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Kortuem FC, Merle DA, Reith M, Kuehlewein L, Jung R, Holocher S, Stingl K, Stingl K, Kempf M. Defining reference values of arterioles in healthy individuals for studies with adaptive optics imaging. FRONTIERS IN OPHTHALMOLOGY 2024; 4:1348900. [PMID: 38984139 PMCID: PMC11182109 DOI: 10.3389/fopht.2024.1348900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 02/15/2024] [Indexed: 07/11/2024]
Abstract
Purpose To investigate age-dependent wall to lumen ratio (WLR) reference values for healthy individuals in adaptive optics imaging (AO). WLR serves as an objective, dimensionless parameter for the evaluation of structural changes in vessels caused by conditions like arterial hypertension, diabetes or vascular stenosis. Methods 50 right eyes of healthy individuals were examined by adaptive optics imaging. The central big arterioles and smaller arterial branches at least one disc diameter away from the optic disc, approximately above or below the macula were measured by the manufacturer's software. The wall-lumen-ratio (WLR), the wall cross-sectional area (WCSA) and lumen diameter (LD) were assessed. Subsequent data analysis was performed with a focus on variables including age, gender and blood pressure. Results Normative values for WLR, WCSA and LD in 5 different age groups could be established. However, no significant differences between the age groups were found. Intra-subject comparisons revealed significantly higher WLRs on peripheral branches when compared to central arterioles. WLR showed in this normotensive cohort no relevant correlation with the systolic, diastolic and mean blood pressure. Gender and intraocular pressure had no influence on the vascular parameters. Conclusion AO is capable of examining vascular alterations in arterioles at an almost microscopic level. Age did not seem to alter WLR, normotensive blood pressure parameters showed also no significant impact. AO-based vessel analysis may provide clinically useful biomarkers for cardiovascular health and should be tested in future studies.
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Affiliation(s)
- Friederike C Kortuem
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - David A Merle
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
- Department of Ophthalmology, Medical University of Graz, Graz, Austria
| | - Milda Reith
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Laura Kuehlewein
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Ronja Jung
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Saskia Holocher
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Krunoslav Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | - Melanie Kempf
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
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2
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Szewczuk A, Wawrzyniak ZM, Szaflik JP, Zaleska-Żmijewska A. Is Primary Open-Angle Glaucoma a Vascular Disease? Assessment of the Relationship between Retinal Arteriolar Morphology and Glaucoma Severity Using Adaptive Optics. J Clin Med 2024; 13:478. [PMID: 38256612 PMCID: PMC10817033 DOI: 10.3390/jcm13020478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/02/2024] [Accepted: 01/13/2024] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Retinal vascular abnormalities may be associated with glaucomatous damage. Adaptive optics (AO) is a new technology that enables the analysis of retinal vasculature at the cellular level in vivo. The purpose of this study was to evaluate retinal arteriolar parameters using the rtx1 adaptive optics fundus camera (AO-FC) in patients with primary open-angle glaucoma (POAG) at different stages and to investigate the relationship between these parameters and changes in spectral-domain optical coherence tomography (SD-OCT) and perimetry. METHODS Parameters of the retinal supratemporal and infratemporal arterioles (wall thickness (WT), lumen diameter (LD), total diameter (TD), wall-to-lumen ratio (WLR), and cross-sectional area of the vascular wall (WCSA)) were analysed with the rtx1 in 111 POAG eyes, which were divided into three groups according to the severity of the disease, and 70 healthy eyes. The associations between RTX1 values and the cup-to-disk ratio, SD-OCT parameters, and visual field parameters were assessed. RESULTS Compared with the control group, the POAG groups showed significantly smaller TD and LD values (p < 0.05) and significantly higher WLR and WT values (p < 0.05) for the supratemporal and infratemporal arterioles. TD was significantly positively correlated with the retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC) (p < 0.05). LD was significantly positively correlated with the RNFL, GCC, and rim area (p < 0.05). The WLR was significantly negatively correlated with the RNFL, GCC, rim area, and MD (p < 0.05), while it was significantly positively correlated with the cup-to-disc ratio and PSD (p < 0.05). CONCLUSIONS The results suggest that vascular dysfunction is present in POAG, even at a very early stage of glaucoma, and increases with the severity of the disease.
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Affiliation(s)
- Alina Szewczuk
- Department of Ophthalmology, Public Ophthalmic Clinical Hospital (SPKSO), 00-576 Warsaw, Poland
| | - Zbigniew M. Wawrzyniak
- Faculty of Electronics and Information Technology, Warsaw University of Technology, 00-665 Warsaw, Poland;
| | - Jacek P. Szaflik
- Department of Ophthalmology, Public Ophthalmic Clinical Hospital (SPKSO), Medical University of Warsaw, 02-091 Warsaw, Poland; (J.P.S.); (A.Z.-Ż.)
| | - Anna Zaleska-Żmijewska
- Department of Ophthalmology, Public Ophthalmic Clinical Hospital (SPKSO), Medical University of Warsaw, 02-091 Warsaw, Poland; (J.P.S.); (A.Z.-Ż.)
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3
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Neriyanuri S, Bedggood P, Symons RCA, Metha A. Mapping the human parafoveal vascular network to understand flow variability in capillaries. PLoS One 2023; 18:e0292962. [PMID: 37831712 PMCID: PMC10575526 DOI: 10.1371/journal.pone.0292962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
Capillary flow is known to be non-homogenous between vessels and variable over time, for reasons that are poorly understood. The local properties of individual vessels have been shown to have limited explanatory power in this regard. This exploratory study investigates the association of network-level properties such as vessel depth, branch order, and distance from the feeding arteriole with capillary flow. Detailed network connectivity analysis was undertaken in 3 healthy young subjects using flood-illuminated adaptive optics retinal imaging, with axial depth of vessels determined via optical coherence tomography angiography. Forty-one out of 70 vessels studied were of terminal capillary type, i.e. fed from an arterial junction and drained by a venous junction. Approximately half of vessel junctions were amenable to fitting with a model of relative branch diameters, with only a few adhering to Murray's Law. A key parameter of the model (the junction exponent) was found to be inversely related to the average velocity (r = -0.59, p = 0.015) and trough velocity (r = -0.67, p = 0.004) in downstream vessels. Aspects of cellular flow, such as the minimum velocity, were also moderately correlated (r = 0.46, p = 0.009) with distance to the upstream feeding arteriole. Overall, this study shows that capillary network topology contributes significantly to the flow variability in retinal capillaries in human eyes. Understanding the heterogeneity in capillary flow is an important first step before pathological flow states can be properly understood. These results show that flow within capillary vessels is not affected by vessel depths but significantly influenced by the upstream feeder distance as well as the downstream vessel junction exponents, but there remains much to be uncovered regarding healthy capillary flow.
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Affiliation(s)
- Srividya Neriyanuri
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - Phillip Bedggood
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - R. C. Andrew Symons
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
- Department of Surgery, The University of Melbourne, Victoria, Australia
- Centre for Eye Research Australia, Victoria, Australia
- Department of Surgery, Alfred Hospital, Monash University, Victoria, Australia
| | - Andrew Metha
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
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4
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Samelska K, Szaflik JP, Guszkowska M, Kurowska AK, Zaleska-Żmijewska A. Characteristics of Rare Inherited Retinal Dystrophies in Adaptive Optics-A Study on 53 Eyes. Diagnostics (Basel) 2023; 13:2472. [PMID: 37568834 PMCID: PMC10417470 DOI: 10.3390/diagnostics13152472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/21/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) are genetic disorders that lead to the bilateral degeneration of the retina, causing irreversible vision loss. These conditions often manifest during the first and second decades of life, and their primary symptoms can be non-specific. Diagnostic processes encompass assessments of best-corrected visual acuity, fundoscopy, optical coherence tomography, fundus autofluorescence, fluorescein angiography, electrophysiological tests, and genetic testing. This study focuses on the application of adaptive optics (AO), a non-invasive retinal examination, for the assessment of patients with IRDs. AO facilitates the high-quality, detailed observation of retinal photoreceptor structures (cones and rods) and enables the quantitative analysis of parameters such as cone density (DM), cone spacing (SM), cone regularity (REG), and Voronoi analysis (N%6). AO examinations were conducted on eyes diagnosed with Stargardt disease (STGD, N=36), cone dystrophy (CD, N=9), and cone-rod dystrophy (CRD, N=8), and on healthy eyes (N=14). There were significant differences in the DM, SM, REG, and N%6 parameters between the healthy and IRD-affected eyes (p<0.001 for DM, SM, and REG; p=0.008 for N%6). The mean DM in the CD, CRD, and STGD groups was 8900.39/mm2, 9296.32/mm2, and 16,209.66/mm2, respectively, with a significant inter-group difference (p=0.006). The mean SM in the CD, CRD, and STGD groups was 12.37 μm, 14.82 μm, and 9.65 μm, respectively, with a significant difference observed between groups (p=0.002). However, no significant difference was found in REG and N%6 among the CD, CRD, and STGD groups. Significant differences were found in SM and DM between CD and STGD (p=0.014 for SM; p=0.003 for DM) and between CRD and STGD (p=0.027 for SM; p=0.003 for DM). Our findings suggest that AO holds significant potential as an impactful diagnostic tool for IRDs.
