734 results on '"Ursula Schmidt-Erfurth"'
Search Results
2. Multi-modal representation learning in retinal imaging using self-supervised learning for enhanced clinical predictions
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Emese Sükei, Elisabeth Rumetshofer, Niklas Schmidinger, Andreas Mayr, Ursula Schmidt-Erfurth, Günter Klambauer, and Hrvoje Bogunović
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Multi-modal imaging ,Contrastive pre-training ,Representation learning ,Predictive modeling ,Retinal imaging ,Medicine ,Science - Abstract
Abstract Self-supervised learning has become the cornerstone of building generalizable and transferable artificial intelligence systems in medical imaging. In particular, contrastive representation learning techniques trained on large multi-modal datasets have demonstrated impressive capabilities of producing highly transferable representations for different downstream tasks. In ophthalmology, large multi-modal datasets are abundantly available and conveniently accessible as modern retinal imaging scanners acquire both 2D fundus images and 3D optical coherence tomography (OCT) scans to assess the eye. In this context, we introduce a novel multi-modal contrastive learning-based pipeline to facilitate learning joint representations for the two retinal imaging modalities. After self-supervised pre-training on 153,306 scan pairs, we show that such a pre-training framework can provide both a retrieval system and encoders that produce comprehensive OCT and fundus image representations that generalize well for various downstream tasks on three independent external datasets, explicitly focusing on clinically pertinent prediction tasks. In addition, we show that interchanging OCT with lower-cost fundus imaging can preserve the predictive power of the trained models.
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- 2024
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3. Influence of OCT biomarkers on microperimetry intra- and interdevice repeatability in diabetic macular edema
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Heiko Stino, Klaudia Birner, Laetitia Hinterhuber, Alexandra Struppe, Markus Gumpinger, Simon Schürer-Waldheim, Hrvoje Bogunovic, Ursula Schmidt-Erfurth, Andreas Pollreisz, and Gregor S. Reiter
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Medicine ,Science - Abstract
Abstract To evaluate the intra- and interdevice repeatability of microperimetry (MP) assessments in patients with diabetic macular edema (DME) two consecutive MP testings (45 fovea-centered stimuli, 4–2 staircase strategy) were performed using MP3 (NIDEK, Aichi, Japan) and MAIA (CenterVue, Padova, Italy), respectively. Intraretinal fluid (IRF) and ellipsoid zone (EZ) thickness were automatically segmented by published deep learning algorithms. Hard exudates (HEs) were annotated semi-automatically and disorganization of retinal inner layers (DRIL) was segmented manually. Point-to-point registration of MP stimuli to corresponding spectral-domain OCT (Spectralis, Heidelberg Engineering, Germany) locations was performed for both devices. Repeatability was assessed overall and in areas of disease-specific OCT biomarkers using Bland-Altmann coefficients of repeatability (CoR). A total of 3600 microperimetry stimuli were tested in 20 eyes with DME. Global CoR was high using both devices (MP3: ± 6.55 dB, MAIA: ± 7.69 dB). Higher retest variances were observed in stimuli with IRF (MP3: CoR ± 7.4 dB vs. ± 6.0 dB, p = 0.001, MAIA: CoR ± 9.2dB vs. ± 6.8 dB, p = 0.002) and DRIL on MP3 (CoR ± 6.9 dB vs. ± 3.2 dB, p
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- 2024
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4. Quantitative comparison of automated OCT and conventional FAF-based geographic atrophy measurements in the phase 3 OAKS/DERBY trials
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Julia Mai, Gregor S. Reiter, Sophie Riedl, Wolf-Dieter Vogl, Amir Sadeghipour, Emma Foos, Alex McKeown, Hrvoje Bogunovic, and Ursula Schmidt-Erfurth
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Geographic atrophy ,Optical coherence tomography ,Fundus autofluorescence ,Artificial intelligence ,Deep learning ,Medicine ,Science - Abstract
Abstract With the approval of the first two substances for the treatment of geographic atrophy (GA) secondary to age-related macular degeneration (AMD), a standardized monitoring of patients treated with complement inhibitors in clinical practice is needed. Optical coherence tomography (OCT) provides high-resolution access to the retinal pigment epithelium (RPE) and neurosensory layers, such as the ellipsoid zone (EZ), which further enhances the understanding of disease progression and therapeutic effects in GA compared to conventional fundus autofluorescence (FAF). In addition, artificial intelligence-based methodology allows the identification and quantification of GA-related pathology on OCT in an objective and standardized manner. The purpose of this study was to comprehensively evaluate automated OCT monitoring for GA compared to reading center-based manual FAF measurements in the largest successful phase 3 clinical trial data of complement inhibitor therapy to date. Automated OCT analysis of RPE loss showed a high and consistent correlation to manual GA measurements on conventional FAF. EZ loss on OCT was generally larger than areas of RPE loss, supporting the hypothesis that EZ loss exceeds underlying RPE loss as a fundamental pathophysiology in GA progression. Automated OCT analysis is well suited to monitor disease progression in GA patients treated in clinical practice and clinical trials.
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- 2024
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5. Linking disease activity with optical coherence tomography angiography in neovascular age related macular degeneration using artificial intelligence
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Markus Schranz, Hrvoje Bogunovic, Gabor Deak, Amir Sadeghipour, Gregor Sebastian Reiter, and Ursula Schmidt-Erfurth
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Age-related macular degeneration ,Optical coherence tomography angiography ,Retinal fluid ,Deep learning ,Macular neovascular membrane ,Medicine ,Science - Abstract
Abstract To investigate quantitative associations between AI-assessed disease activity and optical coherence tomography angiography (OCTA)-derived parameters in patients with neovascular age-related macular degeneration (nAMD) undergoing anti-VEGF therapy. OCTA and SD-OCT images obtained from multicenter, randomized study data were evaluated. A deep learning algorithm (RetInSight) was used to detect and quantify macular fluid on SD-OCT. Mixed effects models were applied to evaluate correlations between fluid volumes, macular neovascularization (MNV)-type and OCTA-derived MNV parameters; lesion size (LS) and vessel area (NVA). 230 patients were included. A significant positive correlation was observed between SRF and NVA (estimate = 199.8 nl/mm2, p = 0.023), while a non-significant but negative correlation was found between SRF and LS (estimate = − 71.3 nl/mm2, p = 0.126). The presence of Type I and Type II MNV was associated with significantly less intraretinal fluid (IRF) compared to Type III MNV (estimate type I:− 52.1 nl, p = 0.019; estimate type II:− 51.7 nl, p = 0.021). A significant correlation was observed between pigment epithelial detachment (PED) and the interaction between NVA and LS (estimate:28.97 nl/mm2; p = 0.012). Residual IRF at week 12 significantly correlated to baseline NVA (estimate:38.1 nl/mm2; p = 0.015) and LS (estimate:− 22.6 nl/mm2; p = 0.012). Fluid in different compartments demonstrated disparate associations with MNV OCTA features. While IRF at baseline was most pronounced in type III MNV, residual IRF was driven by neovascular MNV characteristics. Greater NVA in proportion to LS was associated with higher amounts of SRF and PED. The correlation between these parameters may represent MNV maturation and can be used as a biomarker for resolution of disease activity. AI-based OCT analysis allows for a deeper understanding of neovascular disease in AMD and the potential to adjust therapeutic strategies to optimize outcomes through precision medicine.
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- 2024
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6. Vitrectomy versus scleral buckle for retinal detachment without posterior vitreous detachment
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Ioanna Dimakopoulou, Georgios Mylonas, Johannes Iby, Alexandra Sedova, Marlene Hollaus, Stefan Sacu, Michael Georgopoulos, and Ursula Schmidt-Erfurth
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Retinal detachment ,Posterior vitreous detachment ,Vitrectomy ,Scleral buckling ,Medicine ,Science - Abstract
Abstract To compare the effectiveness and safety of scleral buckling and pars plana vitrectomy in treating retinal detachment without posterior vitreous detachment. A total of 88 eyes of 83 patients with retinal detachment without prior posterior vitreous detachment were investigated retrospectively. Group A comprised patients who underwent scleral buckling (n = 47) and Group B (n = 36) patients who were treated with pars plana vitrectomy. Anatomical success, postoperative visual acuity, and ocular adverse events were evaluated. The primary and final anatomical success rate showed a nonsignificant difference (p = 0.465 and p = 0.37 respectively). No significant difference was observed in the reoperation rate or development of epiretinal membrane between the groups (p = 0.254 and p = 0.254 respectively). However, scleral buckling resulted in significantly better visual acuity at the last follow-up (0.12 ± 0.23) compared to pars plana vitrectomy (0.37 ± 0.46, p = 0.001). The incidence of cataract progression was also significantly higher in the pars plana vitrectomy group (46%) compared to the scleral buckling group (10%, p
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- 2024
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7. AI-based support for optical coherence tomography in age-related macular degeneration
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Virginia Mares, Marcio B. Nehemy, Hrvoje Bogunovic, Sophie Frank, Gregor S. Reiter, and Ursula Schmidt-Erfurth
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Age-related macular degeneration ,Anti-VEGF ,Artificial intelligence ,Choroidal neovascularization ,Deep learning ,Drusen ,Ophthalmology ,RE1-994 - Abstract
Abstract Artificial intelligence (AI) has emerged as a transformative technology across various fields, and its applications in the medical domain, particularly in ophthalmology, has gained significant attention. The vast amount of high-resolution image data, such as optical coherence tomography (OCT) images, has been a driving force behind AI growth in this field. Age-related macular degeneration (AMD) is one of the leading causes for blindness in the world, affecting approximately 196 million people worldwide in 2020. Multimodal imaging has been for a long time the gold standard for diagnosing patients with AMD, however, currently treatment and follow-up in routine disease management are mainly driven by OCT imaging. AI-based algorithms have by their precision, reproducibility and speed, the potential to reliably quantify biomarkers, predict disease progression and assist treatment decisions in clinical routine as well as academic studies. This review paper aims to provide a summary of the current state of AI in AMD, focusing on its applications, challenges, and prospects.
