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Zhao L, Zhang B, Wang J, Yang J, Du L, Wang T, Xu X, He X, Chen J. Short-term effects of sunlight exposure on fundus blood flow perfusion in children: a randomised controlled trial. Br J Ophthalmol 2024:bjo-2024-325715. [PMID: 38981665 DOI: 10.1136/bjo-2024-325715] [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: 04/21/2024] [Accepted: 06/23/2024] [Indexed: 07/11/2024]
Abstract
AIM To evaluate the short-term effects of different sunlight exposure on fundus blood flow perfusion (BFP) after near work. METHODS In this parallel randomised controlled trial, 81 students aged 7-15 with spherical equivalent refraction between -2.00 and +3.00 diopters were randomly assigned to either a low-illuminance (4k lux) group (N=40) or high-illuminance (10k lux) (N=41). Following 1 hour indoor reading, participants had sunlight exposure matching their group's intensity for 15 minutes. BFPs in the superficial retina, deep retina and choroid were measured at four time points: pre-reading, post-reading, 5th-minute and 15th-minute sunlight exposure. RESULTS Within the initial 5 minutes of sunlight exposure, the 10k lux group showed a tendency for decreased BFP, particularly in the choroid (superficial retina: -0.2, 95% CI -0.9 to 0.5; deep retina: -0.1, 95% CI -0.6 to 0.4; choroid: -0.4, 95% CI -0.8 to 0.0), while the 4k lux group exhibited an increase (superficial retina: 0.7, 95% CI 0.1 to 1.3; deep retina: 0.3, 95% CI -0.2 to 0.8; choroid: 0.1, 95% CI -0.2 to 0.5). From 5 to 15 minutes, BFP decreased in both groups. At the 5th-minute mark, the 10k lux group exhibited a greater decrease in choroid (10k -0.4 vs 4k 0.1, p=0.051). No significant difference was observed after 15 minutes of exposure. CONCLUSION Higher illuminance sunlight exposure can restore fundus BFP more rapidly than lower; however, duration remains pivotal. To prevent myopia, continuous sunlight exposure for over 15 minutes is recommended to aid in reinstating the fundus BFP increased by near work. TRIAL REGISTRATION NUMBER NCT05594732.
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Affiliation(s)
- Lingyi Zhao
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, Shanghai, China
| | - Bo Zhang
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
| | - Jingjing Wang
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
| | - Jinliuxing Yang
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
| | - Linlin Du
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
| | - Tianxiao Wang
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
| | - Xun Xu
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, Shanghai, China
| | - Xiangui He
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, Shanghai, China
| | - Jun Chen
- Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, School of Medicine, Tongji University, Shanghai, Shanghai, China
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Masís Solano M, Richer E, Costantino S, Lesk MR. Optic Nerve Head Pulsatile Displacement in Open-Angle Glaucoma after Intraocular Pressure Reduction Measured by Optical Coherence Tomography: A Pilot Study. Bioengineering (Basel) 2024; 11:411. [PMID: 38790278 PMCID: PMC11118210 DOI: 10.3390/bioengineering11050411] [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: 03/05/2024] [Revised: 04/17/2024] [Accepted: 04/22/2024] [Indexed: 05/26/2024] Open
Abstract
This study investigated the effect of intraocular pressure (IOP) reduction on pulsatile displacement within the optic nerve head (ONH) in primary open-angle glaucoma (POAG) patients with and without axial myopia. Forty-one POAG patients (19 without myopia, 9 with axial myopia and 13 glaucoma with no intervention) participated. Swept-source optical coherence tomography (OCT) videos of the ONH were obtained before and after IOP-lowering treatment (medical or surgical) achieving a minimum IOP drop of 3 mmHg. A demons registration-based algorithm measured local pulsatile displacement maps within the ONH. Results demonstrated a significant 14% decrease in pulsatile tissue displacement in the non-myopic glaucoma cohort after intervention (p = 0.03). However, glaucoma patients with axial myopia exhibited no statistically significant change. There were no significant changes in the pulsatile ONH deformation in the control group. These findings suggest a potential link between IOP reduction and reduced pulsatile displacement within the ONH in POAG patients without myopia, offering new insights into the disease's pathophysiology and warranting further investigation into underlying mechanisms and clinical implications.