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Affiliation(s)
- Katarzyna Samelska
- Department of Ophthalmology, Medical University of Warsaw, 02-091 Warsaw, Poland
- SPKSO Ophthalmic University Hospital, 00-576 Warsaw, Poland
| | - Jacek Paweł Szaflik
- Department of Ophthalmology, Medical University of Warsaw, 02-091 Warsaw, Poland
- SPKSO Ophthalmic University Hospital, 00-576 Warsaw, Poland
| | | | - Anna Katarzyna Kurowska
- Department of Ophthalmology, Medical University of Warsaw, 02-091 Warsaw, Poland
- SPKSO Ophthalmic University Hospital, 00-576 Warsaw, Poland
| | - Anna Zaleska-Żmijewska
- Department of Ophthalmology, Medical University of Warsaw, 02-091 Warsaw, Poland
- SPKSO Ophthalmic University Hospital, 00-576 Warsaw, Poland
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5
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Rizzoni D, Agabiti-Rosei C, Boari GEM, Muiesan ML, De Ciuceis C. Microcirculation in Hypertension: A Therapeutic Target to Prevent Cardiovascular Disease? J Clin Med 2023; 12:4892. [PMID: 37568294 PMCID: PMC10419740 DOI: 10.3390/jcm12154892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/18/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023] Open
Abstract
Arterial hypertension is a common condition worldwide and an important risk factor for cardio- and cerebrovascular events, renal diseases, as well as microvascular eye diseases. Established hypertension leads to the chronic vasoconstriction of small arteries as well as to a decreased lumen diameter and the thickening of the arterial media or wall with a consequent increased media-to-lumen ratio (MLR) or wall-to-lumen ratio (WLR). This process, defined as vascular remodeling, was firstly demonstrated in small resistance arteries isolated from subcutaneous biopsies and measured by micromyography, and this is still considered the gold-standard method for the assessment of structural alterations in small resistance arteries; however, microvascular remodeling seems to represent a generalized phenomenon. An increased MLR may impair the organ flow reserve, playing a crucial role in the maintenance and, probably, also in the progressive worsening of hypertensive disease, as well as in the development of hypertension-mediated organ damage and related cardiovascular events, thus possessing a relevant prognostic relevance. New non-invasive techniques, such as scanning laser Doppler flowmetry or adaptive optics, are presently under development, focusing mainly on the evaluation of WLR in retinal arterioles; recently, also retinal microvascular WLR was demonstrated to have a prognostic impact in terms of cardio- and cerebrovascular events. A rarefaction of the capillary network has also been reported in hypertension, which may contribute to flow reduction in and impairment of oxygen delivery to different tissues. These microvascular alterations seem to represent an early step in hypertension-mediated organ damage since they might contribute to microvascular angina, stroke, and renal dysfunction. In addition, they can be markers useful in monitoring the beneficial effects of antihypertensive treatment. Additionally, conductance arteries may be affected by a remodeling process in hypertension, and an interrelationship is present in the structural changes in small and large conductance arteries. The review addresses the possible relations between structural microvascular alterations and hypertension-mediated organ damage, and their potential improvement with antihypertensive treatment.
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Affiliation(s)
- Damiano Rizzoni
- Department of Clinical and Experimental Sciences, University of Brescia, 25121 Brescia, Italy; (C.A.-R.); (M.L.M.); (C.D.C.)
| | - Claudia Agabiti-Rosei
- Department of Clinical and Experimental Sciences, University of Brescia, 25121 Brescia, Italy; (C.A.-R.); (M.L.M.); (C.D.C.)
- Second Division of Medicine, Spedali Civili di Brescia, 25123 Brescia, Italy
| | - Gianluca E. M. Boari
- Division of Medicine, Spedali Civili di Brescia, Montichiari, 25123 Brescia, Italy;
| | - Maria Lorenza Muiesan
- Department of Clinical and Experimental Sciences, University of Brescia, 25121 Brescia, Italy; (C.A.-R.); (M.L.M.); (C.D.C.)
- Second Division of Medicine, Spedali Civili di Brescia, 25123 Brescia, Italy
| | - Carolina De Ciuceis
- Department of Clinical and Experimental Sciences, University of Brescia, 25121 Brescia, Italy; (C.A.-R.); (M.L.M.); (C.D.C.)
- Second Division of Medicine, Spedali Civili di Brescia, 25123 Brescia, Italy
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6
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Ashourizadeh H, Fakhri M, Hassanpour K, Masoudi A, Jalali S, Roshandel D, Chen FK. Pearls and Pitfalls of Adaptive Optics Ophthalmoscopy in Inherited Retinal Diseases. Diagnostics (Basel) 2023; 13:2413. [PMID: 37510157 PMCID: PMC10377978 DOI: 10.3390/diagnostics13142413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/12/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Adaptive optics (AO) retinal imaging enables individual photoreceptors to be visualized in the clinical setting. AO imaging can be a powerful clinical tool for detecting photoreceptor degeneration at a cellular level that might be overlooked through conventional structural assessments, such as spectral-domain optical coherence tomography (SD-OCT). Therefore, AO imaging has gained significant interest in the study of photoreceptor degeneration, one of the most common causes of inherited blindness. Growing evidence supports that AO imaging may be useful for diagnosing early-stage retinal dystrophy before it becomes apparent on fundus examination or conventional retinal imaging. In addition, serial AO imaging may detect structural disease progression in early-stage disease over a shorter period compared to SD-OCT. Although AO imaging is gaining popularity as a structural endpoint in clinical trials, the results should be interpreted with caution due to several pitfalls, including the lack of standardized imaging and image analysis protocols, frequent ocular comorbidities that affect image quality, and significant interindividual variation of normal values. Herein, we summarize the current state-of-the-art AO imaging and review its potential applications, limitations, and pitfalls in patients with inherited retinal diseases.
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Affiliation(s)
| | - Maryam Fakhri
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Sciences, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
| | - Kiana Hassanpour
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Sciences, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
| | - Ali Masoudi
- Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Sattar Jalali
- Department of Physics, Central Tehran Branch, Islamic Azad University, Tehran 19558, Iran
| | - Danial Roshandel
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, WA 6009, Australia
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, WA 6009, Australia
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, WA 6009, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC 3010, Australia
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7
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Valterova E, Unterlauft JD, Francke M, Kirsten T, Kolar R, Rauscher FG. Comprehensive automatic processing and analysis of adaptive optics flood illumination retinal images on healthy subjects. BIOMEDICAL OPTICS EXPRESS 2023; 14:945-970. [PMID: 36874506 PMCID: PMC9979672 DOI: 10.1364/boe.471881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 05/02/2023]
Abstract
This work presents a novel fully automated method for retinal analysis in images acquired with a flood illuminated adaptive optics retinal camera (AO-FIO). The proposed processing pipeline consists of several steps: First, we register single AO-FIO images in a montage image capturing a larger retinal area. The registration is performed by combination of phase correlation and the scale-invariant feature transform method. A set of 200 AO-FIO images from 10 healthy subjects (10 images from left eye and 10 images from right eye) is processed into 20 montage images and mutually aligned according to the automatically detected fovea center. As a second step, the photoreceptors in the montage images are detected using a method based on regional maxima localization, where the detector parameters were determined with Bayesian optimization according to manually labeled photoreceptors by three evaluators. The detection assessment, based on Dice coefficient, ranges from 0.72 to 0.8. In the next step, the corresponding density maps are generated for each of the montage images. As a final step, representative averaged photoreceptor density maps are created for the left and right eye and thus enabling comprehensive analysis across the montage images and a straightforward comparison with available histological data and other published studies. Our proposed method and software thus enable us to generate AO-based photoreceptor density maps for all measured locations fully automatically, and thus it is suitable for large studies, as those are in pressing need for automated approaches. In addition, the application MATADOR (MATlab ADaptive Optics Retinal Image Analysis) that implements the described pipeline and the dataset with photoreceptor labels are made publicly available.
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Affiliation(s)
- Eva Valterova
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czech Republic
- Department of Medical Data Science, Leipzig University Medical Center, Leipzig, Germany
| | - Jan D. Unterlauft
- Department of Ophthalmology, Leipzig University Medical Center, Leipzig, Germany
- Universitäts-Augenklinik Bern, Inselspital, Freiburgstr., 3010, Bern, Switzerland
| | - Mike Francke
- Institute for Medical Informatics, Statistics, and Epidemiology, Leipzig University, Leipzig, Germany
| | - Toralf Kirsten
- Department of Medical Data Science, Leipzig University Medical Center, Leipzig, Germany
- Institute for Medical Informatics, Statistics, and Epidemiology, Leipzig University, Leipzig, Germany
- Database Group, Faculty of Bio Sciences and Computer Sciences, Mittweida University of Applied Sciences, Mittweida, Germany
| | - Radim Kolar
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czech Republic
- Equally contributing
| | - Franziska G. Rauscher
- Institute for Medical Informatics, Statistics, and Epidemiology, Leipzig University, Leipzig, Germany
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Equally contributing
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8
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Morgan JIW, Chui TYP, Grieve K. Twenty-five years of clinical applications using adaptive optics ophthalmoscopy [Invited]. BIOMEDICAL OPTICS EXPRESS 2023; 14:387-428. [PMID: 36698659 PMCID: PMC9841996 DOI: 10.1364/boe.472274] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/22/2022] [Accepted: 11/27/2022] [Indexed: 05/02/2023]
Abstract
Twenty-five years ago, adaptive optics (AO) was combined with fundus photography, thereby initiating a new era in the field of ophthalmic imaging. Since that time, clinical applications of AO ophthalmoscopy to investigate visual system structure and function in both health and disease abound. To date, AO ophthalmoscopy has enabled visualization of most cell types in the retina, offered insight into retinal and systemic disease pathogenesis, and been integrated into clinical trials. This article reviews clinical applications of AO ophthalmoscopy and addresses remaining challenges for AO ophthalmoscopy to become fully integrated into standard ophthalmic care.