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- 2024
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8. Interactive Deep Learning-Based Retinal OCT Layer Segmentation Refinement by Regressing Translation Maps
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Guilherme Aresta, Teresa Araujo, Botond Fazekas, Julia Mai, Ursula Schmidt-Erfurth, and Hrvoje Bogunovic
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Image segmentation ,interactive annotation ,deep learning ,human-in-the-loop ,optical coherence tomography ,retina ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Retinal layer segmentation in optical coherence tomography (OCT) is essential for the diagnosis and follow-up of several diseases. Despite the success of deep learning approaches for this task, their clinical applicability is limited, since they neither account for pathologies other than those present in the training set nor for the specialists’ subjectivity. Thus, we propose an interactive layer segmentation approach that allows to obtain an initial segmentation and, more importantly, to interactively correct those segmentations. Our deep learning-based approach predicts the translation required to correct layer boundary segmentations by regressing pixel-wise translation maps that account for the user input. The method is designed to allow for segmentation correction by interactions with point-clicks or line-scribbles. Additionally, the system outputs a coordinate-wise confidence, allowing to automatically identify regions of possible segmentation failure that may require user attention. We extensively validate our approach on multiple private and public datasets with different pathomorphological complexities, achieving state-of-the-art performance, while allowing for a simple and efficient user interaction.
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- 2024
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9. Inter and intradevice assessment of microperimetry testing in aging eyes
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Leonard M. Coulibaly, Hamza Mohamed, Philipp Fuchs, Ursula Schmidt-Erfurth, and Gregor S. Reiter
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Medicine ,Science - Abstract
Abstract Microperimetry (MP) is a psychometric examination combining retinal imaging and functional sensitivity testing with an increasing importance due to its potential use as clinical study outcome. We investigated the repeatability of pointwise retinal sensitivity (PWS) on the most advanced commercially available MP devices under their standard setting in a healthy aging population. Two successive MP examinations on both MP-3 (NIDEK CO., Ltd., Gamagori, Japan) and MAIA (CenterVue S.p.A. (iCare), Padova, Italy) were performed on healthy aging subjects in a randomized order. PWS repeatability was analysed for different macular regions and age groups using Bland-Altmann coefficients of repeatability (CoR). A total of 3600 stimuli from 20 healthy individuals with a mean age of 70 (11) years were included. Mean CoR in dB were ±4.61 for MAIA and ±4.55 for MP-3 examinations. A lower repeatability (p=0.005) was detected in the central millimetre on MAIA examinations. Higher subject age was associated with a lower repeatability of PWS on both devices (both p=0.003). Intra-device correlation was good (MAIA: 0.79 [0.76–0.81]; MP-3: 0.72 [0.68–0.76]) whereas a moderate mean inter-device correlation (0.6 [0.55–0.65]) could be detected. In conclusion, older subjects and the foveal region are associated with a worse pointwise repeatability.
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- 2024
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10. Dynamics and patterns of recurrence in neovascular AMD during real-world management using automated fluid monitoring
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Veronika Prenner, Ursula Schmidt-Erfurth, Philipp Fuchs, Oliver Leingang, Leonard Mana Coulibaly, Hrvoje Bogunovic, Daniel Barthelmes, and Gregor Sebastian Reiter
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Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
In this retrospective longitudinal observational study, data from one site of the Fight Retinal Blindness! Registry (University of Zurich, Switzerland) was used to investigate the quantity and distribution of recurrent fluid in neovascular age-related macular degeneration (nAMD). Study eye eligibility required treatment-naïve nAMD, receiving at least three anti-vascular endothelial growth factor injections, followed by a treatment discontinuation of at least six months and subsequence fluid recurrence. To quantify fluid, a regulatory approved deep learning algorithm (Vienna Fluid Monitor, RetInSight, Vienna, Austria) was used. Fifty-six eyes of 56 patients with a mean age of 76.29 ± 6.58 years at baseline fulfilled the inclusion criteria. From baseline to the end of the first treatment-free interval, SRF volume had decreased significantly (58.0 nl (IQR 10–257 nl) to 8.73 nl (IQR 1–100 nl), p
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- 2024
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11. A Systematic Prospective Comparison of Fluid Volume Evaluation across OCT Devices Used in Clinical Practice
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Klaudia Kostolna, MD, Gregor S. Reiter, MD, PhD, Sophie Frank, MD, Leonard M. Coulibaly, MD, Philipp Fuchs, MD, Veronika Röggla, MD, PhD, Markus Gumpinger, MSc, Gabriel P. Leitner Barrios, Virginia Mares, MD, Hrvoje Bogunovic, PhD, and Ursula Schmidt-Erfurth, MD
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Intraretinal fluid ,Neovascular age-related macular degeneration ,Optical coherence tomography ,Pigment epithelial detachment ,Subretinal fluid ,Ophthalmology ,RE1-994 - Abstract
Objective: Treatment decisions in neovascular age-related macular degeneration (nAMD) are mainly based on subjective evaluation of OCT. The purpose of this cross-sectional study was to provide a comparison of qualitative and quantitative differences between OCT devices in a systematic manner. Design: Prospective, cross-sectional study. Subjects: One hundred sixty OCT volumes, 40 eyes of 40 patients with nAMD. Methods: Patients from clinical practice were imaged with 4 different OCT devices during one visit: (1) Spectralis Heidelberg; (2) Cirrus; (3) Topcon Maestro2; and (4) Topcon Triton. Intraretinal fluid (IRF), subretinal fluid (SRF), and pigment epithelial detachment (PED) were manually annotated in all cubes by trained human experts to establish fluid measurements based on expert-reader annotations. Intraretinal fluid, SRF, and PED volume were quantified in nanoliters (nL). Bland–Altman plots were created to analyze the agreement of measurements in the central 1 and 6 mm. The Friedman test was performed to test for significant differences in the central 1, 3, and 6 mm. Main Outcome Measures: Intraretinal fluid, SRF, and PED volume. Results: In the central 6 mm, there was a trend toward higher IRF and PED volumes in Spectralis images compared with the other devices and no differences in SRF volume. In the central 1 mm, the standard deviation of the differences ranged from ± 3 nL to ± 6 nL for IRF, from ± 3 nL to ± 4 nL for SRF, and from ± 7 nL to ± 10 nL for PED in all pairwise comparisons. Manually annotated IRF and SRF volumes showed no significant differences in the central 1 mm. Conclusions: Fluid volume quantification achieved excellent reliability in all 3 retinal compartments on images obtained from 4 OCT devices, particularly for clinically relevant IRF and SRF values. Although fluid volume quantification is reliable in all 4 OCT devices, switching OCT devices might lead to deviating fluid volume measurements with higher agreement in the central 1 mm compared with the central 6 mm, with highest agreement for SRF volume in the central 1 mm. Understanding device-dependent differences is essential for expanding the interpretation and implementation of pixel-wise fluid volume measurements in clinical practice and in clinical trials. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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- 2024
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12. Automated deep learning-based AMD detection and staging in real-world OCT datasets (PINNACLE study report 5)
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Oliver Leingang, Sophie Riedl, Julia Mai, Gregor S. Reiter, Georg Faustmann, Philipp Fuchs, Hendrik P. N. Scholl, Sobha Sivaprasad, Daniel Rueckert, Andrew Lotery, Ursula Schmidt-Erfurth, and Hrvoje Bogunović
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Medicine ,Science - Abstract
Abstract Real-world retinal optical coherence tomography (OCT) scans are available in abundance in primary and secondary eye care centres. They contain a wealth of information to be analyzed in retrospective studies. The associated electronic health records alone are often not enough to generate a high-quality dataset for clinical, statistical, and machine learning analysis. We have developed a deep learning-based age-related macular degeneration (AMD) stage classifier, to efficiently identify the first onset of early/intermediate (iAMD), atrophic (GA), and neovascular (nAMD) stage of AMD in retrospective data. We trained a two-stage convolutional neural network to classify macula-centered 3D volumes from Topcon OCT images into 4 classes: Normal, iAMD, GA and nAMD. In the first stage, a 2D ResNet50 is trained to identify the disease categories on the individual OCT B-scans while in the second stage, four smaller models (ResNets) use the concatenated B-scan-wise output from the first stage to classify the entire OCT volume. Classification uncertainty estimates are generated with Monte-Carlo dropout at inference time. The model was trained on a real-world OCT dataset, 3765 scans of 1849 eyes, and extensively evaluated, where it reached an average ROC-AUC of 0.94 in a real-world test set.
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- 2023
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13. Impact of Choroidal Melanoma Characteristics on Progression-Free Survival in Patients Undergoing Hypofractionated Stereotactic Photon Radiotherapy
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Reinhard Told, Judith Kreminger, Ursula Schmidt-Erfurth, Roman Dunavoelgyi, and Adrian Reumueller
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Choroidal melanoma ,Monitoring ,Ultrasonography ,Tumor characteristics ,Ophthalmology ,RE1-994 - Abstract
Abstract Introduction In an effort to replace ultrasonography-based thickness measurements, we investigated whether choroidal melanoma characteristics are related to progression-free survival (PFS) in patients monitored after linear accelerator (LINAC)-based hypofractionated stereotactic photon radiotherapy. Methods In a retrospective dataset, we used a linear mixed model to assess the associations between PFS and tumor characteristics; in particular, thickness, largest basal diameter (LBD), base area and volume. Results Thickness and LBD are statistically significantly associated with PFS. In a subgroup of 16 patients undergoing enucleation due to melanoma recurrence or progression, there were statistically significant changes in mean thickness and LBD before surgery. Mean PFS was 42 ± 30 months. Conclusion Ultrasonography-based thickness measurements may not be necessary for treated choroidal melanoma monitoring; instead, we propose sequential LBD assessments, which should preferably be performed using fundus photography in future.
