Publications by authors named "Schmetterer L"

Chronic venous insufficiency (CVI) is a global health concern with significant public health and individual impact. Currently available diagnostic methods cannot visualize microvenous pathologies that have shown to result in severe forms of CVI and also affect the skin. Optical coherence tomography angiography (OCTA) may close the CVI diagnostic gap by providing a fast, label-free, and non-invasive solution to visualize cutaneous microvasculature.

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Article Synopsis
  • Accurate diagnosis of Alzheimer's disease and vascular dementia is vital for timely treatment and better patient outcomes; this study focused on plasma and retinal biomarkers for differentiation among cognitive impairment groups.
  • The study involved 509 participants aged 50 and older, categorized into groups based on cognitive function using clinical assessments, neuropsychological tests, and MRI scans.
  • The findings revealed that both retinal layer thickness and plasma biomarker levels varied significantly across cognitive impairment levels, with decreases seen in retinal thickness and increases in plasma biomarkers from normal cognition to dementia.
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Background: Dementia poses a significant burden on healthcare systems. Early identification of individuals at risk for cognitive decline is crucial. The retina, an extension of the central nervous system, reflects neurodegenerative changes.

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Significance: A data-based calibration method with enhanced depolarization contrast in polarization-sensitive optical coherence tomography (PS-OCT) was developed and demonstrated effective for detecting melanin content in the eye.

Aim: We aim to mitigate the dependence between the measured depolarization metric and the intensity signal-to-noise ratio (SNR) for improved visualization of depolarizing tissues, especially in low SNR regions, and to demonstrate the enhanced depolarization contrast to evaluate melanin presence.

Approach: A function for calibrating the depolarization metric was experimentally derived from the young albino guinea pig, assuming depolarization free in the retina.

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Purpose: Currently, no standard for the measurement of retinal oxygen extraction exists. Here, we present a novel approach for measurement of retinal oxygen extraction based on two commercially available devices, namely laser speckle flowgraphy (LSFG) and retinal oximetry.

Methods: The study was conducted in a randomized, double-masked design.

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Purpose: To evaluate the impact of optical vs. illuminance factors and their duration-dependency on lens-induced hyperopia (LIH) in chick eyes.

Methods: Hyperopia was induced in one eye in chicks (10 groups; n = 126) from day 1 after hatching until day 8 using +10-diopter lenses with fellow eyes as controls.

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Purpose: To develop a quantitative tool for assessing the posterior ocular shape using widefield, volumetric optical coherence tomography (OCT) in eyes with myopia.

Methods: This observational, cross-sectional study included 178 eyes from 113 participants. Participants underwent a standardized eye examination, including ocular biometry and a custom ultrawide OCT.

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Purpose: To study the ocular and systemic factors affecting optic nerve head (ONH) perfusion data as obtained using a commercially available laser speckle flowgraphy (LSFG) device in a cohort of Caucasian subjects without ocular diseases. Also, to assess the intrasession repeatability and intersession reproducibility of ONH, macular, retinal, and choroidal perfusion.

Methods: Seventy-five healthy eyes of 75 Caucasian participants underwent LSFG and spectral-domain optical coherence tomography (SD-OCT) on the same visit.

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Article Synopsis
  • The study aimed to measure choroidal thickness in adults who underwent childhood atropine treatment for myopia using a deep learning segmentation method.
  • It found that 77.7% of the participants received atropine, which was linked to a choroid thickness increase of 20-40 μm in specific regions of the eye, after accounting for age and sex.
  • The research also indicated a relationship between greater central choroidal thickness and a lower incidence of tessellated fundus, implying childhood atropine exposure may have lasting effects on eye structure.
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Optical coherence tomography angiography (OCTA) has transformed ocular vascular imaging, revealing microvascular changes linked to various systemic diseases. This review explores its applications in diabetes, hypertension, cardiovascular diseases, and neurodegenerative diseases. While OCTA provides a valuable window into the body's microvasculature, interpreting the findings can be complex.

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Article Synopsis
  • - The study aims to evaluate the reliability and consistency of a new hyperparallel optical coherence tomography (HP-OCT) system for assessing angle closure in the eye, comparing it with the existing swept-source OCT (SS-OCT) and gonioscopy methods.
  • - Conducted on phakic subjects over 40 years old with no significant eye conditions, the research found that HP-OCT had excellent reproducibility and good agreement with both SS-OCT and gonioscopy for detecting angle closure.
  • - The findings suggest that HP-OCT not only excels in angle closure assessment but also uniquely visualizes important eye structures, potentially enhancing clinical research on fluid drainage in the eye.
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Background: The goal of the present study was to identify differences in retinal microvasculature between healthy Caucasians and healthy Asians in order to provide a better understanding of the variability between different ethnic groups.