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Affiliation(s)
- Jessica I. W. Morgan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Contributed equally
| | - Toco Y. P. Chui
- Department of Ophthalmology, The New York Eye and Ear Infirmary of Mount Sinai, New York, NY 10003, USA
- Contributed equally
| | - Kate Grieve
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, and CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, F-75012 Paris, France
- Contributed equally
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Evaluation of Morphological Changes in Retinal Vessels in Type 1 Diabetes Mellitus Patients with the Use of Adaptive Optics. Biomedicines 2022; 10:biomedicines10081926. [PMID: 36009472 PMCID: PMC9406131 DOI: 10.3390/biomedicines10081926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 12/05/2022] Open
Abstract
Introduction. Diabetes mellitus contributes to the development of microvascular complications in the eye. Moreover, it affects multiple end organs, including brain damage, leading to premature death. The use of adaptive optics technique allows to perform non-invasive in vivo assessment of retinal vessels and to identify changes in arterioles about 100 μm in diameter. The retinal vasculature may be a model of the cerebral vessels both morphologically and functionally. Aim. To evaluate morphological parameters of retinal arterioles in patients with type 1 diabetes mellitus (DM1). Material and methods. The study included 22 DM1 patients (13 females) aged 43.00 ± 9.45 years with a mean diabetes duration of 22.55 ± 10.05 years, and 23 healthy volunteers (10 females) aged 41.09 ± 10.99 years. Blood pressure, BMI, waist circumference, and metabolic control markers of diabetes were measured in both groups. Vascular examinations were performed using an rtx1 adaptive optics retinal camera (Imagine Eyes, Orsay, France); the vessel wall thickness (WT), lumen diameter (LD), wall-to-lumen ratio (WLR), and vascular wall cross-sectional area (WCSA) were assessed. Statistical analysis was performed with the application of IMB SPSS version 23 software. Results. The DM1 group did not differ significantly in age, BMI, waist circumference, blood pressure, or axial length of the eye compared to the control group. Intraocular pressure (IOP) in both groups was normal, but in the DM1 group it was significantly higher. The DM1 group had significantly higher WT, WLR, and WCSA. These parameters correlated significantly with the duration of diabetes, but not with IOP. Conclusions. The presented study demonstrates the presence of significant morphological changes in retinal vessels in DM1 patients without previously diagnosed diabetic retinopathy. Similar changes may occur in the brain and may be early indicators of cardiovascular risk, but further investigation is required to confirm that.
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Tan W, Yao X, Le TT, Tan B, Schmetterer L, Chua J. The New Era of Retinal Imaging in Hypertensive Patients. Asia Pac J Ophthalmol (Phila) 2022; 11:149-159. [PMID: 35533334 DOI: 10.1097/apo.0000000000000509] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
ABSTRACT Structural and functional alterations in the microcirculation by systemic hypertension can cause significant organ damage at the eye, heart, brain, and kidneys. As the retina is the only tissue in the body that allows direct imaging of small vessels, the relationship of hypertensive retinopathy signs with development of disease states in other organs have been extensively studied; large-scale epidemiological studies using fundus photography and advanced semi-automated analysis software have reported the association of retinopathy signs with hypertensive end-organ damage includes the following: stroke, dementia, and coronary heart disease. Although yielding much useful information, the vessels assessed from fundus photographs remain limited to the larger retinal arterioles and venules, and abnormalities observed may not be that of the earliest changes. Newer imaging modalities such as optical coherence tomography angiography and adaptive optics technology, which allow a greater precision in the structural quantification of retinal vessels, including capillaries, may facilitate the assessment and management of these patients. The advent of deep learning technology has also augmented the utility of fundus photographs to help create diagnostic and risk stratification systems. Particularly, deep learning systems have been shown in several large studies to be able to predict multiple cardiovascular risk factors, major adverse cardiovascular events within 5 years, and presence of coronary artery calcium, from fundus photographs alone. In the future, combining deep learning systems with the imaging precision offered by optical coherence tomography angiography and adaptive optics could pave way for systems that are able to predict adverse clinical outcomes even more accurately.
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Affiliation(s)
- Wilson Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Xinwen Yao
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
| | - Thu-Thao Le
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-National University of Singapore Medical School, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-National University of Singapore Medical School, Singapore
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-National University of Singapore Medical School, Singapore
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Rizzoni D, Mengozzi A, Masi S, Agabiti Rosei C, De Ciuceis C, Virdis A. New Noninvasive Methods to Evaluate Microvascular Structure and Function. Hypertension 2022; 79:874-886. [PMID: 35114816 DOI: 10.1161/hypertensionaha.121.17954] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The structural and functional alterations of microvessels are detected because of physiological aging and in several cardiometabolic diseases, including hypertension, diabetes, and obesity. The small resistance arteries of these patients show an increase in the media or total wall thickness to internal lumen diameter ratio (MLR or WLR), often accompanied by endothelial dysfunction. For decades, micromyography has been considered as a gold standard method for evaluating microvascular structural alterations through the measurement of MLR or WLR of subcutaneous small vessels dissected from tissue biopsies. Micromyography is the most common and reliable method for assessing microcirculatory endothelial function ex vivo, while strain-gauge venous plethysmography is considered the reference technique for in vivo studies. Recently, several noninvasive methods have been proposed to extend the microvasculature evaluation to a broader range of patients and clinical settings. Scanning laser Doppler flowmetry and adaptive optics are increasingly used to estimate the WLR of retinal arterioles. Microvascular endothelial function may be evaluated in the retina by flicker light stimulus, in the finger by tonometric approaches, or in the cutaneous or sublingual tissues by laser Doppler flowmetry or intravital microscopy. The main limitation of these techniques is the lack of robust evidence on their prognostic value, which currently reduces their widespread use in daily clinical practice. Ongoing and future studies will overcome this issue, hopefully moving the noninvasive assessment of the microvascular function and structure from bench to bedside.
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Affiliation(s)
- Damiano Rizzoni
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Italy (D.R., C.A., C.D.C.).,Division of Medicine, Spedali Civili di Brescia, Montichiari (Brescia), Italy (D.R.)
| | - Alessandro Mengozzi
- Department of Clinical and Experimental Medicine, University of Pisa, Italy (A.M., S.M., A.V.).,Institute of Life Science, Sant'Anna School of Advanced Studies, Pisa, Italy (A.M.)
| | - Stefano Masi
- Department of Clinical and Experimental Medicine, University of Pisa, Italy (A.M., S.M., A.V.).,Institute of Cardiovascular Science, University College London, United Kingdom (S.M.)
| | - Claudia Agabiti Rosei
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Italy (D.R., C.A., C.D.C.)
| | - Carolina De Ciuceis
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Italy (D.R., C.A., C.D.C.)
| | - Agostino Virdis
- Department of Clinical and Experimental Medicine, University of Pisa, Italy (A.M., S.M., A.V.)
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12
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Feng Z, Wang G, Xia H, Li M, Liang G, Dong T, Xiao P, Yuan J. Macular Vascular Geometry Changes With Sex and Age in Healthy Subjects: A Fundus Photography Study. Front Med (Lausanne) 2021; 8:778346. [PMID: 34977079 PMCID: PMC8714757 DOI: 10.3389/fmed.2021.778346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/17/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: To characterize the sex- and age-related alterations of the macular vascular geometry in a population of healthy eyes using fundus photography. Methods: A cross-sectional study was conducted with 610 eyes from 305 healthy subjects (136 men, 169 women) who underwent fundus photography examination and was divided into four age groups (G1 with age ≤ 25 years, G2 with age 26–35 years, G3 with age 36–45 years, and G4 with age ≥ 46 years). A self-developed automated retinal vasculature analysis system allowed segmentation and separate multiparametric quantification of the macular vascular network according to the Early Treatment Diabetic Retinopathy Study (ETDRS). Vessel fractal dimension (Df), vessel area rate (VAR), average vessel diameter (Dm), and vessel tortuosity (τn) were acquired and compared between sex and age groups. Results: There was no significant difference between the mean age of male and female subjects (32.706 ± 10.372 and 33.494 ± 10.620, respectively, p > 0.05) and the mean age of both sexes in each age group (p > 0.05). The Df, VAR, and Dm of the inner ring, the Df of the outer ring, and the Df and VAR of the whole macula were significantly greater in men than women (p < 0.001, p < 0.001, p < 0.05, respectively). There was no significant change of τn between males and females (p > 0.05). The Df, VAR, and Dm of the whole macula, the inner and outer rings associated negatively with age (p < 0.001), whereas the τn showed no significant association with age (p > 0.05). Comparison between age groups observed that Df started to decrease from G2 compared with G1 in the inner ring (p < 0.05) and Df, VAR, and Dm all decreased from G3 compared with the younger groups in the whole macula, inner and outer rings (p < 0.05). Conclusion: In the healthy subjects, macular vascular geometric parameters obtained from fundus photography showed that Df, VAR, and Dm are related to sex and age while τn is not. The baseline values of the macular vascular geometry were also acquired for both sexes and all age groups.