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- 2023
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14. Few-shot out-of-distribution detection for automated screening in retinal OCT images using deep learning
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Teresa Araújo, Guilherme Aresta, Ursula Schmidt-Erfurth, and Hrvoje Bogunović
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Medicine ,Science - Abstract
Abstract Deep neural networks have been increasingly proposed for automated screening and diagnosis of retinal diseases from optical coherence tomography (OCT), but often provide high-confidence predictions on out-of-distribution (OOD) cases, compromising their clinical usage. With this in mind, we performed an in-depth comparative analysis of the state-of-the-art uncertainty estimation methods for OOD detection in retinal OCT imaging. The analysis was performed within the use-case of automated screening and staging of age-related macular degeneration (AMD), one of the leading causes of blindness worldwide, where we achieved a macro-average area under the curve (AUC) of 0.981 for AMD classification. We focus on a few-shot Outlier Exposure (OE) method and the detection of near-OOD cases that share pathomorphological characteristics with the inlier AMD classes. Scoring the OOD case based on the Cosine distance in the feature space from the penultimate network layer proved to be a robust approach for OOD detection, especially in combination with the OE. Using Cosine distance and only 8 outliers exposed per class, we were able to improve the near-OOD detection performance of the OE with Reject Bucket method by $$\approx$$ ≈ 10% compared to without OE, reaching an AUC of 0.937. The Cosine distance served as a robust metric for OOD detection of both known and unknown classes and should thus be considered as an alternative to the reject bucket class probability in OE approaches, especially in the few-shot scenario. The inclusion of these methodologies did not come at the expense of classification performance, and can substantially improve the reliability and trustworthiness of the resulting deep learning-based diagnostic systems in the context of retinal OCT.
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- 2023
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15. Potential for Treatment Interval Extension in Eyes with nAMD Disease Activity Post Loading Phase in HAWK and HARRIER
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Ramin Tadayoni, Glenn J. Jaffe, Frank G. Holz, Ursula Schmidt-Erfurth, Kanji Takahashi, Chui Ming Gemmy Cheung, Seenu M. Hariprasad, Kinfemichael Gedif, Rasmus Olsen, Catherine Best, Franklin Igwe, and Peter K. Kaiser
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Anti-VEGF therapy ,Brolucizumab ,Disease activity ,Interval extension ,Neovascular age-related macular degeneration ,Ophthalmology ,RE1-994 - Abstract
Abstract Introduction The HAWK and HARRIER studies evaluated the efficacy and safety of brolucizumab versus aflibercept in treatment-naïve eyes with neovascular age-related macular degeneration. Based on the study design, brolucizumab-treated eyes adjusted to a q8w regimen because the presence of disease activity (DA) at the end of the matched loading phase (Week 16) could not subsequently extend to a q12w interval. The aim of this post hoc analysis was to assess subsequent DA in this subgroup to determine the potential for interval extensions during the first year of treatment. Methods Pooled data from the brolucizumab 6 mg arms and aflibercept arms of HAWK and HARRIER were included. Presence of DA was determined by the masked investigator based on their assessment of functional and anatomical parameters measured by optical coherence tomography. DA was compared at DA assessments, conducted at Weeks 16, 20, 32, and 44; fluid was also assessed at the primary analysis at Week 48. Results Fewer brolucizumab- (22.8%) than aflibercept-treated (32.2%) eyes had DA at the first DA assessment at Week 16. In eyes with investigator-identified DA at Week 16, BCVA change from baseline to Week 96 was comparable between treatment arms. Fewer brolucizumab- than aflibercept-treated eyes had DA at each subsequent DA assessment in Year 1: 31.8% vs 39.1% (Week 20), 27.3% vs 43.5% (Week 32), and 17.3% vs 31.2% (Week 44). Fewer eyes treated with brolucizumab than aflibercept had intraretinal and/or subretinal fluid: 35.3% vs 43.5% (Week 20), 55.8% vs 69.6% (Week 32), 30.0% vs 43.1% (Week 44), and 48.6% vs 68.6% (Week 48). Conclusion These findings indicate that, in eyes that still had DA 8 weeks after the final dose of loading phase, brolucizumab-treated eyes had improved fluid resolution and higher potential for treatment interval extension than aflibercept-treated eyes during the first year of treatment.
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- 2023
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16. Clinical validation for automated geographic atrophy monitoring on OCT under complement inhibitory treatment
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Julia Mai, Dmitrii Lachinov, Sophie Riedl, Gregor S. Reiter, Wolf-Dieter Vogl, Hrvoje Bogunovic, and Ursula Schmidt-Erfurth
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Medicine ,Science - Abstract
Abstract Geographic atrophy (GA) represents a late stage of age-related macular degeneration, which leads to irreversible vision loss. With the first successful therapeutic approach, namely complement inhibition, huge numbers of patients will have to be monitored regularly. Given these perspectives, a strong need for automated GA segmentation has evolved. The main purpose of this study was the clinical validation of an artificial intelligence (AI)-based algorithm to segment a topographic 2D GA area on a 3D optical coherence tomography (OCT) volume, and to evaluate its potential for AI-based monitoring of GA progression under complement-targeted treatment. 100 GA patients from routine clinical care at the Medical University of Vienna for internal validation and 113 patients from the FILLY phase 2 clinical trial for external validation were included. Mean Dice Similarity Coefficient (DSC) was 0.86 ± 0.12 and 0.91 ± 0.05 for total GA area on the internal and external validation, respectively. Mean DSC for the GA growth area at month 12 on the external test set was 0.46 ± 0.16. Importantly, the automated segmentation by the algorithm corresponded to the outcome of the original FILLY trial measured manually on fundus autofluorescence. The proposed AI approach can reliably segment GA area on OCT with high accuracy. The availability of such tools represents an important step towards AI-based monitoring of GA progression under treatment on OCT for clinical management as well as regulatory trials.
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- 2023
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17. Comparison of two ultra-widefield color-fundus imaging devices for visualization of retinal periphery and microvascular lesions in patients with early diabetic retinopathy
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Heiko Stino, Susanna Riessland, Aleksandra Sedova, Felix Datlinger, Stefan Sacu, Ursula Schmidt-Erfurth, and Andreas Pollreisz
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Medicine ,Science - Abstract
Abstract Comparison of two ultra-widefield (UWF) color-fundus (CF) imaging devices in diabetic patients for visualization of retinal periphery and detection of early microvascular lesions. The total gradable areas (TGA) seen on non-mydriatic CF-images of two UWF-imaging devices (Optos Daytona P200T; Zeiss Clarus 700) were compared and differences in projected area measured. Retinal periphery outside the 7 standard fields (7SF) was divided into: F3 temporal, F4 superotemporal, F5 inferotemporal, F6 superonasal, F7 inferonasal. DR stage was evaluated in the 7SF and the TGA on images of both devices and compared using Cohens κ. 67 eyes of 67 patients (52.5 ± 15.3 years) were analysed. DR stages in the 7SF were no (n = 36 Optos, n = 35 Clarus), mild (n = 16 Optos, n = 17 Clarus), and moderate DR (n = 15). Optos depicted significantly more area in F3 (median [interquartile range]; 2.41% [1.06–4.11] vs 0% [0–0], P
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- 2022
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18. Exploring Healthy Retinal Aging with Deep Learning
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Martin J. Menten, PhD, Robbie Holland, MSc, Oliver Leingang, PhD, Hrvoje Bogunović, PhD, Ahmed M. Hagag, MD, Rebecca Kaye, MD, Sophie Riedl, MD, Ghislaine L. Traber, MD, Osama N. Hassan, MSc, Nick Pawlowski, PhD, Ben Glocker, PhD, Lars G. Fritsche, PhD, Hendrik P.N. Scholl, MD, Sobha Sivaprasad, MD, Ursula Schmidt-Erfurth, MD, Daniel Rueckert, PhD, and Andrew J. Lotery, MD
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Aging ,Biomarker discovery ,Deep learning ,Machine learning ,Retina ,Ophthalmology ,RE1-994 - Abstract
Purpose: To study the individual course of retinal changes caused by healthy aging using deep learning. Design: Retrospective analysis of a large data set of retinal OCT images. Participants: A total of 85 709 adults between the age of 40 and 75 years of whom OCT images were acquired in the scope of the UK Biobank population study. Methods: We created a counterfactual generative adversarial network (GAN), a type of neural network that learns from cross-sectional, retrospective data. It then synthesizes high-resolution counterfactual OCT images and longitudinal time series. These counterfactuals allow visualization and analysis of hypothetical scenarios in which certain characteristics of the imaged subject, such as age or sex, are altered, whereas other attributes, crucially the subject’s identity and image acquisition settings, remain fixed. Main Outcome Measures: Using our counterfactual GAN, we investigated subject-specific changes in the retinal layer structure as a function of age and sex. In particular, we measured changes in the retinal nerve fiber layer (RNFL), combined ganglion cell layer plus inner plexiform layer (GCIPL), inner nuclear layer to the inner boundary of the retinal pigment epithelium (INL-RPE), and retinal pigment epithelium (RPE). Results: Our counterfactual GAN is able to smoothly visualize the individual course of retinal aging. Across all counterfactual images, the RNFL, GCIPL, INL-RPE, and RPE changed by −0.1 μm ± 0.1 μm, −0.5 μm ± 0.2 μm, −0.2 μm ± 0.1 μm, and 0.1 μm ± 0.1 μm, respectively, per decade of age. These results agree well with previous studies based on the same cohort from the UK Biobank population study. Beyond population-wide average measures, our counterfactual GAN allows us to explore whether the retinal layers of a given eye will increase in thickness, decrease in thickness, or stagnate as a subject ages. Conclusion: This study demonstrates how counterfactual GANs can aid research into retinal aging by generating high-resolution, high-fidelity OCT images, and longitudinal time series. Ultimately, we envision that they will enable clinical experts to derive and explore hypotheses for potential imaging biomarkers for healthy and pathologic aging that can be refined and tested in prospective clinical trials. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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- 2023
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19. Management of cataract surgery in Lowe syndrome
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Katharina Eibenberger, Sandra Rezar-Dreindl, Franz Pusch, Ursula Schmidt-Erfurth, and Eva Stifter
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lowe syndrome ,congenital cataract ,pediatric cataract surgery ,Ophthalmology ,RE1-994 - Abstract
AIM: To evaluate the ophthalmic and anesthesiologic management of cataract surgery in children with Lowe syndrome receiving lens removal, the development and management of secondary glaucoma. METHODS: This retrospective case series included 12 eyes of 6 children with genetically verified Lowe syndrome receiving cataract removal. Information regarding the type and duration of surgery and total anesthesia time were recorded. Additionally, intra- and postoperative complications were noted as well as clinical examinations such as visual acuity and funduscopy. RESULTS: All children received simultaneous bilateral cataract surgery at the mean age of 8.98±3.58wk. Lensectomy combined with posterior capsulotomy and anterior vitrectomy was performed in all children. The mean time for cataract surgery per eye was 35.83±8.86min, whereas the total time of surgery was 153.33±22.11min. The mean extubation time and duration at recovery room was 42.33±22.60min and 130.00±64.37min, respectively. During surgery, a decrease of oxygen saturation below 93% was found in only one child. During the postoperative follow-up, nystagmus (6 children) and strabismus (5 children) was commonly found in contrast to no case of visual axis opacification. Secondary glaucoma developed in five eyes of three children, which was treated with topical eye drops in only one child. A trabeculectomy was performed in both eyes of one child, whereas removal of syechia and an iridectomy in one eye of one child. CONCLUSION: Bilateral simultaneous cataract surgery under general anesthesia is a safe surgical procedure in Lowe syndrome children. The glaucoma screening with intraocular pressure measurements is crucial in the postoperative management of Lowe syndrome patients to avoid additional visual impairment.