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Affiliation(s)
- Marissé Masís Solano
- Maisonneuve-Rosemont Hospital Research Center, 5415 Assumption Blvd, Montreal, QC H1T 2M4, Canada
- Department of Ophthalmology, Université de Montréal, 5415 Assumption Blvd, Montreal, QC H1T 2M4, Canada
| | - Emmanuelle Richer
- Maisonneuve-Rosemont Hospital Research Center, 5415 Assumption Blvd, Montreal, QC H1T 2M4, Canada
- École Polytechnique de Montréal, 2500 Chemin de Polytechnique, Montreal, QC H3T 1J4, Canada
| | - Santiago Costantino
- Maisonneuve-Rosemont Hospital Research Center, 5415 Assumption Blvd, Montreal, QC H1T 2M4, Canada
- Department of Ophthalmology, Université de Montréal, 5415 Assumption Blvd, Montreal, QC H1T 2M4, Canada
| | - Mark R. Lesk
- Maisonneuve-Rosemont Hospital Research Center, 5415 Assumption Blvd, Montreal, QC H1T 2M4, Canada
- Department of Ophthalmology, Université de Montréal, 5415 Assumption Blvd, Montreal, QC H1T 2M4, Canada
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Wu JY, Hu JY, Ge QM, Xu SH, Zou J, Kang M, Ying P, Wei H, Ling Q, He LQ, Chen C, Shao Y. Ocular microvascular alteration in patients with myocardial infarction-a new OCTA study. Sci Rep 2024; 14:4552. [PMID: 38402285 PMCID: PMC10894220 DOI: 10.1038/s41598-023-50283-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/18/2023] [Indexed: 02/26/2024] Open
Abstract
Myocardial infarction is defined as a sudden decrease or interruption in blood flow to the coronary arteries, causing ischemic necrosis of the corresponding cardiomyocytes. It is unclear whether systemic macrovascular alterations are associated with retinal microvascular changes. This study utilized optical coherence tomography angiography (OCTA) to compare variations in conjunctival vascular density and fundus retinal vessel density between patients with myocardial infarction (MI) and healthy controls. This study recruited 16 patients (32 eyes) with MI and 16 healthy controls (32 eyes). The superficial retinal layer (SRL), deep retinal layer (DRL) and conjunctival capillary plexus in each eye were evaluated by OCTA. Parameters measured included the density of the temporal conjunctival capillary, retinal microvascular (MIR) and macrovascular (MAR) alterations and total MIR (TMI). The microvascular density of each retinal region was evaluated by the hemisphere segmentation (SR, SL, IL, and IR), annular partition (C1, C2, C3, C4, C5 and C6), and modified early treatment of diabetic retinopathy study (R, S, L, and I) methods. In the macular area, the superficial and deep retinal microvascular densities displayed notable variations. In the superficial layers, the superficial TMI, superficial MIR, and superficial MAR, as well as densities in the SL, IL, S, L, C1, C2, C5 and C6 regions, were significantly lower in MI patients (p < 0.05 each). In the deep layers, the deep MIR and deep TMI), as well as densities in the SL, IL, L, C1, C2 and C6 regions were significantly lower in MI patients (p < 0.05 each). In contrast, the conjunctival microvascular density was significantly higher in MI patients than in healthy controls (p < 0.001). The microvascular densities measured in the deep and superficial retinal layers and in the conjunctiva differ in MI patients and healthy controls. OCTA is effective in detecting changes in the ocular microcirculation.
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Affiliation(s)
- Jun-Yi Wu
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Jin-Yu Hu
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Qian-Min Ge
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - San-Hua Xu
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Jie Zou
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Min Kang
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Ping Ying
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Hong Wei
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Qian Ling
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Liang-Qi He
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Cheng Chen
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Yi Shao
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, 200030, China.
- Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, 330006, Jiangxi, China.