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Affiliation(s)
- Ziqing Feng
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Gengyuan Wang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Honghui Xia
- Department of Ophthalmology, Zhaoqing Gaoyao People's Hospital, Zhaoqing, China
| | - Meng Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Guoxia Liang
- Department of Ophthalmology, Zhaoqing Gaoyao People's Hospital, Zhaoqing, China
| | - Tingting Dong
- Department of Ophthalmology, Zhaoqing Gaoyao People's Hospital, Zhaoqing, China
| | - Peng Xiao
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Peng Xiao
| | - Jin Yuan
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangdong Provincial Clinical Research Center for Ocular Diseases, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- Jin Yuan
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13
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Wynne N, Carroll J, Duncan JL. Promises and pitfalls of evaluating photoreceptor-based retinal disease with adaptive optics scanning light ophthalmoscopy (AOSLO). Prog Retin Eye Res 2021; 83:100920. [PMID: 33161127 PMCID: PMC8639282 DOI: 10.1016/j.preteyeres.2020.100920] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/28/2020] [Accepted: 10/31/2020] [Indexed: 12/15/2022]
Abstract
Adaptive optics scanning light ophthalmoscopy (AOSLO) allows visualization of the living human retina with exquisite single-cell resolution. This technology has improved our understanding of normal retinal structure and revealed pathophysiological details of a number of retinal diseases. Despite the remarkable capabilities of AOSLO, it has not seen the widespread commercial adoption and mainstream clinical success of other modalities developed in a similar time frame. Nevertheless, continued advancements in AOSLO hardware and software have expanded use to a broader range of patients. Current devices enable imaging of a number of different retinal cell types, with recent improvements in stimulus and detection schemes enabling monitoring of retinal function, microscopic structural changes, and even subcellular activity. This has positioned AOSLO for use in clinical trials, primarily as exploratory outcome measures or biomarkers that can be used to monitor disease progression or therapeutic response. AOSLO metrics could facilitate patient selection for such trials, to refine inclusion criteria or to guide the choice of therapy, depending on the presence, absence, or functional viability of specific cell types. Here we explore the potential of AOSLO retinal imaging by reviewing clinical applications as well as some of the pitfalls and barriers to more widespread clinical adoption.
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Affiliation(s)
- Niamh Wynne
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Carroll
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, CA, USA.
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14
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Bakker E, Dikland FA, van Bakel R, Andrade De Jesus D, Sánchez Brea L, Klein S, van Walsum T, Rossant F, Farías DC, Grieve K, Paques M. Adaptive optics ophthalmoscopy: a systematic review of vascular biomarkers. Surv Ophthalmol 2021; 67:369-387. [PMID: 34090882 DOI: 10.1016/j.survophthal.2021.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/17/2021] [Accepted: 05/24/2021] [Indexed: 12/28/2022]
Abstract
Retinal vascular diseases are a leading cause for blindness and partial sight certifications. By applying adaptive optics (AO) to conventional imaging modalities, the microstructures of the retinal vasculature can be observed with high spatial resolution, hence offering a unique opportunity for the exploration of the human microcirculation. The objective of this systematic review is to describe the current state of retinal vascular biomarkers imaged by AO flood illumination ophthalmoscopy (FIO) and AO scanning laser ophthalmoscopy (SLO). A literature research was conducted in the PubMed and Scopus databases on July 9, 2020. From 217 screened studies, 42 were eligible for this review. All studies underwent a quality check regarding their content. A meta-analysis was performed for the biomarkers reported for the same pathology in at least three studies using the same modality. The most frequently studied vascular biomarkers were the inner diameter (ID), outer diameter (OD), parietal thickness (PT), wall cross-sectional area (WCSA), and wall-to-lumen ratio (WLR). The applicability of AO vascular biomarkers has been mostly explored in systemic hypertension using AO FIO and in diabetes using AO SLO. The result of the meta-analysis for hypertensive patients showed that WLR, PT, and ID were significantly different when compared to healthy controls, while WCSA was not (P < 0.001, P = 0.002, P < 0.001, and P = 0.070, respectively). The presented review shows that, although a substantial number of retinal vascular biomarkers have been explored in AO en face imaging, further clinical research and standardization of procedures is needed to validate such biomarkers for the longitudinal monitoring of arterial hypertension and other diseases.
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Affiliation(s)
- Elise Bakker
- Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands; Clinical Technology, Delft University of Technology, Delft, The Netherlands
| | - Felix Anne Dikland
- Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands; Clinical Technology, Delft University of Technology, Delft, The Netherlands
| | - Roan van Bakel
- Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands; Clinical Technology, Delft University of Technology, Delft, The Netherlands
| | - Danilo Andrade De Jesus
- Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands.
| | - Luisa Sánchez Brea
- Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Stefan Klein
- Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Theo van Walsum
- Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Florence Rossant
- ISEP, Institut Supérieur d'Electronique de Paris, Issy-les-Moulineaux, France
| | - Daniela Castro Farías
- Paris Eye Imaging Group, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS Clinical Investigation Center, Paris, France
| | - Kate Grieve
- Paris Eye Imaging Group, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS Clinical Investigation Center, Paris, France
| | - Michel Paques
- Paris Eye Imaging Group, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS Clinical Investigation Center, Paris, France
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15
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Abstract
BACKGROUND Cerebrovascular disease (CeVD), including stroke, is a leading cause of death globally. The retina is an extension of the cerebrum, sharing embryological and vascular pathways. The association between different retinal signs and CeVD has been extensively evaluated. In this review, we summarize recent studies which have examined this association. EVIDENCE ACQUISITION We searched 6 databases through July 2019 for studies evaluating the link between retinal vascular signs and diseases with CeVD. CeVD was classified into 2 groups: clinical CeVD (including clinical stroke, silent cerebral infarction, cerebral hemorrhage, and stroke mortality), and sub-clinical CeVD (including MRI-defined lacunar infarct and white matter lesions [WMLs]). Retinal vascular signs were classified into 3 groups: classic hypertensive retinopathy (including retinal microaneurysms, retinal microhemorrhage, focal/generalized arteriolar narrowing, cotton-wool spots, and arteriovenous nicking), clinical retinal diseases (including diabetic retinopathy [DR], age-related macular degeneration [AMD], retinal vein occlusion, retinal artery occlusion [RAO], and retinal emboli), and retinal vascular imaging measures (including retinal vessel diameter and geometry). We also examined emerging retinal vascular imaging measures and the use of artificial intelligence (AI) deep learning (DL) techniques. RESULTS Hypertensive retinopathy signs were consistently associated with clinical CeVD and subclinical CeVD subtypes including subclinical cerebral large artery infarction, lacunar infarction, and WMLs. Some clinical retinal diseases such as DR, retinal arterial and venous occlusion, and transient monocular vision loss are consistently associated with clinical CeVD. There is an increased risk of recurrent stroke immediately after RAO. Less consistent associations are seen with AMD. Retinal vascular imaging using computer assisted, semi-automated software to measure retinal vascular caliber and other parameters (tortuosity, fractal dimension, and branching angle) has shown strong associations to clinical and subclinical CeVD. Other new retinal vascular imaging techniques (dynamic retinal vessel analysis, adaptive optics, and optical coherence tomography angiography) are emerging technologies in this field. Application of AI-DL is expected to detect subclinical retinal changes and discrete retinal features in predicting systemic conditions including CeVD. CONCLUSIONS There is extensive and increasing evidence that a range of retinal vascular signs and disease are closely linked to CeVD, including subclinical and clinical CeVD. New technology including AI-DL will allow further translation to clinical utilization.
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16
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Bedggood P, Metha A. Adaptive optics imaging of the retinal microvasculature. Clin Exp Optom 2021; 103:112-122. [DOI: 10.1111/cxo.12988] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 12/31/2022] Open
Affiliation(s)
- Phillip Bedggood
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia,
| | - Andrew Metha
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia,
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17
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The Relation between Body Mass Index and Retinal Photoreceptor Morphology and Microvascular Changes Measured with Adaptive Optics (rtx1) High-Resolution Imaging. J Ophthalmol 2021; 2021:6642059. [PMID: 33728057 PMCID: PMC7935605 DOI: 10.1155/2021/6642059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 02/11/2021] [Accepted: 02/17/2021] [Indexed: 11/20/2022] Open
Abstract
Background Overweight and obese patients are at risk for diabetes, cardiovascular disorders, and microvascular complications. The rtx1TM (Imagine Eyes, France) is a microscope that allows near histological visualizations of cones and retinal microcirculation. Objective This study analysed the cones and retinal microvascular changes in a group of 47 healthy women with different BMI values. Participants were divided into 2 groups: the BMI group (28 women with BMI >/25) and the control group (19 lean women with BMI <25). Results The lumen and diameter of retinal arteries were not significantly different between groups. There were significant differences in the thickness of arteriole walls. The WLR and WCSA values differed significantly between the control and BMI groups (for WLR 0.25 ± 0.03 vs. 0.29 ± 0.03, p < 0.001; for WCSA 4136.7 ± 1140.0 vs. 5217.3 ± 944.0, respectively, p < 0.001). In healthy eyes, cone density and morphology were not affected by weight. Conclusions Retinal image analysis with rtx1 offers a novel noninvasive measurement of early changes in retinal vasculature that are not detectable during routine clinical examination. Abnormalities of retinal arterioles found by rtx1™examination should be considered as a strong risk factor for cardiovascular changes resulting from overweight and obesity.