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- 2022
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20. Intraprocedural OCT monitoring of the immediate treatment response during indocyanine green angiography-guided laser therapy of teleangiectatic capillaries in diabetic macular edema
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Felix Datlinger, Anja Datlinger, Andreas Pollreisz, Stefan Sacu, Ursula Schmidt-Erfurth, and Peter Datlinger
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Medicine ,Science - Abstract
Abstract In this retrospective study the morphological response of teleangiectatic capillaries (TCs) to focal laser treatment and the functional and morphological outcome after Indocyanine green angiography (ICGA)-guided laser therapy was evaluated. TCs in eyes with diabetic macular edema (DME) were treated with laser therapy. The immediate and subsequent reaction of the TCs lumina to direct photocoagulation was monitored with customized OCT single scans. Additionally, patients were treated with intravitreal anti-VEGF as needed. 12 eyes of 9 patients with treatment naive (6 eyes) and pretreated (6 eyes) DME were followed-up for a mean of 24 months (± 8.1SD). Best-corrected visual acuity improved from 0.25 logMar (± 0.2SD) to 0.12 (± 0.10SD; p = 0.06) at each patient’s last visit. During laser treatment a darkening of the TCs lumina was achieved in 91.3% of lesions. All these lesions fully resolved, whereas TCs, which showed no darkening of their lumen in OCT persisted and required re-treatment with laser. Additional anti-VEGF injections were indicated in only one eye (8.3%). The darkening of the TCs lumina visible in OCT might provide an image-biomarker that indicates successful coagulation of aneurysmatic lesions. Consequently, a significant functional and morphological improvement with need for anti-VEGF treatment in only one eye, was achieved. Information concerning the registration of the trial: date of registration: 11th of december, 2019. Trial registration number: 107/2019.
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- 2022
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21. Optical coherence tomography in multiple sclerosis: A 3‐year prospective multicenter study
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Friedemann Paul, Peter A. Calabresi, Frederik Barkhof, Ari J. Green, Randy Kardon, Jaume Sastre‐Garriga, Sven Schippling, Patrick Vermersch, Shiv Saidha, Bianca S. Gerendas, Ursula Schmidt‐Erfurth, Catherine Agoropoulou, Ying Zhang, Gustavo Seifer, and Axel Petzold
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Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Objective To evaluate changes over 3 years in the thickness of inner retinal layers including the peripapillary retinal nerve fiber layer (pRNFL), and combined macular ganglion cell and inner plexiform layers (mGCIPL), in individuals with relapsing‐remitting multiple sclerosis (RRMS) versus healthy controls; to determine whether optical coherence tomography (OCT) is sufficiently sensitive and reproducible to detect small degrees of neuroaxonal loss over time that correlate with changes in brain volume and disability progression as measured by the Expanded Disability Status Scale (EDSS). Methods Individuals with RRMS from 28 centers (n = 333) were matched with 64 healthy participants. OCT scans were performed on Heidelberg Spectralis machines (at baseline; 1 month; 6 months; 6‐monthly thereafter). Results OCT measurements were highly reproducible between baseline and 1 month (intraclass correlation coefficient >0.98). Significant inner retinal layer thinning was observed in individuals with multiple sclerosis (MS) compared with controls regardless of previous MS‐associated optic neuritis––group differences (95% CI) over 3 years: pRNFL: −1.86 (−2.54, −1.17) µm; mGCIPL: −2.03 (−2.78, −1.28) µm (both p 5 years (pRNFL: p
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- 2021
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22. Predicting treat-and-extend outcomes and treatment intervals in neovascular age-related macular degeneration from retinal optical coherence tomography using artificial intelligence
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Hrvoje Bogunović, Virginia Mares, Gregor S. Reiter, and Ursula Schmidt-Erfurth
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neovascular age related macular degeneration ,optical coherence tomography ,anti-VEGF (vascular endothelial growth factor) ,image analysis ,retina ,machine learning ,Medicine (General) ,R5-920 - Abstract
PurposeTo predict visual outcomes and treatment needs in a treat & extend (T&E) regimen in neovascular age-related macular degeneration (nAMD) using a machine learning model based on quantitative optical coherence tomography (OCT) imaging biomarkers.Materials and methodsStudy eyes of 270 treatment-naïve subjects, randomized to receiving ranibizumab therapy in the T&E arm of a randomized clinical trial were considered. OCT volume scans were processed at baseline and at the first follow-up visit 4 weeks later. Automated image segmentation was performed, where intraretinal (IRF), subretinal (SRF) fluid, pigment epithelial detachment (PED), hyperreflective foci, and the photoreceptor layer were delineated using a convolutional neural network (CNN). A set of respective quantitative imaging biomarkers were computed across an Early Treatment Diabetic Retinopathy Study (ETDRS) grid to describe the retinal pathomorphology spatially and its change after the first injection. Lastly, using the computed set of OCT features and available clinical and demographic information, predictive models of outcomes and retreatment intervals were built using machine learning and their performance evaluated with a 10-fold cross-validation.ResultsData of 228 evaluable patients were included, as some had missing scans or were lost to follow-up. Of those patients, 55% reached and maintained long (8, 10, 12 weeks) and another 45% stayed at short (4, 6 weeks) treatment intervals. This provides further evidence for a high disease activity in a major proportion of patients. The model predicted the extendable treatment interval group with an AUROC of 0.71, and the visual outcome with an AUROC of up to 0.87 when utilizing both, clinical and imaging features. The volume of SRF and the volume of IRF, remaining at the first follow-up visit, were found to be the most important predictive markers for treatment intervals and visual outcomes, respectively, supporting the important role of quantitative fluid parameters on OCT.ConclusionThe proposed Artificial intelligence (AI) methodology was able to predict visual outcomes and retreatment intervals of a T&E regimen from a single injection. The result of this study is an urgently needed step toward AI-supported management of patients with active and progressive nAMD.
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- 2022
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23. Influence of lens opacities and cataract severity on quantitative fundus autofluorescence as a secondary outcome of a randomized clinical trial
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Gregor S. Reiter, Luca Schwarzenbacher, Daniel Schartmüller, Veronika Röggla, Christina Leydolt, Rupert Menapace, Ursula Schmidt-Erfurth, and Stefan Sacu
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Medicine ,Science - Abstract
Abstract The aim of this study is to investigate the impact of age-related lens opacities and advanced cataract, quantified by LOCS III grading, on quantitative autofluorescence (qAF) measurements in patients before and after cataract surgery. Images from a randomized controlled trial evaluating the impact of femtosecond-laser assisted cataract surgery (FLACS) on retinal thickness were analyzed post-hoc. One-hundred and twenty eyes from 60 consecutive patients with age-related cataract were included and assessed with qAF and optical coherence tomography (OCT) before, 1, 3 and 6 weeks after cataract surgery (randomized 1:1 to FLACS or phacoemulsification). LOCS III grading was performed before surgery. Pre- to post-surgical qAF values, as well as the impact of LOCS III gradings, surgery technique, gender, axial length and age on post-surgery qAF values was investigated using generalized linear mixed models. For this analysis, 106 eyes from 53 patients were usable. No difference in qAF was found between FLACS and phacoemulsification (p > 0.05) and results were pooled for the total cohort. Mean pre-surgical qAF was 89.45 ± 44.9 qAF units, with a significant mean increase of 178.4–191.6% after surgery (p 0.05). Higher LOCS III cortical opacity quantifications were associated with a significantly greater increase in qAF after surgery (estimate: 98.56, p = 0.006) and nuclear opacities showed a trend toward an increased change (estimate: 48.8, p = 0.095). Considerable interactions were identified between baseline qAF and cortical opacities, nuclear opacities and posterior subcapsular opacities, as well as nuclear opacities and cortical opacities (p = 0.012, p = 0.064 and p = 0.069, respectively). Quantitative autofluorescence signals are significantly reconstituted after cataract surgery and LOCS III gradings are well associated with post-surgical qAF values. Careful consideration of age-related lens opacities is vital for the correct interpretation of qAF, especially in retinal diseases affecting the elderly. ClinicalTrials.gov Identifier: NCT03465124.
