophthalmologists to understand how to incorporate OCT into their clinical flow, interpret results, and make clinical decisions based on OCT findings. Our panel is composed of one of the coinventors of OCT (David Huang, MD) as well as innovators of OCT imaging of the anterior segment. The purpose of this workshop is to provide fundamental information about OCT interpretation and describe recent advances in OCT. With this basic information, we will be able to explore pearls and pitfalls in utilizing OCT for anterior segment, pediatric glaucoma management, and retinal pathology.

OCT angiography and visible-light OCT in diabetic retinopathy

In recent years, advances in optical coherence tomography (OCT) techniques have increased our understanding of diabetic retinopathy, an important microvascular complication of diabetes. OCT angiography is a non-invasive method that visualizes the retinal vasculature by detecting motion contrast from flowing blood. Visible-light OCT shows promise as a novel technique for quantifying retinal hypoxia by measuring the retinal oxygen delivery and metabolic rates. In this article, we discuss recent insights provided by these techniques into the vascular pathophysiology of diabetic retinopathy. The next milestones for these modalities are large multicenter studies to establish consensus on the most reliable and consistent outcome parameters to study diabetic retinopathy.

Regarding ‘Advances of optical coherence tomography in myopia and pathologic myopia’

Regarding ‘Advances of optical coherence tomography in myopia and pathologic myopia’