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18
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Association of changes of retinal vessels diameter with ocular blood flow in eyes with diabetic retinopathy. Sci Rep 2021; 11:4653. [PMID: 33633255 PMCID: PMC7907275 DOI: 10.1038/s41598-021-84067-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/09/2021] [Indexed: 12/25/2022] Open
Abstract
We investigated morphological changes of retinal arteries to determine their association with the blood flow and systemic variables in type 2 diabetes patients. The patients included 47 non-diabetic retinopathy eyes, 36 mild or moderate nonproliferative diabetic retinopathy (M-NPDR) eyes, 22 severe NPDR (S-NPDR) eyes, 32 PDR eyes, and 24 normal eyes as controls. The mean wall to lumen ratio (WLR) measured by adaptive optics camera was significantly higher in the PDR groups than in all of the other groups (all P < 0.001). However, the external diameter of the retinal vessels was not significantly different among the groups. The mean blur rate (MBR)-vessel determined by laser speckle flowgraphy was significantly lower in the PDR group than in the other groups (P < 0.001). The WLR was correlated with MBR-vessel (r = − 0.337, P < 0.001), duration of disease (r = 0.191, P = 0.042), stage of DM (r = 0.643, P < 0.001), systolic blood pressure (r = 0.166, P < 0.037), and presence of systemic hypertension (r = 0.443, P < 0.001). Multiple regression analysis demonstrated that MBR-vessel (β = − 0.389, P < 0.001), presence of systemic hypertension (β = 0.334, P = 0.001), and LDL (β = 0.199, P = 0.045) were independent factors significantly associated with the WLR. The increased retinal vessel wall thickness led to a narrowing of lumen diameter and a decrease in the blood flow in the PDR group.
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19
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Akyol E, Hagag AM, Sivaprasad S, Lotery AJ. Adaptive optics: principles and applications in ophthalmology. Eye (Lond) 2021; 35:244-264. [PMID: 33257798 PMCID: PMC7852593 DOI: 10.1038/s41433-020-01286-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 10/19/2020] [Accepted: 11/04/2020] [Indexed: 12/26/2022] Open
Abstract
This is a comprehensive review of the principles and applications of adaptive optics (AO) in ophthalmology. It has been combined with flood illumination ophthalmoscopy, scanning laser ophthalmoscopy, as well as optical coherence tomography to image photoreceptors, retinal pigment epithelium (RPE), retinal ganglion cells, lamina cribrosa and the retinal vasculature. In this review, we highlight the clinical studies that have utilised AO to understand disease mechanisms. However, there are some limitations to using AO in a clinical setting including the cost of running an AO imaging service, the time needed to scan patients, the lack of normative databases and the very small size of area imaged. However, it is undoubtedly an exceptional research tool that enables visualisation of the retina at a cellular level.
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Affiliation(s)
- Engin Akyol
- Faculty of Medicine, University of Southampton, Southampton, SO17 1BJ, UK
| | - Ahmed M Hagag
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
| | - Sobha Sivaprasad
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
| | - Andrew J Lotery
- Faculty of Medicine, University of Southampton, Southampton, SO17 1BJ, UK.
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20
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Cífková R, Harazny JM, Bruthans J, Wohlfahrt P, Krajčoviechová A, Lánská V, Gelžinský J, Mateřánková M, Mareš Š, Filipovský J, Mayer O, Schmieder RE. Reference values of retinal microcirculation parameters derived from a population random sample. Microvasc Res 2020; 134:104117. [PMID: 33245956 DOI: 10.1016/j.mvr.2020.104117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/21/2020] [Accepted: 11/21/2020] [Indexed: 11/17/2022]
Abstract
Retinal microcirculation reflects retinal perfusion abnormalities and retinal arterial structural changes at relatively early stages of various cardiovascular diseases. Our objective has been to establish reference values for major functional and structural parameters of retinal microcirculation in a randomly selected urban population sample. A total of 398 randomly selected individuals from an urban population aged 25 to 65 years, resident in Pilsen, Czech Republic, were screened for major cardiovascular risk factors. Retinal microcirculation was assessed using scanning laser Doppler flowmetry (SLDF), with data evaluable in 343 patients. Of this number, complete data were available for 256 individuals free from manifest cardiovascular disease, diabetes and drug treatment for hypertension and/or dyslipidemia, constituting the reference value population. Juxtapapillary retinal capillary blood flow has increased significantly with age whereas vessel and luminal diameters have decreased. No sex differences in retinal microcirculation parameters have been found. Therefore, reference values for retinal microcirculation parameters have been established by age groups. Unattended automated office systolic BP, after adjusting for age, correlated significantly with wall-to-lumen ratio (WLR) and wall thickness (WT). Moreover, after adjusting for age and mean BP, a positive relationship has been found between carotid femoral pulse wave velocity and WT, WLR and wall cross-sectional area, indicating the interaction between micro- and macro-vasculature. In conclusion, our study is the first to provide reference values of retinal microcirculation parameters in a random Caucasian population sample. Our results have shown that, at the population level, the first structural changes in retinal microcirculation are those in lumen diameters. Of note, a close relationship between BP and vascular remodeling of retinal arterioles and between aortic stiffness and WLR of retinal arterioles suggests an interaction between micro- and macro-vasculature.
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Affiliation(s)
- Renata Cífková
- Center for Cardiovascular Prevention, Charles University in Prague, First Faculty of Medicine and Thomayer Hospital, Prague, Czech Republic; Department of Medicine II, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
| | - Joanna M Harazny
- Department of Nephrology and Hypertension, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany; Department of Human Physiology and Pathophysiology, University of Warmia and Mazury, Olsztyn, Poland
| | - Jan Bruthans
- Center for Cardiovascular Prevention, Charles University in Prague, First Faculty of Medicine and Thomayer Hospital, Prague, Czech Republic; 2nd Department of Internal Medicine, Faculty of Medicine, Charles University, Pilsen, Czech Republic
| | - Peter Wohlfahrt
- Center for Cardiovascular Prevention, Charles University in Prague, First Faculty of Medicine and Thomayer Hospital, Prague, Czech Republic
| | - Alena Krajčoviechová
- Center for Cardiovascular Prevention, Charles University in Prague, First Faculty of Medicine and Thomayer Hospital, Prague, Czech Republic
| | - Věra Lánská
- Medical Statistics Unit, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Július Gelžinský
- 2nd Department of Internal Medicine, Faculty of Medicine, Charles University, Pilsen, Czech Republic
| | - Markéta Mateřánková
- 2nd Department of Internal Medicine, Faculty of Medicine, Charles University, Pilsen, Czech Republic
| | - Štěpán Mareš
- 2nd Department of Internal Medicine, Faculty of Medicine, Charles University, Pilsen, Czech Republic
| | - Jan Filipovský
- 2nd Department of Internal Medicine, Faculty of Medicine, Charles University, Pilsen, Czech Republic
| | - Otto Mayer
- 2nd Department of Internal Medicine, Faculty of Medicine, Charles University, Pilsen, Czech Republic
| | - Roland E Schmieder
- Department of Nephrology and Hypertension, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany
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21
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Morphologic Analysis of Peripapillary Retinal Arteriole Using Adaptive Optics in Primary Open-angle Glaucoma. J Glaucoma 2020; 29:271-275. [PMID: 31977547 DOI: 10.1097/ijg.0000000000001452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE The purpose of this study was to better understand the role of vascular risk factors in the pathogenesis of primary open-angle glaucoma (POAG), a detailed analysis of retinal arterial wall thickness is needed. The purpose of the present study was to make a morphologic analysis of peripapillary arteriole in POAG using adaptive optics (AO) technology. PATIENTS AND METHODS We included otherwise healthy subjects with an isolated confirmed diagnosis of bilateral POAG. Patients' clinical characteristics were noted. AO imaging followed by a complete ophthalmic examination was performed. A single operator masked to clinical data performed 5 measurements at different locations of each analyzed vessel. For each location, lumen diameter and wall thickness were measured. Total diameter, wall-to-lumen ratio (WLR), and whole cross-sectional area were calculated. RESULTS Lumen diameter and total diameter were significantly lower in the glaucoma group (n=31) than in the control group (n=29): [median (interquartile ranges)] 88.3 (82.6-99.2) versus 102.3 (87-113.1) (P=0.03) and 121.1 (109.3-130.5) versus 134.4 (112.7-144.4), respectively (P=0.015). Wall thickness, WLR, and whole cross-sectional area were not significantly different. Apart from a significantly higher WLR in subjects with reported high cholesterol levels, we did not observe any correlation between patients' clinical characteristics and any of the parameters. CONCLUSIONS We observed in POAG a narrowing of the arteriolar lumen without modification of the vessel wall thickness. To date, it is the first time that these data are obtained using AO. This suggests that the vascular risk factor in POAG only reduces the vascular caliber without inducing any patent atherosclerosis of the retinal arterial wall.