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- 2021
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24. Spatio-temporal alterations in retinal and choroidal layers in the progression of age-related macular degeneration (AMD) in optical coherence tomography
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Wolf-Dieter Vogl, Hrvoje Bogunović, Sebastian M. Waldstein, Sophie Riedl, and Ursula Schmidt-Erfurth
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Medicine ,Science - Abstract
Abstract Age-related macular degeneration (AMD) is the predominant cause of vision loss in the elderly with a major impact on ageing societies and healthcare systems. A major challenge in AMD management is the difficulty to determine the disease stage, the highly variable progression speed and the risk of conversion to advanced AMD, where irreversible functional loss occurs. In this study we developed an optical coherence tomography (OCT) imaging based spatio-temporal reference frame to characterize the morphologic progression of intermediate age-related macular degeneration (AMD) and to identify distinctive patterns of conversion to the advanced stages macular neovascularization (MNV) and macular atrophy (MA). We included 10,040 OCT volumes of 518 eyes with intermediate AMD acquired according to a standardized protocol in monthly intervals over two years. Two independent masked retina specialists determined the time of conversion to MNV or MA. All scans were aligned to a common reference frame by intra-patient and inter-patient registration. Automated segmentations of retinal layers and the choroid were computed and en-face maps were transformed into the common reference frame. Population maps were constructed in the subgroups converting to MNV (n=135), MA (n=50) and in non-progressors (n=333). Topographically resolved maps of changes were computed and tested for statistical significant differences. The development over time was analysed by a joint model accounting for longitudinal and right-censoring aspect. Significantly enhanced thinning of the outer nuclear layer (ONL) and retinal pigment epithelium (RPE)–photoreceptorinner segment/outer segment (PR-IS/OS) layers within the central 3 mm and a faster thinning speed preceding conversion was documented for MA progressors. Converters to MNV presented an accelerated thinning of the choroid and appearance changes in the choroid prior to MNV onset. The large-scale automated image analysis allowed us to distinctly assess the progression of morphologic changes in intermediate AMD based on conventional OCT imaging. Distinct topographic and temporal patterns allow to prospectively determine eyes with risk of progression and thereby greatly improving early detection, prevention and development of novel therapeutic strategies.
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- 2021
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25. Association of macular perfusion status with microvascular parameters up to the far periphery in diabetic retinopathy using multimodal imaging
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Dorottya Hajdu, Aleksandra Sedova, Felix Datlinger, Julia Hafner, Irene Steiner, Katharina Kriechbaum, Christoph Scholda, Stefan Sacu, Ursula Schmidt-Erfurth, and Andreas Pollreisz
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Diabetic retinopathy ,Retinal ischemia ,SSOCTA ,UWF ,FA ,DR severity ,Ophthalmology ,RE1-994 - Abstract
Abstract Background The aim of our study was to investigate a possible association between macular perfusion status and retinal ischemia and leakage up to far peripheral retinal areas in eyes with early to advanced stages of diabetic retinopathy (DR). Methods In a retrospective, cross sectional analysis ultrawide field (UWF) color fundus photos (Optos, Optomap California) were graded for DR severity. Foveal avascular zone (FAZ) and vessel density from the superficial (SCP) and deep capillary plexus (DCP) were assessed on optical coherence tomography angiography (OCTA) scans (Topcon, DRI-OCT Triton). UWF angiography images were used to quantify leakage/ischemic index and number of microaneurysms (MA). Age, gender, disease duration, type of diabetes, HbA1C, hypertension, complications of diabetes and ocular history were recorded. Univariate mixed models and Spearman correlation analysis were used for statistical testing. Results 24 eyes of 17 laser-naive diabetic patients with different stages of DR were analyzed. The mean age was 59.56 ± 8.46 years and the mean disease duration 19.65 ± 12.25 years. No statistically significant associations between FAZ size, macular vessel density of SCP/DCP and peripheral retinal ischemia, leakage and MA number were demonstrated. Higher stages of DR were associated with ischemic index (estimate [95% CI]: 13.04 [1.5; 24.5], p = 0.033) and MA count (estimate [95% CI]: 43.7 [15.6; 71.8], p = 0.01), but no association with leakage index was observed. Only weak correlations between DR severity and anamnestic data were found. Conclusion Retinal ischemic index and the amount of MAs assessed on UWFA up to peripheral areas are indicators of DR severity but not related to microvascular perfusion status in the macular region. Significance and timely sequence of macular vessel density in DR progression may need to be re-evaluated in future studies.
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- 2020
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26. Quantitative assessment of retinal fluid in neovascular age-related macular degeneration under anti-VEGF therapy
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Gregor S. Reiter and Ursula Schmidt-Erfurth
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Ophthalmology ,RE1-994 - Abstract
The retinal world has been revolutionized by optical coherence tomography (OCT) and anti-vascular endothelial growth factor (VEGF) therapy. The numbers of intravitreal injections are on a constant rise and management in neovascular age-related macular degeneration (nAMD) is mainly driven by the qualitative assessment of macular fluid as detected on OCT scans. The presence of macular fluid, particularly subretinal fluid (SRF) and intraretinal fluid (IRF), has been used to trigger re-treatments in clinical trials and the real world. However, large discrepancies can be found between the evaluations of different readers or experts and especially small amounts of macular fluid might be missed during this process. Pixel-wise detection of macular fluid uses an entire OCT volume to calculate exact volumes of retinal fluid. While manual annotations of such pixel-wise fluid detection are unfeasible in a clinical setting, artificial intelligence (AI) is able to overcome this hurdle by providing real-time results of macular fluid in different retinal compartments. Quantitative fluid assessments have been used for various post hoc analyses of randomized controlled trials, providing novel insights into anti-VEGF treatment regimens. Nonetheless, the application of AI-algorithms in a prospective patient care setting is still limited. In this review, we discuss the use of quantitative fluid assessment in nAMD during anti-VEGF therapy and provide an outlook to novel forms of patient care with the support of AI quantifications.
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- 2022
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27. Retinal oxygen saturation, vessel diameter and flicker response in eyes with specific subtypes of neovascular age-related macular degeneration during aflibercept treatment.
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Stefan Sacu, Katharina Eibenberger, Doreen Schmidl, Sandra Rezar-Dreindl, Gerhard Garhöfer, Jonas Brugger, Wolf Buehl, Leopold Schmetterer, and Ursula Schmidt-Erfurth
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Medicine ,Science - Abstract
PurposeTo evaluate the effect of intravitreal aflibercept monotherapy on arterial and venous oxygen saturation, retinal vessel diameter and flicker response in patients with newly diagnosed specific subtypes of exudative maculopathy.MethodsThis prospective study included forty-four eyes of 44 patients with treatment-naïve polypoidal choroidal vasculopathy (PCV, n = 12), hemorrhagic choroidal neovascularization (hCNV, n = 12), pigment epithelium detachment (PED, n = 9) and type 3 MNV (RAP, n = 11). All patients received three initial aflibercept 2mg/0.05ml injections (Eylea®) in monthly intervals (loading phase) and were subsequently treated until month 12. Measurements of arterial and venous oxygen saturation, vessel diameters and flicker response were performed using the Dynamic Vessel Analyzer (DVA; IMEDOS, Jena, Germany). Statistical analysis was performed on the total population at baseline, after loading dose and at the last follow-up visit.ResultsThe arterial oxygen saturation was 94.01±2.14% and showed no change after loading dose (93.94±2.88%, p = 0.4; estimated difference [confidence interval] -0.38 [-1.24; 0.48]) and at the last visit (95.48±1.90%; p = 0.1; -1.29 [-0.34; 2.91]). The venous oxygenation during treatment was 78.49±6.93% at baseline, 80.94±7.71% after 3-monthly injections (p = 0.7; -0.43 [-2.72; 1.86]) and 80.56±7.33% at month 12 (p = 0.5; 1.07 [-2.10; 4.24). The arterial and venous vessel diameters were 94±22μm and 131±19μm at baseline, and remained unchanged following aflibercept loading dose and at the last follow-up visit (p-value: p = 0.5; 2.30 [-5.00; 9.59] p = 0.8; 0.59 [-3.17; 4.34]). During stimulation with flicker light, arterial diameter changed by +1.24±4.93% at baseline and remained stable at month 3 (+2.70±5.95%; p = 0.5; 1.43 [-2.54; 5.41]) while the change in venous diameter during flicker stimulation was +4.52±4.45% at baseline and +4.13±3.65% after loading dose (p = 0.4, 5.18 [1.73; 8.63]).ConclusionDuring intravitreal aflibercept treatment oxygen saturation, vessel diameter and flicker response did not change in the total population of patients with specific subtypes of exudative maculopathy.
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- 2022
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28. Association of microvascular biomarkers in fluorescein angiography with macrovascular-related mortality in clinical routine data.
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Felix Goldbach, Georgios Mylonas, Martin Riegelnegg, Jonas Brugger, Ursula Schmidt-Erfurth, and Bianca S Gerendas
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Medicine ,Science - Abstract
PurposeEarly detection of microvascular changes in the retina may be important for the risk assessment of cardiovascular health. Therefore, the purpose of this study was to investigate imaging biomarkers in fluorescein angiography (FA) as potential predictors for cardiovascular mortality.MethodsIn this retrospective, matched case-control study, we included FA images from clinical routine data between 2007 and 2018 of 100 patients who died of macrovascular events (Group 1) and 100 age- and sex-matched controls (Group 2). All patients were under treatment for different, mostly retinal, ocular diseases. FA images were used for the measurement of the foveal avascular zone (FAZ) and the arteriolar and venular caliber.ResultsPatients mean age on examination day was 69.5 ± 8.3 years with a 1:1 female:male subject ratio. Mean FAZ area of our sample was 0.340 ± 0.135 mm2 for Group 1 and 0.264 ± 0.137 mm2 for Group 2 (P < 0.001), showing a larger FAZ area in patients who subsequently died of macrovascular-related systemic diseases.ConclusionsIndividuals effected by a macrovascular-related disease show a larger FAZ on FA examinations before the event compared to patients which are unaffected. Our results highlight a possible role of the FAZ as additional biomarker for the cardiovascular condition.
