Intraoperative imaging can affect decision making and outcomes in neurovascular surgery. Current modalities have limitations...
Relative to other specialties, ophthalmologists deal infrequently with uncertainty. Of course, every patient requires advice, which in turns requires a weighing of risks and benefits, and some pondering of potential unknowns. But unlike internists, ophthalmologists often see the pathology directly. And what once was hidden from us is now rapidly being revealed with new technologies like optical coherence tomography and adaptive optics. Within the ophthalmic kingdom, however, some subspecialties deal with more uncertainty than others. Specialists in uveitis, in particular, often confront uncertainty. Is the pathology autoimmune or infectious? Or even possibly a malignancy like lymphoma? And nothing confounds a ...
A 41-year-old woman with skew deviation had cyclotorsion of both eyes. This resulted in a falsely low probability plot of retinal nerve fiber layer thickness in adjacent clock hours on optical coherence tomography (OCT) due to displacement of the retinal nerve fiber layer peaks. Ocular cyclotorsion may cause misinterpretation of OCT probability plots. OCT retinal nerve fiber layer plots also may be used to objectively quantify the degree of ocular cyclotorsion.
Optic neuritis is an inflammatory optic neuropathy that affects many patients with multiple sclerosis (MS) at some point during their disease course. Differentiation of acute episodes of MS-associated optic neuritis from other autoimmune and inflammatory optic neuropathies is vital for treatment choice and further patient management, but is not always straightforward. Over the past decade, a number of new imaging, laboratory and electrophysiological techniques have entered the clinical arena. To date, however, no consensus guidelines have been devised to specify how and when these techniques can be most rationally applied for the diagnostic work-up of patients with acute optic neuritis ...
Background: The heterogeneity of the disease course in multiple sclerosis (MS) remains a challenge for patient management and clinical trials. Objective: The objective of this paper is to investigate the relationship between disease course heterogeneity and retinal layer thicknesses in MS. Methods: A total of 230 MS patients and 63 healthy control subjects were included. Spectral-domain OCT scanning of the peripapillary and macular regions was performed, followed by automated eight-layer segmentation. Generalised estimation equations were used for comparisons. Receiver operating characteristic (ROC) curves were calculated for distinguishing a benign from a typical disease course. Results: Primary progressive patients showed relative ...
UC Riverside Received a 2014 NIH Grant for $437,523 for Studying Optical Detection of the Pre-Seizure State. The principal investigator is Devin Binder. The program began in 2-012 and ends in 2016. Below is a summary of the proposed work. Reliable means of detecting changes which occur during the "pre-seizure state" could serve as a method of seizure prediction, a benchmark in epilepsy research (NIH Curing Epilepsy Conferences, 2000 and 2007). Our preliminary data indicate pre-seizure constriction in brain extracellular space (ECS) accompanied by reduction in near-infrared (NIR) optical scattering prior to detection of seizure by electroencephalography (EEG). The ...
Aim of work The aim of our work was to detect any structural or functional visual defects during and in between the attacks in patients with migraine. Patient and methods Sixty patients with migraine as well as sixty age and sex matched controls were included. All cases were subjected to full ophthalmological examination. Cases with any previously known optic nerve abnormalities or with history of increased intraocular pressure were excluded from this study. A full threshold 24-2 automated perimetry as well as optical coherence tomography (OCT) were performed for retinal nerve fiber layer (RNFL) thickness. Correlations between results of study ...
Background To assess the chorioretinal thickness changes using spectral-domain optical coherence tomography (SD-OCT) and to evaluate the association between these structural changes and cognitive impairment in Alzheimer's disease (AD). Design Prospective, cross-sectional study Participants 31 eyes of 31 consecutive patients with AD and 30 eyes of 30 cognitively healthy age-matched control subjects were recruited Methods SD-OCT (RTVue-100) was used to measure the macular ganglion cell complex thickness (mGCC), outer retinal thickness (ORL), and the choroidal thickness (CT). Cognitive function was evaluated by Mini-Mental State examination (MMSE) on the same day of the optical examination. Main Outcome Measures chorioretinal thickness ...
Optical Coherence Tomography (OCT) provides non-labeling, real-time and high resolution images, which has the potential to transform the paradigm of surgical guidance and preclinical animal studies. The design and development of OCT devices for neurosurgery guidance and novel imaging algorithms for monitoring anti-cancer therapy have been pursued in this work. A forward-imaging needle-type OCT probe was developed which can fit into minimally invasive tools (I.D. ~ 1mm), detect the at-risk blood vessels, and identify tissue micro-landmarks. This promising guidance tool improves the safety and the accuracy of needle-based procedures, which are currently performed without imaging feedback. Despite the great imaging ...