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22
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Mehta RA, Akkali MC, Jayadev C, Anuj A, Yadav NK. Morphometric analysis of retinal arterioles in control and hypertensive population using adaptive optics imaging. Indian J Ophthalmol 2020; 67:1673-1677. [PMID: 31546506 PMCID: PMC6786142 DOI: 10.4103/ijo.ijo_253_19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Purpose: To measure the wall-to-lumen ratio (WLR) and the vascular wall cross-sectional area (WCSA) of retinal arterioles by an Adaptive Optics (AO) retinal camera using semi-automated software and comparing them between control and hypertensive population. Methods: This was a cross-sectional observational study including a hypertensive group and a control group. Subjects were examined and their medical history recorded. Retinal arteriolar morphometry was assessed by rtx1 AO retinal camera using AOdetect Artery semiautomated software. Main Outcome Measures: WLR and WCSA were measured on the basis of retinal arteriolar wall thickness (W1, W2), lumen diameter (LD) and vessel diameter (VD). Influence of age and arterial hypertension on the WLR and WCSA were examined. Results: A total of 150 human subjects were included out of which 110 were controls and 40 were hypertensives under treatment. There was statistically significant difference in the age, systolic and diastolic blood pressures between the control and hypertensive groups (P < 0.01). We found no significant correlation between age and WLR (R2 = 0.049, P > 0.05) or age and WCSA (R2 = 0.045, P > 0.05). We observed a significant difference in WLR and WCSA measurements between control and hypertensive groups (P < 0.01). On measuring intra-observer variability (IOV) we found excellent consistency. Conclusion: AO retinal imaging allows a direct measurement of the retinal vessel wall and LD with excellent IOV. WLR and WCSA reflect the remodelling process and can be used to further aid the early detection and monitoring of systemic hypertension.
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Affiliation(s)
- Ruchir A Mehta
- Department of Vitreoretina, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Mukund C Akkali
- Department of Vitreoretina, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Chaitra Jayadev
- Department of Vitreoretina, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Aishwarya Anuj
- Department of Vitreoretina, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Naresh K Yadav
- Department of Vitreoretina, Narayana Nethralaya, Bangalore, Karnataka, India
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Streese L, Brawand LY, Gugleta K, Maloca PM, Vilser W, Hanssen H. New Frontiers in Noninvasive Analysis of Retinal Wall-to-Lumen Ratio by Retinal Vessel Wall Analysis. Transl Vis Sci Technol 2020; 9:7. [PMID: 32821504 PMCID: PMC7408937 DOI: 10.1167/tvst.9.6.7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/04/2020] [Indexed: 12/14/2022] Open
Abstract
Purpose To compare measurement of wall-to-lumen ratio (WLR) by means of high-resolution adaptive optics imaging (AO) with intuitive to use retinal vessel wall (VW) analysis (VWA). Moreover, to validate the techniques by comparing WLR of healthy young (HY) with healthy older patients. Methods Ten retinal VW images of 13 HY (24 ± 2 years) and 16 healthy older (60 ± 8 years) were obtained with AO and VWA. The average of five measurements of VW, retinal vessel lumen and WLR of a single vessel from AO and VWA were calculated and compared. Results WLR of AO and VWA images showed high correlations, r = 0.75, t(27) = 5.98, P < .001, but differed systematically (WLR: VWA, 40 ± 7% and AO, 35 ± 9%; P < .001). Comparable patterns were found for VW and vessel lumen. HY showed significantly lower WLR (AO, 31 ± 8% and VWA, 36 ± 8%) compared with healthy older (AO, 39 ± 9% [P = .012]; VWA, 42 ± 5% [P = .013]). Conclusions Assessment of WLR by VWA showed a good correlation with laborious analysis of the microstructure by high-resolution AO. Measurement of WLR in different age groups indicated good validity. Deviations in VW, vessel lumen, and WLR between AO and VWA can be explained by systematic differences in image scale and resolution. Future studies are needed to investigate the clinical relevance of microvascular WLR assessment by retinal VWA and its prognostic value. Translational Relevance Additional assessment of retinal WLR by use of digital VWA to evaluate microstructural remodeling may prove to be a valuable extension to the current use of retinal vessel diameters as biomarkers of cardiovascular risk.
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Affiliation(s)
- Lukas Streese
- Department of Sport, Exercise and Health, Medical Faculty, University of Basel, Basel, Switzerland
| | - Lukas Y Brawand
- Department of Sport, Exercise and Health, Medical Faculty, University of Basel, Basel, Switzerland
| | | | - Peter M Maloca
- Department of Ophthalmology, University of Basel, Basel, Switzerland.,Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Moorfields Eye Hospital, London, UK
| | - Walthard Vilser
- Institute of Biomedical Engineering and Informatics, Technical University of Ilmenau, Ilmenau, Germany
| | - Henner Hanssen
- Department of Sport, Exercise and Health, Medical Faculty, University of Basel, Basel, Switzerland
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Retinal arteriolar wall-to-lumen ratios at 16–17 years in the Copenhagen Child Cohort 2000 Study. J Hypertens 2020; 38:731-736. [DOI: 10.1097/hjh.0000000000002329] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Comparison between invasive and noninvasive techniques of evaluation of microvascular structural alterations. J Hypertens 2019; 36:1154-1163. [PMID: 29578964 DOI: 10.1097/hjh.0000000000001677] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND The evaluation of the morphological characteristics of small resistance arteries in humans is challenging. The gold standard method is generally considered to be the measurement by wire or pressure micromyography of the media-to-lumen ratio of subcutaneous small vessels obtained by local biopsies. However, noninvasive techniques for the evaluation of retinal arterioles were recently proposed; in particular, two approaches, scanning laser Doppler flowmetry (SLDF) and adaptive optics, seem to provide useful information; both of them provide an estimation of the wall-to-lumen ratio (WLR) of retinal arterioles. Moreover, a noninvasive measurement of basal and total capillary density may be obtained by videomicroscopy/capillaroscopy. No direct comparison of these three noninvasive techniques in the same population was previously performed; in particular, adaptive optics was never validated against micromyography. METHODS In the current study, we enrolled 41 controls and patients: 12 normotensive lean controls, 12 essential hypertensive lean patients, nine normotensive obese patients and eight hypertensive obese patients undergoing elective surgery. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance artery structure was assessed by wire micromyography and the media-to-lumen ratio was calculated. WLR of retinal arterioles was obtained by SLDF and adaptive optics. Functional (basal) and structural (total) microvascular density was evaluated by capillaroscopy before and after venous congestion. RESULTS AND CONCLUSION Our data suggest that adaptive optics has a substantial advantage over SLDF in terms of evaluation of microvascular morphology, as WLR measured with adaptive optics is more closely correlated with the M/L of subcutaneous small arteries (r = 0.84, P < 0.001 vs. r = 0.52, P < 0.05, slopes of the relations: P < 0.01 adaptive optics vs. SLDF). In addition, the reproducibility of the evaluation of the WLR with adaptive optics is far better, as compared with SLDF, as intraobserver and interobserver variation coefficients are clearly smaller. This may be important in terms of clinical evaluation of microvascular morphology in a clinical setting, as micromyography has substantial limitations in its clinical application due to the local invasiveness of the procedure.
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Gofas-Salas E, Mecê P, Mugnier L, Bonnefois AM, Petit C, Grieve K, Sahel J, Paques M, Meimon S. Near infrared adaptive optics flood illumination retinal angiography. BIOMEDICAL OPTICS EXPRESS 2019; 10:2730-2743. [PMID: 31259047 PMCID: PMC6583347 DOI: 10.1364/boe.10.002730] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/06/2018] [Accepted: 12/22/2018] [Indexed: 05/06/2023]
Abstract
Image-based angiography is a well-adapted technique to characterize vasculature, and has been used in retinal neurovascular studies. Because the microvasculature is of particular interest, being the site of exchange between blood and tissue, a high spatio-temporal resolution is required, implying the use of adaptive optics ophthalmoscopes with a high frame rate. Creating the opportunity for decoupled stimulation and imaging of the retina makes the use of near infrared (NIR) imaging light desirable, while the need for a large field of view and a lack of distortion implies the use of a flood illumination-based setup. However, flood-illumination NIR video sequences of erythrocytes, or red blood cells (RBC), have a limited contrast compared to scanning systems and visible light. As a result, they cannot be processed via existing image-based angiography methods. We have therefore developed a new computational method relying on a spatio-temporal filtering of the sequence to isolate blood flow from noise in low-contrast sequences. Applying this computational approach enabled us to perform angiography with an adaptive optics flood illumination ophthalmoscope (AO-FIO) using NIR light, both in bright-field and dark-field modalities. Finally, we demonstrate the capabilities of our system to differentiate blood flow velocity on a retinal capillary network in vivo.