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- 2022
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29. Combining stimulus types for improved coverage in population receptive field mapping
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David Linhardt, Maximilian Pawloff, Allan Hummer, Michael Woletz, Martin Tik, Markus Ritter, Ursula Schmidt-Erfurth, and Christian Windischberger
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fMRI ,Retinotopy ,pRF mapping ,Coverage map ,Visual stimuli ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Retinotopy experiments using population receptive field (pRF) mapping are ideal for assigning regions in the visual field to cortical brain areas. While various designs for visual stimulation were suggested in the literature, all have specific shortcomings regarding visual field coverage. Here we acquired high-resolution 7 Tesla fMRI data to compare pRF-based coverage maps obtained with the two most commonly used stimulus variants: moving bars; rotating wedges and expanding rings. We find that stimulus selection biases the spatial distribution of pRF centres. In addition, eccentricity values and pRF sizes obtained from wedge/ring or bar stimulation runs show systematic differences. Wedge/ring stimulation results show lower eccentricity values and strongly reduced pRF sizes compared to bar stimulation runs. Statistical comparison shows significantly higher pRF centre numbers in the foveal 2° region of the visual field for wedge/ring compared to bar stimuli. We suggest and evaluate approaches for combining pRF data from different visual stimulus patterns to obtain improved mapping results.
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- 2021
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30. Incidence and surgical care of retinal detachment during the first SARS-CoV-2 lockdown period at a tertiary referral center in Austria.
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Markus Schranz, Michael Georgopoulos, Stefan Sacu, Adrian Reumueller, Gregor S Reiter, Georgios Mylonas, Ursula Schmidt-Erfurth, and Andreas Pollreisz
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Medicine ,Science - Abstract
PurposeTo assess the influence of the SARS-CoV-2 lockdown in spring on frequency, severity and quality of care of rhegmatogeneous retinal detachments (RRD) in a tertiary referral center in Vienna, Austria.MethodsSingle center, consecutive case series with historical controls. Patients presenting with primary RRD during the first Austrian SARS-CoV-2 lockdown (March 16th-May 3rd 2020) and a corresponding control group consisting of the same time period of the preceding 3 years.ResultsThe mean number of patients with RD in the reference group (RG) was 22 (± 1) and in the lockdown group (LG) 15. Median total delay, defined as onset of symptoms until surgery, in the RG was 5 (lower quartile: 3.0; upper quartile: 8.0) compared to 7 (3.0; 12.0) days in the LG, (p = 0.740). During the lockdown 67% of patients were referred from an external ophthalmologist compared to 52% in the RG, (p = 0.395). 34% of patients in the RG presented with an attached macula compared to 33% in the LG (p = 0.597). PVR was present in 49% of cases in the RG compared to 73% in the LG. Single surgery success (SSS) rates were lower in the LG (73.3%) compared to the RG (85.3%), (p = 0.275).ConclusionPatients with RRD during the SARS-CoV-2 lockdown presented and were treated within acceptable time limits, showed the same macula-on ratios but a higher PVR rate and a tendency towards worse SSS rates compared to the time period of the preceding 3 years.
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- 2021
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31. Three-dimensional composition of the photoreceptor cone layers in healthy eyes using adaptive-optics optical coherence tomography (AO-OCT).
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Adrian Reumueller, Lorenz Wassermann, Matthias Salas, Markus Schranz, Valentin Hacker, Georgios Mylonas, Stefan Sacu, Wolfgang Drexler, Michael Pircher, Ursula Schmidt-Erfurth, and Andreas Pollreisz
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Medicine ,Science - Abstract
PurposeTo assess the signal composition of cone photoreceptors three-dimensionally in healthy retinas using adaptive optics optical coherence tomography (AO-OCT).MethodsStudy population. Twenty healthy eyes of ten subjects (age 23 to 67). Procedures. After routine ophthalmological assessments, eyes were examined using AO-OCT. Three-dimensional volumes were acquired at 2.5° and 6.5° foveal eccentricity in four main meridians (superior, nasal, inferior, temporal). Cone densities and signal compositions were investigated in four different planes: the cone inner segment outer segment junction (IS/OS), the cone outer segment combined with the IS/OS (ISOS+), the cone outer segment tips (COST) and full en-face plane (FEF) combining signals from all mentioned cone layers. Additionally, reliability of a simple semi-automated approach for assessment of cone density was tested. Main outcome measures. Cone density of IS/OS, IS/OS+, COST and FEF. Qualitative depiction and composition of each cone layer. Inter-rater agreement of cone density measurements.ResultsMean overall cone density at all eccentricities was highest at the FEF plane (21.160/mm2), followed by COST (20.450/mm2), IS/OS+ (19.920/mm2) and IS/OS (19.530/mm2). The different meridians and eccentricities had a significant impact on cone density, with lower eccentricity resulting in higher cone densities (p≤.001), which were highest at the nasal, then temporal, then inferior and then superior meridian. Depiction of the cone mosaic differed between all 4 layers regarding signal size and packing density. Therefore, different cone layers showed evident but not complete signal overlap. Using the semi-automated technique for counting of cone signals achieved high inter-rater reliability (ICC > .99).ConclusionsIn healthy individuals qualitative and quantitative changes in cone signals are found not only in different eccentricities and meridians, but also within different photoreceptor layers. The variation between cone planes has to be considered when assessing the integrity of cone photoreceptors in healthy and diseased eyes using adaptive optics technology.
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- 2021
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32. Comparison of safety and effectiveness between 23-gauge and 25-gauge vitrectomy surgery in common vitreoretinal diseases.
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Aleksandra Sedova, Irene Steiner, Rene Peter Matzenberger, Michael Georgopoulos, Christoph Scholda, Katharina Franziska Kriechbaum, Claudette Abela-Formanek, Georgios Mylonas, Stefan Sacu, Ursula Schmidt-Erfurth, and Andreas Pollreisz
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Medicine ,Science - Abstract
PurposeTo assess and compare safety and effectiveness between 23-gauge and 25-gauge vitrectomy systems for the treatment of common vitreoretinal diseases in non-vitrectomized eyes.MethodsRetrospective evaluation of patients who underwent pars plana vitrectomy from April 2018 to December 2019 at the Department of Ophthalmology and Optometry at the Medical University of Vienna (MUV) for the following indications: macular epiretinal membrane, macular hole, macular lamellar hole, vitreous hemorrhage, vitreous opacities, vitreomacular traction syndrome and macular edema.Results201 eyes of 195 patients that underwent 23-gauge (n = 105 eyes) or 25-gauge (n = 96 eyes) vitrectomy were included in this study. The mean best-corrected visual acuity (BCVA) improved at 1-3 months postoperatively and beyond 3 months in both gauge groups. Risk of any complication within 1 month postoperatively was lower in the 25-gauge group, but the difference was statistically not significant (HR [95% CI]: 0.95 [0.53; 1.70], p = 0.85). Intraocular pressure less than 5 mmHg was observed in 2 eyes (2%) in the 23-gauge group at the first postoperative day. Intraocular pressure elevation over 25 mmHg occurred in 5 eyes (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group) at postoperative day 1, between 7 and 28 days in 5 cases (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group), and in 2 eyes (2%) of the 23-gauge group at postoperative day 145 and 61, respectively. Retinal detachment occurred in 1 eye (1%) in the 23-gauge and in 3 eyes (3%) in the 25-gauge group. We did not observe any cases of endophthalmitis.ConclusionResults in terms of safety, surgical success and visual outcomes for the treatment of common vitreoretinal surgery indications seem to be comparable between 23-gauge and 25-gauge vitrectomy systems, indicating that the two gauge systems can be used equally in the clinical routine.
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- 2021
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33. Impact of large choroidal vessels on choriocapillaris flow deficit analyses in optical coherence tomography angiography.
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Valentin Hacker, Gregor Sebastian Reiter, Markus Schranz, Reinhard Told, Adrian Reumüller, Dominik Hofer, Irene Steiner, Ursula Schmidt-Erfurth, and Stefan Sacu
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Medicine ,Science - Abstract
PurposeTo investigate the impact of large choroidal vessels (LCV) on Choriocapillaris (CC) flow deficit (FD) analyses with swept-source optical coherence tomography angiography (SS-OCTA).DesignProspective, cross-sectional study.MethodsMacular 6x6mm SS-OCTA scans were obtained from intermediate age-related macular degeneration (iAMD) and healthy eyes. Images were captured and processed according to most common standards and analyzed for percentage of flow-deficits (FD%) within four 1x1mm squares at the corners of each image. Choroidal thickness (CT), iris color and refraction error were considered as potential influential factors for LCV visibility. A linear mixed model and logistic regression models were calculated for statistical evaluation.ResultsSixty-nine iAMD and 49 age-matched healthy eyes were enrolled. LCV were visible in at least one sector in 52% of iAMD and 47% of healthy eyes. Within the iAMD group FD% were significantly lower in areas containing LCV (p = 0.0029). Increasing CT resulted in an odds ratio decrease of LCV (OR: 0.94, pConclusionsLCV can significantly affect CC FD analyses of SS-OCTA images. Their visibility is negatively associated with CT. The impact of LCV should be taken into account when performing CC FD assessments, especially in patients where reduced CT is to be expected and inclusion of affected areas should be considered carefully.
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- 2021
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34. Effectiveness and safety of ranibizumab 0.5 mg in treatment-naïve patients with diabetic macular edema: Results from the real-world global LUMINOUS study.