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Meng L, Chen L, Zhang C, Chen H, Yang J, Wang Y, Zhang W, Cheng S, Zhao Q, Zhao X, Chen Y. Quantitative assessment of retinal vasculature changes in systemic lupus erythematosus using wide-field OCTA and the correlation with disease activity. Front Immunol 2024; 15:1340224. [PMID: 38348025 PMCID: PMC10859513 DOI: 10.3389/fimmu.2024.1340224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 01/08/2024] [Indexed: 02/15/2024] Open
Abstract
Purpose To assess the retinal vasculature changes quantitatively using wide-field optical coherence tomography angiography (OCTA) in systemic lupus erythematosus (SLE), and explore its correlation with systemic clinical features. Design Prospective, cross-sectional, observational study. Participants and controls Patients with SLE who presented to the Ophthalmology Department of Peking Union Medical College Hospital from November 2022 to April 2023 were collected. The subjects were divided into retinopathy and without retinopathy groups. Age and gender-matched healthy subjects were selected as controls. Methods Patients with SLE and control subjects were imaged with 24×20 mm OCTA scans centered on the fovea and 6×6 mm OCTA scans centered on the optic disc. The sub-layers of OCTA images were stratified by the built-in software of the device and then the retinal thickness and vessel density were measured automatically. The characteristics of retinal OCTA parameters of SLE and its correlation with systemic clinical indicators of patients without retinopathy were analyzed. Main outcome measures OCTA parameters, visual acuity, intraocular pressure, and systemic clinical indicators of patients such as disease activity index, autoimmune antibodies, and inflammatory marker levels were collected. Results A total of 102 SLE patients were included, 24 of which had retinopathy, and 78 had unaffected retina. Wide-field OCTA could effectively detect retinal vascular obstruction, non-perfusion area, and morphological abnormalities in patients with lupus retinopathy. SLE patients without retinopathy had significantly higher retinal superficial vessel density (SVD) in foveal (P=0.02), para-foveal temporal (P=0.01), nasal (P=0.01), peripheral foveal temporal (P=0.02), and inferior areas (P=0.02), as well as subregion temporal (P=0.01) and inferior areas (P=0.03) when compared with healthy controls (n=65 eyes from 65 participants). The area under curve (AUC) value of subregion inferior SVD combined parafoveal temporal SVD was up to 0.70. There was a significantly positive correlation between SVD and disease activity in SLE without retinopathy group. Patients with severe activity had the most significant increase in SVD. Conclusion Wide-field OCTA can provide a relatively comprehensive assessment of the retinal vasculature in SLE. In the absence of pathological changes of the retina, the SVD was significantly increased and was positively correlated with the disease activity of SLE.
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Affiliation(s)
- Lihui Meng
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lulu Chen
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Chenxi Zhang
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huan Chen
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jingyuan Yang
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuelin Wang
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wenfei Zhang
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shiyu Cheng
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qing Zhao
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xinyu Zhao
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Youxin Chen
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Zhao Y, Zou H, Fan W, Liu Y, Chen X, Huang Y, Yuan R. Patterns of Structural Changes in the Fundus Measured by Optical Coherence Tomography Angiography as Potential Markers of Acute Mountain Sickness. Transl Vis Sci Technol 2023; 12:15. [PMID: 38088829 PMCID: PMC10720760 DOI: 10.1167/tvst.12.12.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/03/2023] [Indexed: 12/17/2023] Open
Abstract
Purpose To use optical coherence tomography angiography (OCTA) to assess the pattern of changes in retinal and choroidal blood flow and structure in healthy volunteers who quickly went from sea level to a plateau and to determine the parameters associated with acute mountain sickness (AMS). Methods Forty-five individuals (89 eyes) were examined by OCTA and filled out the AMS questionnaire. One baseline examination was performed on the plain, followed by examinations at days 1, 3, and 5 after entering the plateau. Parameters were self-controlled to explore patterns of change, analyzed for correlation with AMS score, and modeled as a nomogram of AMS risk. Results On the plateau compared to the plain, vascular morphology showed dilated superficial macular retinal vessels and constricted deeper layers with increased vessel length density and fractal dimension; vessel density increased in all retinal strata and decreased in the choroidal macrovascular layer; and thickness increased except for a decrease in mean retinal thickness in the central macular sulcus. The rate of increase in retinal nerve fiber layer (RNFL) thickness in the inner and outer macular rings correlated with AMS score (r = -0.211). The nomogram showed moderate accuracy (AUC = 0.672) and consistency (C-index = 0.659) in assessing AMS risk. Conclusions In high-altitude hypoxia, retinal vessels dilate and distort, resulting in increased blood flow density and thickness. Increased RNFL thickness in the paracentral macula may be a marker of low AMS risk. Translational Relevance The changes in the retinal structure of the fundus can be used to assess the risk of developing AMS.