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Affiliation(s)
- Elena Gofas-Salas
- DOTA, ONERA, Université Paris Saclay, F-91123 Palaiseau,
France
- Institut de la Vision, 17 rue Moreau, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 75012 Paris,
France
- PARIS Group - Paris Adaptive-Optics for Retinal Imaging and Surgery, Paris,
France
| | - Pedro Mecê
- DOTA, ONERA, Université Paris Saclay, F-91123 Palaiseau,
France
- PARIS Group - Paris Adaptive-Optics for Retinal Imaging and Surgery, Paris,
France
- Quantel Medical, Cournon d’Auvergne,
France
| | - Laurent Mugnier
- DOTA, ONERA, Université Paris Saclay, F-91123 Palaiseau,
France
| | | | - Cyril Petit
- DOTA, ONERA, Université Paris Saclay, F-91123 Palaiseau,
France
- PARIS Group - Paris Adaptive-Optics for Retinal Imaging and Surgery, Paris,
France
| | - Kate Grieve
- Institut de la Vision, 17 rue Moreau, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 75012 Paris,
France
- PARIS Group - Paris Adaptive-Optics for Retinal Imaging and Surgery, Paris,
France
- CIC 1423, INSERM, Quinze-Vingts Hospital, Paris,
France
| | - José Sahel
- Institut de la Vision, 17 rue Moreau, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 75012 Paris,
France
- Quantel Medical, Cournon d’Auvergne,
France
- CIC 1423, INSERM, Quinze-Vingts Hospital, Paris,
France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA,
USA
| | - Michel Paques
- Institut de la Vision, 17 rue Moreau, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 75012 Paris,
France
- PARIS Group - Paris Adaptive-Optics for Retinal Imaging and Surgery, Paris,
France
- CIC 1423, INSERM, Quinze-Vingts Hospital, Paris,
France
| | - Serge Meimon
- DOTA, ONERA, Université Paris Saclay, F-91123 Palaiseau,
France
- PARIS Group - Paris Adaptive-Optics for Retinal Imaging and Surgery, Paris,
France
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Burns SA, Elsner AE, Sapoznik KA, Warner RL, Gast TJ. Adaptive optics imaging of the human retina. Prog Retin Eye Res 2019; 68:1-30. [PMID: 30165239 PMCID: PMC6347528 DOI: 10.1016/j.preteyeres.2018.08.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 12/18/2022]
Abstract
Adaptive Optics (AO) retinal imaging has provided revolutionary tools to scientists and clinicians for studying retinal structure and function in the living eye. From animal models to clinical patients, AO imaging is changing the way scientists are approaching the study of the retina. By providing cellular and subcellular details without the need for histology, it is now possible to perform large scale studies as well as to understand how an individual retina changes over time. Because AO retinal imaging is non-invasive and when performed with near-IR wavelengths both safe and easily tolerated by patients, it holds promise for being incorporated into clinical trials providing cell specific approaches to monitoring diseases and therapeutic interventions. AO is being used to enhance the ability of OCT, fluorescence imaging, and reflectance imaging. By incorporating imaging that is sensitive to differences in the scattering properties of retinal tissue, it is especially sensitive to disease, which can drastically impact retinal tissue properties. This review examines human AO retinal imaging with a concentration on the use of the Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO). It first covers the background and the overall approaches to human AO retinal imaging, and the technology involved, and then concentrates on using AO retinal imaging to study the structure and function of the retina.
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Affiliation(s)
- Stephen A Burns
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States.
| | - Ann E Elsner
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Kaitlyn A Sapoznik
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Raymond L Warner
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
| | - Thomas J Gast
- 800E. Atwater S, School of Optometry, Indiana University, Bloomington, IN, United States
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Adaptive optics ophthalmoscopy: Application to age-related macular degeneration and vascular diseases. Prog Retin Eye Res 2018; 66:1-16. [DOI: 10.1016/j.preteyeres.2018.07.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 07/12/2018] [Accepted: 07/12/2018] [Indexed: 12/11/2022]
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Rizzoni D, Agabiti Rosei C, De Ciuceis C, Semeraro F, Rizzoni M, Docchio F. New Methods to Study the Microcirculation. Am J Hypertens 2018; 31:265-273. [PMID: 29228086 DOI: 10.1093/ajh/hpx211] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Essential hypertension is associated with structural alterations in the microvessels; in particular, an increase in the media thickness to internal lumen ratio of small resistance arteries (MLR) and a reduction in capillary density have been observed. The evaluation of the morphological characteristics of small resistance arteries in humans is challenging. The gold-standard method is generally considered to be the measurement by wire or pressure micromyography of MLR of subcutaneous small vessels obtained by local biopsies. However, noninvasive techniques for the evaluation of retinal arterioles were recently proposed; in particular, 2 approaches, scanning laser Doppler flowmetry (SLDF) and adaptive optics (AO), seem to provide useful information. Both of them provide an estimation of the wall to lumen ratio (WLR) of retinal arterioles. Moreover, a noninvasive measurement of basal and total capillary density may be obtained by videomicroscopy/capillaroscopy. It has been recently demonstrated that AO has a substantial advantage over SLDF in terms of evaluation of microvascular morphology, since WLR measured with AO is more closely correlated with the M/L of subcutaneous small arteries. The possibility to noninvasively assess in a reliable way, microvascular morphology in a clinical setting may represent a major advancement, since micromyography has substantial limitations in its application due to the local invasiveness of the procedure.
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Affiliation(s)
- Damiano Rizzoni
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Istituto Clinico Città di Brescia, Division of Medicine, Brescia, Italy
| | - Claudia Agabiti Rosei
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Carolina De Ciuceis
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Francesco Semeraro
- Eye Clinic, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Marco Rizzoni
- Department of Information Engineering, University of Brescia, Brescia, Italy
| | - Franco Docchio
- Department of Mechanical and Industrial Engineering, University of Brescia, Brescia, Italy
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Zaleska-Żmijewska A, Piątkiewicz P, Śmigielska B, Sokołowska-Oracz A, Wawrzyniak ZM, Romaniuk D, Szaflik J, Szaflik JP. Retinal Photoreceptors and Microvascular Changes in Prediabetes Measured with Adaptive Optics (rtx1™): A Case-Control Study. J Diabetes Res 2017; 2017:4174292. [PMID: 29238728 PMCID: PMC5697118 DOI: 10.1155/2017/4174292] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/15/2017] [Accepted: 09/28/2017] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Patients with prediabetes are at risk for diabetes, cardiovascular events, and microvascular complications. The rtx1 (Imagine Eyes, France) permits early detection of changes in the retinal photoreceptors and vessels. OBJECTIVE Cone parameters and retinal microvasculature were analyzed with the rtx1 in 12 prediabetic patients and 22 healthy subjects. The analysis was based on cone density (DM), interphotoreceptor distance (SM), cone packing regularity, and retinal vessel parameters: wall thickness, lumen diameter (LD), wall-to-lumen ratio (WLR), and cross-sectional area of the vascular wall. RESULTS DM in the prediabetic group was not significantly lower than that in the control group (18,935 ± 1713 cells/mm2 and 19,900 ± 2375 cells/mm2, respectively; p = 0.0928). The LD and WLR means differed significantly between the prediabetic and the control groups (LD 94.3 ± 10.9 versus 101.2 ± 15, p = 0.022; WLR 0.29 ± 0.05 versus 0.22 ± 0.03, p < 0.05). A multivariate regression analysis showed that the WLR was significantly correlated with BMI and total cholesterol. CONCLUSIONS Abnormalities found in rtx1 examinations indicated early signs of arteriolar dysfunction, prior to impaired glucose tolerance progressing to diabetes. The rtx1 retinal image analysis offers noninvasive measurement of early changes in the vasculature that routine clinical examination cannot detect.
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Affiliation(s)
- Anna Zaleska-Żmijewska
- Department of Ophthalmology, SPKSO Ophthalmic Hospital, Medical University of Warsaw, Warsaw, Poland
| | - Paweł Piątkiewicz
- Department of Internal Diseases, Diabetology and Endocrinology, Medical University of Warsaw, Warsaw, Poland
| | - Barbara Śmigielska
- Department of Ophthalmology, SPKSO Ophthalmic Hospital, Medical University of Warsaw, Warsaw, Poland
| | - Anna Sokołowska-Oracz
- Department of Internal Diseases, Diabetology and Endocrinology, Medical University of Warsaw, Warsaw, Poland
- Retinopathy Outpatient Clinic, Masovian Hospital Bródno, Warsaw, Poland
| | - Zbigniew M. Wawrzyniak
- Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - Dorota Romaniuk
- Department of Ophthalmology, SPKSO Ophthalmic Hospital, Warsaw, Poland
| | - Jerzy Szaflik
- Department of Ophthalmology, SPKSO Ophthalmic Hospital, Medical University of Warsaw, Warsaw, Poland
| | - Jacek P. Szaflik
- Department of Ophthalmology, SPKSO Ophthalmic Hospital, Medical University of Warsaw, Warsaw, Poland
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Kannenkeril D, Harazny JM, Bosch A, Ott C, Michelson G, Schmieder RE, Friedrich S. Retinal vascular resistance in arterial hypertension. Blood Press 2017; 27:82-87. [PMID: 29057671 DOI: 10.1080/08037051.2017.1393311] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Retinal microcirculation represents an easily accessible, non-invasive, in-vivo possibility to assess early microvascular changes. In addition to the assessment of functional (e.g. retinal capillary flow, RCF) and retinal arteriolar structural parameters (e.g. wall-to-lumen-ratio, WLR) we now suggest a new parameter reflecting the resistance in small retinal arterioles (RVR). MATERIAL AND METHODS In 45 normotensive (NT) subjects and 123 patients with hypertension stage 1 (HT) we assessed RCF, WLR, arteriolar diameter, lumen diameter and wall cross section area in the retinal circulation by using scanning laser Doppler flowmetry (SLDF). Mean arterial pressure (MAP) was measured immediately before the SLDF measurement and retinal vascular resistance was calculated (RVR = MAP/RCF). In a separate study the test-retest reliability was determined in 6 volunteers from our clinical staff by assessing RVR three times within six weeks. RESULTS The analysis of the volunteers revealed a coefficient of variation for RVR of 7.75 ± 2.11% and Cronbach´s alpha was 0.90. WLR, a marker of vascular remodeling did not differ between NT and HT. In contrast, RCF and inner diameter of the retinal arterioles (ID) were significantly lower (RCF: p = .045 and ID: p = .001) in the HT group than in the NT group and RVR was significantly higher in the HT group than in the NT group (p < .001). In both groups we found no correlation of RVR with age, but a significant correlation of RVR with WLR (NT: r = 0.34, p = .006; HT: r = 0.25, p = .01), indicating that the RVR reflects vascular remodeling in the retinal circulation. CONCLUSION Our data showed an increased retinal vascular resistance in hypertensive patients compared to non-hypertensive patients prior to the occurrence of structural retinal vascular remodeling. The correlation between RVR and WLR indicates that RVR is a reliable, non-invasive and early-sensitive marker of vascular remodeling in early hypertension.