We established a strategy to perform cross-validation of serial optical coherence scanner imaging (SOCS) and diffusion tensor imaging (DTI) on a postmortem human medulla. Following DTI, the sample was serially scanned by SOCS, which integrates a vibratome slicer and a multi-contrast optical coherence tomography rig for large-scale three-dimensional imaging at microscopic resolution. The DTI dataset was registered to the SOCS space. An average correlation coefficient of 0.9 was found between the co-registered fiber maps constructed by fractional anisotropy and retardance contrasts. Pixelwise comparison of fiber orientations demonstrated good agreement between the DTI and SOCS measures. Details of the comparison ...
Background: Retinal optical coherence tomography (OCT) permits quantification of retinal layer atrophy relevant to assessment of neurodegeneration in multiple sclerosis (MS). Measurement artefacts may limit the use of OCT to MS research. Objective: An expert task force convened with the aim to provide guidance on the use of validated quality control (QC) criteria for the use of OCT in MS research and clinical trials. Methods: A prospective multi-centre ( n = 13) study. Peripapillary ring scan QC rating of an OCT training set ( n = 50) was followed by a test set ( n = 50). Inter-rater agreement was calculated using kappa statistics. Results were ...
Optical coherence tomography (OCT) of the macula has become increasingly important in the investigation of retinal pathology. However, deformable image registration, which is used for aligning subjects for pairwise comparisons, population averaging, and atlas label transfer, has not been well–developed and demonstrated on OCT images. In this paper, we present a deformable image registration approach designed specifically for macular OCT images. The approach begins with an initial translation to align the fovea of each subject, followed by a linear rescaling to align the top and bottom retinal boundaries. Finally, the layers within the retina are aligned by a deformable ...
By measuring retinal thinning, optical coherence tomography (OCT) provides an inexpensive and noninvasive means of assessing CNS pathology in people with MS. Two new studies show that OCT findings correlate with spinal cord and cortical MRI measures. Over the past 30 years, magnetic resonance imaging (MRI) has emerged as a primary tool for diagnosing multiple sclerosis (MS). More recently, a new kid on the block, optical coherence tomography (OCT), has been gaining recognition as a cheaper and less invasive means of assessing pathology in the central nervous system (CNS) of MS patients. In two presentations at the American Academy of ...
We investigated the feasibility of OCT in monitoring the viability of the brain. It was confirmed that after an overdose of pentobarbital sodium salt for an euthanasia, the OCT signal intensity increased before cardiac arrest and finally became 2.7 times, and by periodically changing the tissue temperature from 20 to 32 ℃ in vivo, average correlation coefficients between the ratio of signal intensity (RSI) and temperature were determined to be -0.42 to -0.50. RSI reversibly changed with subsequent variations of temperatures and finally increased rapidly just before cardiac arrest. These results indicate that RSI could correspond to decreases ...
We investigated the association of retinal nerve fibre layer thickness (RNFL) with white matter damage assessed by diffusion tensor imaging (DTI). Forty-four MS patients and 30 healthy subjects underwent optical coherence tomography. DTI was analysed with a voxel-based whole brain and region-based analysis of optic radiation, corpus callosum and further white matter. Correlations between RNFL, fractional anisotropy (FA) and other DTI-based parameters were assessed in patients and controls. RNFL correlated with optic radiation FA, but also with corpus callosum and remaining white matter FA. Our findings demonstrate that RNFL changes indicate white matter damage exceeding the visual pathway.
Retinal nerve fiber layer thickness (RNFL) measured by means of Optical Coherence Tomography (OCT) has been used as a marker not only of ophthalmologic diseases but also of neurodegenerative diseases such as Alzheimer’s disease (AD) and mild cognitive impairment (MCI). The purpose of this work was to demonstrate that patients with amnestic MCI show an intermediate RNFL thickness between normality and AD, and a macular volume and thickness as well. In a cross-sectional study we consecutively recruited 18 patients with AD, 21 with MCI, and 41 healthy controls. OCT was performed in all of them to measure circumpapillary RNFL ...