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Affiliation(s)
- Yuancheng Zhao
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Huan Zou
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Wei Fan
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Yuqi Liu
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Xiaofan Chen
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Yanming Huang
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Rongdi Yuan
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
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Bajka A, Foa N, Sidhu S, Rejdak M, Said S, Wiest MRJ, Hamann T, Blaser F, Zweifel SA. Analysis of Blood Flow in the Macula and Optic Nerve Head in Healthy Young Volunteers Using Laser Speckle Flowgraphy. Klin Monbl Augenheilkd 2023; 240:608-612. [PMID: 37164413 DOI: 10.1055/a-2026-0924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
PURPOSE To assess optic nerve head (ONH) and macular blood flow in young healthy volunteers using laser speckle flowgraphy (LSFG). METHODS This is a prospective single-center study conducted at the Department of Ophthalmology, University Hospital Zurich from May to November 2021. Young, healthy men aged ≥ 18 years without ocular or systemic diseases were included. A corrected visual acuity (VA) of 0.0 logMAR or better in both eyes and an intraocular pressure (IOP) of 21 mmHg or lower were required for inclusion. Subjects exceeding a spherical equivalent (SE) of ± 6 diopters (dpt) were excluded. Blood flow in the macula and the ONH was recorded using the Nidek LSFG RetFlow device (Nidek Company, Ltd., Hirioshi-cho, Japan). Laser power was set to 0.5 Millivolts (mV). Mean blur rate (MBR) was recorded as a parameter for blood flow. MBR is a calculated parameter that represents relative blood flow velocity correlated with the real anatomical blood flow rate. Colored heat maps of the recorded retinal area were generated automatically by the RetFlow device. RESULTS Final analyses included 83 eyes of 43 male volunteers. Mean age was 21.9 years (SD ± 1.5, range: 20 to 29). Mean corrected VA was - 0.1 logMAR (SD ± 0.05, range: - 0.2 to 0.0), mean IOP was 15.4 mmHg (SD ± 2.5, range: 8.5 to 18.5), and mean SE was - 0.3 dpt (SD ± 1.2, range: - 5.0 to 1.2). Mean ONH MBR was 37.44 (SD ± 7.9, range: 22.5 to 53.5) and mean macular MBR was 27.8 (SD ± 9.7, range: 6.4 to 57.7). Pearson's Test showed a strong correlation between macular and papillary blood flow (p < 0.05, coefficient: 0.647). CONCLUSION This study provides both ONH and macular blood flow data in a healthy young male population, showing a strong correlation between ONH and macular blood flow in the examined eyes. Further investigations are required to assess the validity of MBR as a parameter for the combined evaluation of retinal blood flow at the macula and ONH in healthy volunteers and patients with various diseases.
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Affiliation(s)
- Anahita Bajka
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, Switzerland
| | - Nastasia Foa
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, Switzerland
| | - Sophia Sidhu
- Faculty of Medicine, University of San Diego, San Diego, California, United States
| | - Magdalena Rejdak
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, Switzerland
| | - Sadiq Said
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, Switzerland
| | | | - Timothy Hamann
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, Switzerland
| | - Frank Blaser
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, Switzerland
| | - Sandrine Anne Zweifel
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, Switzerland
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Hommer N, Kallab M, Sim YC, Lee AX, Chua J, Tan B, Schlatter A, Werkmeister RM, Schmidl D, Schmetterer L, Garhöfer G. Effect of hyperoxia and hypoxia on retinal vascular parameters assessed with optical coherence tomography angiography. Acta Ophthalmol 2022; 100:e1272-e1279. [PMID: 34881512 DOI: 10.1111/aos.15077] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/20/2021] [Accepted: 11/29/2021] [Indexed: 01/05/2023]
Abstract