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Affiliation(s)
- Dennis Kannenkeril
- a Department of Nephrology and Hypertension , University Hospital of the University of Erlangen-Nuremberg , Erlangen , Germany
| | - Joanna M Harazny
- a Department of Nephrology and Hypertension , University Hospital of the University of Erlangen-Nuremberg , Erlangen , Germany.,b Department of Pathophysiology , University of Warmia and Mazury , Olsztyn , Poland
| | - Agnes Bosch
- a Department of Nephrology and Hypertension , University Hospital of the University of Erlangen-Nuremberg , Erlangen , Germany
| | - Christian Ott
- a Department of Nephrology and Hypertension , University Hospital of the University of Erlangen-Nuremberg , Erlangen , Germany
| | - Georg Michelson
- c Department of Ophthalmology , University of Erlangen-Nuremberg , Erlangen , Germany
| | - Roland E Schmieder
- a Department of Nephrology and Hypertension , University Hospital of the University of Erlangen-Nuremberg , Erlangen , Germany
| | - Stefanie Friedrich
- a Department of Nephrology and Hypertension , University Hospital of the University of Erlangen-Nuremberg , Erlangen , Germany
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Wei Y, Jiang H, Shi Y, Qu D, Gregori G, Zheng F, Rundek T, Wang J. Age-Related Alterations in the Retinal Microvasculature, Microcirculation, and Microstructure. Invest Ophthalmol Vis Sci 2017; 58:3804-3817. [PMID: 28744554 PMCID: PMC5527847 DOI: 10.1167/iovs.17-21460] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Purpose To characterize age-related alterations in the retinal microcirculation, microvascular network, and microstructure in healthy subjects. Methods Seventy-four healthy subjects aged from 18 to 82 years were recruited and divided into four age groups (G1 with age <35 years, G2 with age 35 ∼ 49 years, G3 with age 50 ∼ 64 years, and G4 with age ≥65 years). Custom ultra-high resolution optical coherence tomography (UHR-OCT) was used to acquire six intraretinal layers of the macula. OCT angiography (OCTA) was used to image the retinal microvascular network. The retinal blood flow velocity (BFV) was measured using a Retinal Function Imager (RFI). Results Compared to G1, G2 had significant thinning of the retinal nerve fiber layer (RNFL) (P < 0.05), while G3 had thinning of the RNFL and ganglion cell and inner plexiform layer (GCIPL) (P < 0.05), in addition to thickening of the outer plexiform layer (OPL) and photoreceptor layer (PR) (P < 0.05). G4 had loss in retinal vessel density, thinning in RNFL and GCIPL, and decrease in venular BFV, in addition to thickening of the OPL and PR (P < 0.05). Age was negatively related to retinal vessel densities, the inner retinal layers, and venular BFV (P < 0.05). By contrast, age was positively related to OPL and PR (P < 0.05). Conclusions During aging, decreases in retinal vessel density, inner retinal layer thickness, and venular BFV were evident and impacted each other as observed by simultaneous changes in multiple retinal components.
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Affiliation(s)
- Yantao Wei
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China,Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Hong Jiang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States,Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Yingying Shi
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Dongyi Qu
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Giovanni Gregori
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Fang Zheng
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Tatjana Rundek
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Jianhua Wang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
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Abstract
PURPOSE OF REVIEW Hypertension is the primary risk factor for cardiovascular disease and mortality that consists a major public health issue worldwide. Hypertension triggers a series of pathophysiological ocular modifications affecting significantly the retinal, choroidal, and optic nerve circulations that result in a range of ocular effects.The retina is the only place in the body where microvasculature can be directly inspected, providing valuable information on hypertension related systemic risks.The aim of this review is to provide an update on latest advances regarding the detection and significance of hypertension related eye signs. RECENT FINDINGS It's been shown that measurable retinal microvascular changes may precede progression of systemic microvascular disease.Last years, there are emerging advances in the field retinal imaging and computer software analysis that have enabled the objective and accurate assessment of retinal vascular caliber, while in association with latest epidemiological studies several other retinal vascular features have been recognized, such as vascular length-to-diameter ratio, and wall-to-lumen ratio that may also be associated to hypertension.Additionally, recent genetic studies have provided some insight to vascular pathophysiological processes having correlated new chromosome's loci to hypertensive retinopathy signs. SUMMARY Assessment of hypertensive retinopathy signs may convey additional prognostic information on the risk of end-organ damage and may alert for urgent systemic management or even preventive systemic therapies. Further development of retinal vascular imaging and computerized system may provide a significant tool to improve the diagnosis, prognosis, and management of hypertension in clinical practice.
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Gallo A, Mattina A, Rosenbaum D, Koch E, Paques M, Girerd X. Retinal arteriolar remodeling evaluated with adaptive optics camera: Relationship with blood pressure levels. Ann Cardiol Angeiol (Paris) 2016; 65:203-207. [PMID: 27184511 DOI: 10.1016/j.ancard.2016.04.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 04/20/2016] [Indexed: 06/05/2023]
Abstract
AIM To research a retinal arterioles wall-to-lumen ratio or lumen diameter cut-off that would discriminate hypertensive from normal subjects using adaptive optics camera. PATIENTS AND METHODS One thousand and five hundred subjects were consecutively recruited and Adaptive Optics Camera rtx1™ (Imagine-Eyes, Orsay, France) was used to measure wall thickness, internal diameter, to calculate wall-to-lumen ratio (WLR) and wall cross-sectional area of retinal arterioles. Sitting office blood pressure was measured once, just before retinal measurements and office blood pressure was defined as systolic blood pressure>=140mmHg and diastolic blood pressure>=90mmHg. ROC curves were constructed to determine cut-off values for retinal parameters to diagnose office hypertension. In another population of 276 subjects office BP, retinal arterioles evaluation and home blood pressure monitoring were obtained. The applicability of retinal WLR or diameter cut-off values were compared in patients with controlled, masked, white-coat and sustained hypertension. RESULTS In 1500 patients, a WLR>0.31 discriminated office hypertensive subjects with a 0.57 sensitivity and 0.71 specificity. Lumen diameter<78.2μm discriminated office hypertension with a 0.73 sensitivity and a 0.52 specificity. In the other 276 patients, WLR was higher in sustained hypertension vs normotensive patients (0.330±0.06 vs 0.292±0.05; P<0.001) and diameter was narrower in masked hypertensive vs normotensive subjects (73.0±11.2 vs 78.5±11.6μm; P<0.005). CONCLUSION A WLR higher than 0.31 is in favour of office arterial hypertension; a diameter under<78μm may indicate a masked hypertension. Retinal arterioles analysis through adaptive optics camera may help the diagnosis of arterial hypertension, in particular in case of masked hypertension.
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Affiliation(s)
- A Gallo
- Preventive Cardiovascular Unit, Institute of Cardiometabolism and Nutrition, Unité de Prévention Cardiovasculaire, Service d'Endocrinologie Métabolisme, Groupe Hospitalier Pitié-Salpêtrière, Assistance publique-Hôpitaux de Paris, 83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Sorbonne Universités, UPMC Université Paris 06, Inserm 1146,-CNRS 7371, Laboratoire d'imagerie biomédicale, 75013 Paris, France
| | - A Mattina
- Preventive Cardiovascular Unit, Institute of Cardiometabolism and Nutrition, Unité de Prévention Cardiovasculaire, Service d'Endocrinologie Métabolisme, Groupe Hospitalier Pitié-Salpêtrière, Assistance publique-Hôpitaux de Paris, 83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Sorbonne Universités, UPMC Université Paris 06, Inserm 1146,-CNRS 7371, Laboratoire d'imagerie biomédicale, 75013 Paris, France
| | - D Rosenbaum
- Preventive Cardiovascular Unit, Institute of Cardiometabolism and Nutrition, Unité de Prévention Cardiovasculaire, Service d'Endocrinologie Métabolisme, Groupe Hospitalier Pitié-Salpêtrière, Assistance publique-Hôpitaux de Paris, 83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Sorbonne Universités, UPMC Université Paris 06, Inserm 1146,-CNRS 7371, Laboratoire d'imagerie biomédicale, 75013 Paris, France; Imaging Core Lab, Institute of Cardiometabolism and Nutrition, ICAN, 75013 Paris, France.
| | - E Koch
- Unité Inserm 968, Institut de la vision - Centre d'Investigation Clinique 503, Centre Hospitalier National des Quinze-Vingts, Assistance publique-Hôpitaux de Paris, 75012 Paris, France
| | - M Paques
- Unité Inserm 968, Institut de la vision - Centre d'Investigation Clinique 503, Centre Hospitalier National des Quinze-Vingts, Assistance publique-Hôpitaux de Paris, 75012 Paris, France
| | - X Girerd
- Preventive Cardiovascular Unit, Institute of Cardiometabolism and Nutrition, Unité de Prévention Cardiovasculaire, Service d'Endocrinologie Métabolisme, Groupe Hospitalier Pitié-Salpêtrière, Assistance publique-Hôpitaux de Paris, 83, boulevard de l'Hôpital, 75651 Paris cedex 13, France
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Effects of age, blood pressure and antihypertensive treatments on retinal arterioles remodeling assessed by adaptive optics. J Hypertens 2016; 34:1115-22. [DOI: 10.1097/hjh.0000000000000894] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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