Methods: In this cross-sectional study, 191 healthy Chinese and Caucasian participants were enrolled. They underwent optical coherence tomography angiography (OCTA) scans with Zeiss Cirrus HD-5000 Spectral-Domain with AngioPlex.

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The study aimed to evaluate the impact of compensating retinal nerve fiber layer (RNFL) thickness for demographic and anatomical factors on glaucoma detection in Chinese and Indian adults. A population-based study included 1995 healthy participants (1076 Chinese and 919 Indians) to construct a multivariable linear regression compensation model. This model was applied to 357 Chinese glaucoma patients, 357 healthy Chinese, and 357 healthy Indians using Cirrus spectral-domain optical coherence tomography (OCT).

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The choroid, which is a highly vascularized layer between the retina and sclera, is essential for supplying oxygen and nutrients to the outer retina. Choroidal vascular dysfunction has been implicated in numerous ocular diseases, including age-related macular degeneration, central serous chorioretinopathy, polypoidal choroidal vasculopathy, and myopia. Traditionally, the in vivo assessment of choroidal blood flow relies on techniques such as laser Doppler flowmetry, laser speckle flowgraphy, pneumotonometry, laser interferometry, and ultrasonic color Doppler imaging.

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Background: In vivo confocal microscopy (IVCM) is a vital tool in studying dry eye disease (DED), providing insights into morphological changes at ocular surface unit levels. This review presents the main differences in corneal structure between aqueous-deficient dry eye disease (AD-DED) and normal eyes.

Methods: A comprehensive search of PubMed, Web of Science, Embase, and MEDLINE databases from January 2000 to December 2023 was conducted.

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Phototransduction involves changes in concentration of ions and other solutes within photoreceptors and in subretinal space, which affect osmotic pressure and the associated water flow. Corresponding expansion and contraction of cellular layers can be imaged using optoretinography (ORG), based on phase-resolved optical coherence tomography (OCT). Until now, ORG could reliably detect only photoisomerization and phototransduction in photoreceptors, primarily in cones under bright stimuli.

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Purpose: Neurovascular coupling impairment and inner retinal layer thinning are early detectable retinal changes in diabetes, and both worsen during progression of diabetic retinopathy (DR). However, direct interactions between these features have not been investigated so far. Therefore, we aimed to analyze associations between the retinal functional hyperemic response to light stimulation and the thickness of individual neuroretinal layers in eyes with early non-proliferative DR.

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Background: Myopia affects 1.4 billion individuals worldwide. Notably, there is increasing evidence that choroidal thickness plays an important role in myopia and risk of developing myopia-related conditions.

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Purpose: To assess the diagnostic performance and structure-function association of retinal retardance (RR), a customized metric measured by a prototype polarization-sensitive optical coherence tomography (PS-OCT), across various stages of glaucoma.

Methods: This cross-sectional pilot study analyzed 170 eyes from 49 healthy individuals and 68 patients with glaucoma. The patients underwent PS-OCT imaging and conventional spectral-domain optical coherence tomography (SD-OCT), as well as visual field (VF) tests.

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Background/aims: To investigate whether compensating retinal nerve fibre layer (RNFL) thickness measurements for demographic and anatomical ocular factors can strengthen the structure-function relationship in patients with glaucoma.

Methods: 600 eyes from 412 patients with glaucoma (mean deviation of the visual field (MD VF) -6.53±5.

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Introduction: Myopia and its vision-threatening complications present a significant public health problem. This review aims to provide an updated overview of the multitude of known and emerging interventions to control myopia, including their potential effect, safety, and costs.

Methods: A systematic literature search of three databases was conducted.

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Spectral-domain optical coherence tomography (SDOCT) is the gold standard of imaging the eye in clinics. Penetration depth with such devices is, however, limited and visualization of the choroid, which is essential for diagnosing chorioretinal disease, remains limited. Whereas swept-source OCT (SSOCT) devices allow for visualization of the choroid these instruments are expensive and availability in praxis is limited.

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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.

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With the increasing incidences of orbital wall injuries, effective reconstruction materials and techniques are imperative for optimal clinical outcomes. In this literature review, we delve into the efficacy and potential advantages of using titanium implants coated with nanostructured hydroxyapatite for the reconstruction of the orbital wall. Titanium implants, recognized for their durability and mechanical strength, when combined with the osteoconductive properties of hydroxyapatite, present a potentially synergistic solution.

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The aim of the present study was to investigate retinal microcirculatory and functional metabolic changes in patients after they had recovered from a moderate to severe acute COVID-19 infection. Retinal perfusion was quantified using laser speckle flowgraphy. Oxygen saturation and retinal calibers were assessed with a dynamic vessel analyzer.

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