Multiple sclerosis (MS) is a disorder characterized by inflammation and neuroaxonal degeneration. The latter is held responsible for the irreversible disability in patients with MS. The eye is a unique window into the brain. With the advent of optical coherence tomography, accurate quantification of retinal layer thickness has become feasible. Neuroaxonal degeneration affecting the retinal layers is structurally and functionally related to pathology in the visual pathways, which is most severe following MS optic neuritis. This is relevant to recognize because MS optic neuritis may mask the subtle thinning of retinal layers associated with global CNS atrophy, which is also ...
Aims To investigate swept-source optical coherence tomography (OCT) angiography in the optic nerve head (ONH) and parafoveal regions in patients with multiple sclerosis (MS). Methods Fifty-two MS eyes and 21 healthy control (HC) eyes were included. There were two MS subgroups: 38 MS eyes without an optic neuritis (ON) history (MS −ON), and 14 MS eyes with an ON history (MS +ON). The OCT images were captured by high-speed 1050 nm swept-source OCT. The ONH flow index (FI) and parafoveal FI were quantified from OCT angiograms. Results The mean ONH FI was 0.160±0.010 for the HC group ...
Introduction The neuronal ceroid lipofuscinoses constitute a group of fatal inherited lysosomal storage diseases that manifest in profound neurodegeneration in the CNS. Visual impairment usually is an early symptom and selective degeneration of retinal neurons has been described in patients suffering from distinct disease subtypes. We have previously demonstrated that palmitoyl protein thioesterase 1 deficient (Ppt1-/-) mice, a model of the infantile disease subtype, exhibit progressive axonal degeneration in the optic nerve and loss of retinal ganglion cells, faithfully reflecting disease severity in the CNS. Here we performed spectral domain optical coherence tomography (OCT) in Ppt1-/- and ceroid lipofuscinosis neuronal ...
Johns Hopkins University Receives a 2014 NIH Grant for $436,412 for Imaging Neurodegeneration in Multiple Sclerosis. The principle investigator is Peter Calabresi. The program begain in 2013 and ends in 2018. Below is a summary of the proposed work. There is emerging evidence that gray matter (GM) degeneration is common in multiple sclerosis (MS), and more closely linked with disability than white matter (WM) injury. Indeed, WM volumes, as measured by high resolution MRI, wax and wane as a reflection of inflammation, whereas GM atrophy accelerates with time in MS. Whether GM degeneration purely results from WM injury or ...
Optical coherence tomography (OCT) has revolutionises the diagnosis of retinal disease based on the detection of microscopic rather than subcellular changes in retinal anatomy. However, currently the technique is limited to the detection of microscopic rather than subcellular changes in retinal anatomy. However, coherence based imaging is extremely sensitive to both changes in optical contrast and cellular events at the micrometer scale, and can generate subtle changes in the spectral content of the OCT image. Here we test the hypothesis that OCT image speckle (image texture) contains information regarding otherwise unresolvable features such as organelle changes arising in the early ...
Spectral-domain Optical coherence tomography (OCT) has shown remarkable utility in the study of retinal disease and has helped to characterize the fovea in Parkinson disease (PD) patients. We developed a detailed mathematical model based on raw OCT data to allow differentiation of foveae of PD patients from healthy controls. Of the various models we tested, a difference of a Gaussian and a polynomial was found to have "the best fit". Decision was based on mathematical evaluation of the fit of the model to the data of 45 control eyes versus 50 PD eyes. We compared the model parameters in the ...
Purpose: To calculate and validate a linear discriminant function (LDF) for Fourier domain optical coherence tomography (OCT) to improve the diagnostic ability of retinal and retinal nerve fiber layer (RNFL) thickness parameters in the detection of Alzheimer's disease (AD). Method: AD patients (n=151) and age-matched, healthy subjects (n=61) were enrolled. The Cirrus and Spectralis OCT systems were used to obtain retinal measurements and circumpapillary RNFL thickness for each participant. A LDF was calculated using all retinal and RNFL OCT measurements. Receiver operating characteristic (ROC) curves were plotted and compared among the LDF and the standard parameters provided ...
Purpose Optical coherence tomography (OCT) and Visual evoked potentials (VEPs) represent non-invasive objective examination of the visual system. While the OCT measures a morphological property of the retina (thickness of the retinal nerve fibre layer – RNFL), the VEP allows assessment a function of the visual system. There are numerous studies describing a mutual involvement of both mentioned aspects in diseases like multiple sclerosis, optic neuritis or glaucoma, however, normative studies of these relationship are missing. In our study we address this issue with an expectation to translate the findings into interpretation of pathological findings. Methods We examined a group of ...