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Paul Mitchell, Tom G Sheidow, Michel E Farah, Sajjad Mahmood, Angelo M Minnella, Nicole Eter, Bora Eldem, Hassan Al-Dhibi, Wayne Macfadden, Soumil Parikh, Cornelia Dunger-Baldauf, Mohamed M Mahgoub, Ursula Schmidt-Erfurth, and LUMINOUS study investigators
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Medicine ,Science - Abstract
PURPOSE:To assess the one-year effectiveness and safety of ranibizumab 0.5 mg in treatment- naïve patients with diabetic macular edema (DME) enrolled in the real-world LUMINOUS study. PATIENTS AND METHODS:A 5-year, prospective, observational, open-label, global study which recruited 30,138 patients across all approved indications. Consenting patients (≥18 years) who were treatment-naïve or previously treated with ranibizumab or other ocular treatments were treated as per the local ranibizumab label. Here, we present the change in visual acuity (VA) (Early Treatment Diabetic Retinopathy Study letter score; primary treated eye) at Year 1, as well as the change in VA based on injection frequencies (≤4 and ≥5), treatment exposure, and the overall adverse events (AEs) and serious AEs (SAEs) in treatment-naïve DME patients. RESULTS:Of the 4,710 DME patients enrolled in the study, 1,063 were treatment-naïve. At baseline, mean age was 64.5 years, 54.7% were male, and 69.2% were white. At 1 year, mean VA letter score improved by +3.5 (n = 502) from a baseline of 57.7 with a mean of 4.5 injections. Presented by injection frequencies ≤4 and ≥5, VA letter score gains were 0.5 (n = 264) and 6.9 (n = 238) from baseline letter scores of 56.6 and 59.0, respectively. Over 5 years, the incidence of ocular/non-ocular AEs and SAEs was 7.2%/10.1% and 0.3%/5.8%, respectively. No endophthalmitis cases were reported. CONCLUSIONS:The LUMINOUS study included patients with DME with more diverse baseline characteristics than those in randomized clinical trials. The 1-year data showed improvement in VA with low number of injections in treatment- naïve patients with DME. Greater VA gains were observed in patients who received ≥5 injections. No new safety findings were identified. LUMINOUS confirms the effectiveness and safety of ranibizumab for the treatment of patients with DME in a real-world clinical practice.
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- 2020
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35. Identification of microvascular and morphological alterations in eyes with central retinal non-perfusion.
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Dorottya Hajdu, Reinhard Told, Orsolya Angeli, Guenther Weigert, Andreas Pollreisz, Ursula Schmidt-Erfurth, and Stefan Sacu
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Medicine ,Science - Abstract
PurposeTo evaluate the characteristics and morphological alterations in central retinal ischemia caused by diabetic retinopathy (DR) or retinal vein occlusion (RVO) as seen in optical coherence tomography angiography (OCTA) and their relationship to visual acuity.MethodsSwept-source optical coherence tomography (SSOCT) and OCTA (Topcon, Triton) data of patients with central involving retinal ischemia were analyzed in this cross-sectional study. The following parameters were evaluated: vessel parameters, foveal avascular zone (FAZ), intraretinal cysts (IRC), microaneurysms (MA), vascular collaterals in the superficial (SCP) and deep plexuses (DCP), hyperreflective foci (HRF), epiretinal membrane (ERM), external limiting membrane (ELM) and ellipsoid zone (EZ) disruption, as well as the disorganization of retinal inner layers (DRIL). Best-corrected visual acuity (BCVA), age, gender, disease duration and ocular history were also recorded.Results44 eyes of 44 patients (22 with RVO, 22 with DR) were analyzed. The mean age was 60.55 ± 11.38 years and mean BCVA 0.86 ± 0.36 (Snellen, 6m). No significant difference was found between DR subgroups (non proliferative vs. proliferative). Between RVO subgroups (CRVO vs. BRVO) a significant difference was found in term of collateral vessel of the DCP (p = 0.014). A pooled DR and RVO group were created and compared. Significantly more MAs (p = 0.007) and ERM (p = 0.007) were found in the DR group. Statistically significant negative correlation was demonstrated between FAZ and BCVA (p = 0.45) when analyzing all patients with retinal ischemia.ConclusionThis study has shown that the best predictor of visual outcome in center involved ischemic diseases is the size of FAZ. Besides the presence of MAs and ERM, all other OCT and OCTA parameters were present in a similar extent in DR and RVO group despite the completely different disease origins. Our results suggest that as soon as retinal ischemia in the macular region is present, it has a similar appearance and visual outcome independently of the underlying disease.
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- 2020
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36. Intraretinal microvascular changes after ERM and ILM peeling using SSOCTA.
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Reinhard Told, Michael Georgopoulos, Gregor Sebastian Reiter, Lorenz Wassermann, Leyla Aliyeva, Lukas Baumann, Claudette Abela-Formanek, Andreas Pollreisz, Ursula Schmidt-Erfurth, and Stefan Sacu
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Medicine ,Science - Abstract
BackgroundTo prospectively investigate retinal vascular changes in patients undergoing epiretinal membrane (ERM) and internal limiting membrane (ILM) peeling using swept source optical coherence tomography angiography (SSOCTA).MethodsConsecutive patients were grouped based on ERM severity and followed using SSOCTA up to month 3 after surgical intervention. Superficial and deep foveal avascular zone (s/dFAZ) as well as foveal and parafoveal vessel density (VD) were correlated with ERM severity and visual acuity. Differences between groups were evaluated.ResultsSignificant correlations were found between ERM severity and baseline sFAZ, dFAZ and best corrected visual acuity (BCVA), central retinal subfield thickness (CST) and ΔCST (r = -0.52, r = -0.43, r = -0.42, r = 0.58, r = 0.39; all p0.05).ConclusionsThis study clearly shows that ERM severity based on ERM staging has to be taken into account when undertaking studies in patients with idiopathic ERM using SSOCTA. Further, specific changes in the superficial and deep retinal vasculature in eyes undergoing ERM and ILM peeling were found. However, the clinical usefulness and prognostic value for post-surgical treatment BCVA of the SSOCTA-derived variables (sFAZ and dFAZ area, as well as foveal and parafoveal VD) used remains questionable.
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- 2020
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37. Evaluating the impact of vitreomacular adhesion on anti-VEGF therapy for retinal vein occlusion using machine learning
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Sebastian M. Waldstein, Alessio Montuoro, Dominika Podkowinski, Ana-Maria Philip, Bianca S. Gerendas, Hrvoje Bogunovic, and Ursula Schmidt-Erfurth
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Medicine ,Science - Abstract
Abstract Vitreomacular adhesion (VMA) represents a prognostic biomarker in the management of exudative macular disease using anti-vascular endothelial growth factor (VEGF) agents. However, manual evaluation of VMA in 3D optical coherence tomography (OCT) is laborious and data on its impact on therapy of retinal vein occlusion (RVO) are limited. The aim of this study was to (1) develop a fully automated segmentation algorithm for the posterior vitreous boundary and (2) to study the effect of VMA on anti-VEGF therapy for RVO. A combined machine learning/graph cut segmentation algorithm for the posterior vitreous boundary was designed and evaluated. 391 patients with central/branch RVO under standardized ranibizumab treatment for 6/12 months were included in a systematic post-hoc analysis. VMA (70%) was automatically differentiated from non-VMA (30%) using the developed method combined with unsupervised clustering. In this proof-of-principle study, eyes with VMA showed larger BCVA gains than non-VMA eyes (BRVO: 15 ± 12 vs. 11 ± 11 letters, p = 0.02; CRVO: 18 ± 14 vs. 9 ± 13 letters, p
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- 2017
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38. Axon numbers and landmarks of trigeminal donor nerves for corneal neurotization.
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Eva Györi, Chieh-Han John Tzou, Wolfgang J Weninger, Lukas Reissig, Ursula Schmidt-Erfurth, Christine Radtke, and Roman Dunavoelgyi
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Medicine ,Science - Abstract
PURPOSE:Corneal anesthesia leads to chronic corneal injury. This anatomical study characterizes the donor nerve branches of the supratrochlear and supraorbital nerves used for corneal neurotization. METHODS:In 13 non-embalmed cadavers, the supratrochlear and supraorbital nerves were dissected and distances to anatomical landmarks measured. Cross-sections of supratrochlear and supraorbital donor nerves were harvested and histomorphometrically analyzed to assess the number of myelinated axons. RESULTS:The donor axon counts were 3146 ± 1069.9 for the supratrochlear and 1882 ± 903 for the supraorbital nerve distal to the supraorbital notch. The supratrochlear nerve was dissected on the medial upper eyelid 2 cm lateral to the facial midline and the branch of the supraorbital nerve 1 cm medial to the mid-pupillary line. CONCLUSION:The supraorbital and supratrochlear branches of the trigeminal nerve are potent donor nerves for corneal neurotization in the treatment of neuropathic keratopathy and can be reliably dissected using anatomical landmarks.
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- 2018
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39. Choroidal Neovascularization Induced by Immunogenic Alteration of the Retinal Pigment Epithelium in Dengue Fever
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Carlos Eduardo Veloso, Ursula Schmidt-Erfurth, and Márcio B. Nehemy
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Choroidal neovascularization ,Complement activation ,Antiangiogenic therapy ,Dengue maculopathy ,Ophthalmology ,RE1-994 - Abstract
Purpose: To report the first case of choroidal neovascularization (CNV) secondary to dengue fever. Case Report: A 54-year-old female was referred to our department with blurred vision and metamorphopsia in her left eye. Two weeks earlier, she had presented all of the classic symptoms of dengue fever including a positive serology. Her best-corrected visual acuity (BCVA) was 20/150 in the left eye. She underwent a fundus examination, fluorescein angiography (FA) and spectral domain optical coherence tomography. Results: All findings were consistent with CNV secondary to dengue fever. FA revealed a classic CNV associated with focal retinal pigment epithelium (RPE) destruction and detachment. Three consecutive monthly injections of intravitreal ranibizumab resulted in functional and anatomical improvement for as long as 6 months with a BCVA of 20/25. However, CNV recurred 2 years later, again with an improvement after ranibizumab therapy, but with persistence of a fibrovascular RPE detachment, highlighting the pathomechanism of a classic CNV formation. Conclusions: Maculopathy in dengue fever may be followed by CNV as a result of the immunologic alteration of the RPE. Physicians should be aware of this manifestation to be able to initiate adequate treatment with excellent functional and anatomical results.
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- 2015
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40. Impact of B-Scan Averaging on Spectralis Optical Coherence Tomography Image Quality before and after Cataract Surgery
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Dominika Podkowinski, Ehsan Sharian Varnousfaderani, Christian Simader, Hrvoje Bogunovic, Ana-Maria Philip, Bianca S. Gerendas, Ursula Schmidt-Erfurth, and Sebastian M. Waldstein
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Ophthalmology ,RE1-994 - Abstract
Background and Objective. To determine optimal image averaging settings for Spectralis optical coherence tomography (OCT) in patients with and without cataract. Study Design/Material and Methods. In a prospective study, the eyes were imaged before and after cataract surgery using seven different image averaging settings. Image quality was quantitatively evaluated using signal-to-noise ratio, distinction between retinal layer image intensity distributions, and retinal layer segmentation performance. Measures were compared pre- and postoperatively across different degrees of averaging. Results. 13 eyes of 13 patients were included and 1092 layer boundaries analyzed. Preoperatively, increasing image averaging led to a logarithmic growth in all image quality measures up to 96 frames. Postoperatively, increasing averaging beyond 16 images resulted in a plateau without further benefits to image quality. Averaging 16 frames postoperatively provided comparable image quality to 96 frames preoperatively. Conclusion. In patients with clear media, averaging 16 images provided optimal signal quality. A further increase in averaging was only beneficial in the eyes with senile cataract. However, prolonged acquisition time and possible loss of details have to be taken into account.
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- 2017
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41. Autophagy mediates cell cycle response by regulating nucleocytoplasmic transport of PAX6 in limbal stem cells under ultraviolet-A stress.
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Maria Laggner, Andreas Pollreisz, Gerald Schmidinger, Ursula Schmidt-Erfurth, and Ying-Ting Chen
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Medicine ,Science - Abstract
Limbal stem cells (LSC) account for homeostasis and regeneration of corneal epithelium. Solar ultraviolet A (UVA) is the major source causing oxidative damage in the ocular surface. Autophagy, a lysosomal degradation mechanism, is essential for physiologic function and stress defense of stem cells. PAX6, a master transcription factor governing corneal homeostasis by regulating cell cycle and cell fate of LSC, responds to oxidative stress by nucleocytoplasmic shuttling. Impaired autophagy and deregulated PAX6 have been reported in oxidative stress-related ocular surface disorders. We hypothesize a functional role for autophagy and PAX6 in LSC's stress response to UVA. Therefore, human LSC colonies were irradiated with a sub-lethal dose of UVA and autophagic activity and intracellular reactive oxygen species (ROS) were measured by CYTO-ID assay and CM-H2DCFDA live staining, respectively. Following UVA irradiation, the percentage of autophagic cells significantly increased in LSC colonies while intracellular ROS levels remained unaffected. siRNA-mediated knockdown (KD) of ATG7 abolished UVA-induced autophagy and led to an excessive accumulation of ROS. Upon UVA exposure, LSCs displayed nuclear-to-cytoplasmic translocation of PAX6, while ATG7KD or antioxidant pretreatment largely attenuated the intracellular trafficking event. Immunofluorescence showing downregulation of proliferative marker PCNA and induction of cell cycle regulator p21 indicates cell cycle arrest in UVA-irradiated LSC. Abolishing autophagy, adenoviral-assisted restoration of nuclear PAX6 or antioxidant pretreatment abrogated the UVA-induced cell cycle arrest. Adenoviral expression of an ectopic PAX gene, PAX7, did not affect UVA cell cycle response. Furthermore, knocking down PAX6 attenuated the cell cycle progression of irradiated ATG7KD LSC by de-repressing p21 expression. Collectively, our data suggest a crosstalk between autophagy and PAX6 in regulating cell cycle response of ocular progenitors under UVA stress. Autophagy deficiency leads to impaired intracellular trafficking of PAX6, perturbed redox balance and uncurbed cell cycle progression in UVA-stressed LSCs. The coupling of autophagic machinery and PAX6 in cell cycle regulation represents an attractive therapeutic target for hyperproliferative ocular surface disorders associated with solar radiation.
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- 2017
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42. Tyrosinase-Cre-Mediated Deletion of the Autophagy Gene Atg7 Leads to Accumulation of the RPE65 Variant M450 in the Retinal Pigment Epithelium of C57BL/6 Mice.
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Supawadee Sukseree, Ying-Ting Chen, Maria Laggner, Florian Gruber, Valérie Petit, Ionela-Mariana Nagelreiter, Veronika Mlitz, Heidemarie Rossiter, Andreas Pollreisz, Ursula Schmidt-Erfurth, Lionel Larue, Erwin Tschachler, and Leopold Eckhart
- Subjects
Medicine ,Science - Abstract
Targeted gene knockout mouse models have helped to identify roles of autophagy in many tissues. Here, we investigated the retinal pigment epithelium (RPE) of Atg7f/f Tyr-Cre mice (on a C57BL/6 background), in which Cre recombinase is expressed under the control of the tyrosinase promoter to delete the autophagy gene Atg7. In line with pigment cell-directed blockade of autophagy, the RPE and the melanocytes of the choroid showed strong accumulation of the autophagy adaptor and substrate, sequestosome 1 (Sqstm1)/p62, relative to the levels in control mice. Immunofluorescence and Western blot analysis demonstrated that the RPE, but not the choroid melanocytes, of Atg7f/f Tyr-Cre mice also had strongly increased levels of retinoid isomerohydrolase RPE65, a pivotal enzyme for the maintenance of visual perception. In contrast to Sqstm1, genes involved in retinal regeneration, i.e. Lrat, Rdh5, Rgr, and Rpe65, were expressed at higher mRNA levels. Sequencing of the Rpe65 gene showed that Atg7f/f and Atg7f/f Tyr-Cre mice carry a point mutation (L450M) that is characteristic for the C57BL/6 mouse strain and reportedly causes enhanced degradation of the RPE65 protein by an as-yet unknown mechanism. These results suggest that the increased abundance of RPE65 M450 in the RPE of Atg7f/f Tyr-Cre mice is, at least partly, mediated by upregulation of Rpe65 transcription; however, our data are also compatible with the hypothesis that the RPE65 M450 protein is degraded by Atg7-dependent autophagy in Atg7f/f mice. Further studies in mice of different genetic backgrounds are necessary to determine the relative contributions of these mechanisms.
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- 2016
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43. Automated Fovea Detection in Spectral Domain Optical Coherence Tomography Scans of Exudative Macular Disease
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Jing Wu, Sebastian M. Waldstein, Alessio Montuoro, Bianca S. Gerendas, Georg Langs, and Ursula Schmidt-Erfurth
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Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Medical technology ,R855-855.5 - Abstract
In macular spectral domain optical coherence tomography (SD-OCT) volumes, detection of the foveal center is required for accurate and reproducible follow-up studies, structure function correlation, and measurement grid positioning. However, disease can cause severe obscuring or deformation of the fovea, thus presenting a major challenge in automated detection. We propose a fully automated fovea detection algorithm to extract the fovea position in SD-OCT volumes of eyes with exudative maculopathy. The fovea is classified into 3 main appearances to both specify the detection algorithm used and reduce computational complexity. Based on foveal type classification, the fovea position is computed based on retinal nerve fiber layer thickness. Mean absolute distance between system and clinical expert annotated fovea positions from a dataset comprised of 240 SD-OCT volumes was 162.3 µm in cystoid macular edema and 262 µm in nAMD. The presented method has cross-vendor functionality, while demonstrating accurate and reliable performance close to typical expert interobserver agreement. The automatically detected fovea positions may be used as landmarks for intra- and cross-patient registration and to create a joint reference frame for extraction of spatiotemporal features in “big data.” Furthermore, reliable analyses of retinal thickness, as well as retinal structure function correlation, may be facilitated.
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- 2016
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44. Learning Temporally Equivariance for Degenerative Disease Progression in OCT by Predicting Future Representations.
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Taha Emre, Arunava Chakravarty, Dmitry A. Lachinov, Antoine Rivail, Ursula Schmidt-Erfurth, and Hrvoje Bogunovic
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- 2024
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45. Forecasting Disease Progression with Parallel Hyperplanes in Longitudinal Retinal OCT.
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Arunava Chakravarty, Taha Emre, Dmitry A. Lachinov, Antoine Rivail, Hendrik P. N. Scholl, Lars Fritsche, Sobha Sivaprasad, Daniel Rueckert, Andrew J. Lotery, Ursula Schmidt-Erfurth, and Hrvoje Bogunovic
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- 2024
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46. Spatiotemporal Representation Learning for Short and Long Medical Image Time Series.
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Chengzhi Shen, Martin J. Menten, Hrvoje Bogunovic, Ursula Schmidt-Erfurth, Hendrik P. N. Scholl, Sobha Sivaprasad, Andrew J. Lotery, Daniel Rueckert, Paul Hager, and Robbie Holland
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- 2024
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47. Improving Clinical Predictions with Multi-Modal Pre-training in Retinal Imaging.
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Emese Sükei, Elisabeth Rumetshofer, Niklas Schmidinger, Andreas Mayr, Ursula Schmidt-Erfurth, Günter Klambauer, and Hrvoje Bogunovic
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- 2024
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48. Morph-SSL: Self-Supervision With Longitudinal Morphing for Forecasting AMD Progression From OCT Volumes.
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Arunava Chakravarty, Taha Emre, Oliver Leingang, Sophie Riedl, Julia Mai, Hendrik P. N. Scholl, Sobha Sivaprasad, Daniel Rueckert, Andrew J. Lotery, Ursula Schmidt-Erfurth, and Hrvoje Bogunovic
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- 2024
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49. 3DTINC: Time-Equivariant Non-Contrastive Learning for Predicting Disease Progression From Longitudinal OCTs.
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Taha Emre, Arunava Chakravarty, Antoine Rivail, Dmitry A. Lachinov, Oliver Leingang, Sophie Riedl, Julia Mai, Hendrik P. N. Scholl, Sobha Sivaprasad, Daniel Rueckert, Andrew J. Lotery, Ursula Schmidt-Erfurth, and Hrvoje Bogunovic
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- 2024
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50. Learning Spatio-Temporal Model of Disease Progression With NeuralODEs From Longitudinal Volumetric Data.
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Dmitrii A. Lachinov, Arunava Chakravarty, Christoph Grechenig, Ursula Schmidt-Erfurth, and Hrvoje Bogunovic
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- 2024
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