PURPOSE To investigate the response of the superficial and deep capillary plexuses to hyperoxia and hypoxia using optical coherence tomography angiography (OCT-A) and retinal vessel analyzer. METHODS Twenty-four healthy volunteers participated in this randomized, double-masked, cross-over study. For each subject, two study days were scheduled: on one study day, hyperoxia was induced by breathing 100% oxygen whereas on the other study day, hypoxia was induced by breathing a mixture of 88% nitrogen and 12% oxygen. Perfusion density was calculated in the superficial vascular plexus (SVP) and the deep capillary plexus (DCP), using OCT-A before (normal breathing) and during breathing of the gas mixtures. Retinal vessel calibres in major retinal vessels were measured using a dynamic vessel analyzer. RESULTS During 100% oxygen breathing, a significant decrease in DCP perfusion density from 41.7 ± 2.4 a.u to 35.6 ± 3.1 a.u. (p < 0.001) was observed, which was accompanied by a significant decrease in vessel diameters in major retinal arteries and veins (p < 0.001 each). No significant change in perfusion density in the SVP occurred (p = 0.33). In contrast, during hypoxia, perfusion density in the SVP significantly increased from 34.4 ± 3.0 a.u. to 37.1 ± 2.2 a.u. (p < 0.001), while it remained stable in the DCP (p = 0.25). A significant increase in retinal vessel diameters was found (p < 0.01). Systemic oxygen saturation correlated negatively with perfusion density in the SVP and the DCP and retinal vessel diameters (p < 0.005 each). CONCLUSION Our results show that systemic hyperoxia induces a significant decrease in vessel density in the DCP, while hypoxia leads to increased vessel density limited to the SVP. These results indicate that the retinal circulation shows the ability to adapt its blood flow to metabolic changes with high local resolution dependent on the capillary plexus.
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Affiliation(s)
- Nikolaus Hommer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Martin Kallab
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Yin Ci Sim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Ashe Xy Lee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Andreas Schlatter
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,VIROS - Vienna Institute for Research in Ocular Surgery - Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria
| | - René M Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.,Institute of Clinical and Experimental Ophthalmology, Basel, Switzerland
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
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Cheung CMG, Fawzi A, Teo KY, Fukuyama H, Sen S, Tsai WS, Sivaprasad S. Diabetic macular ischaemia- a new therapeutic target? Prog Retin Eye Res 2022; 89:101033. [PMID: 34902545 DOI: 10.1016/j.preteyeres.2021.101033] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/25/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022]
Abstract
Diabetic macular ischaemia (DMI) is traditionally defined and graded based on the angiographic evidence of an enlarged and irregular foveal avascular zone. However, these anatomical changes are not surrogate markers for visual impairment. We postulate that there are vascular phenotypes of DMI based on the relative perfusion deficits of various retinal capillary plexuses and choriocapillaris. This review highlights several mechanistic pathways, including the role of hypoxia and the complex relation between neurons, glia, and microvasculature. The current animal models are reviewed, with shortcomings noted. Therefore, utilising the advancing technology of optical coherence tomography angiography (OCTA) to identify the reversible DMI phenotypes may be the key to successful therapeutic interventions for DMI. However, there is a need to standardise the nomenclature of OCTA perfusion status. Visual acuity is not an ideal endpoint for DMI clinical trials. New trial endpoints that represent disease progression need to be developed before irreversible vision loss in patients with DMI. Natural history studies are required to determine the course of each vascular and neuronal parameter to define the DMI phenotypes. These DMI phenotypes may also partly explain the development and recurrence of diabetic macular oedema. It is also currently unclear where and how DMI fits into the diabetic retinopathy severity scales, further highlighting the need to better define the progression of diabetic retinopathy and DMI based on both multimodal imaging and visual function. Finally, we discuss a complete set of proposed therapeutic pathways for DMI, including cell-based therapies that may provide restorative potential.
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Affiliation(s)
- Chui Ming Gemmy Cheung
- Singapore Eye Research Institution, Singapore National Eye Centre, Singapore; Duke-NUS Medical School, National University of Singapore, Singapore
| | | | - Kelvin Yc Teo
- Singapore Eye Research Institution, Singapore National Eye Centre, Singapore
| | | | | | - Wei-Shan Tsai
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom
| | - Sobha Sivaprasad
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom.
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9
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Baker J, Safarzadeh MA, Incognito AV, Jendzjowsky NG, Foster GE, Bird JD, Raj SR, Day TA, Rickards CA, Zubieta-DeUrioste N, Alim U, Wilson RJA. Functional optical coherence tomography at altitude: retinal microvascular perfusion and retinal thickness at 3,800 meters. J Appl Physiol (1985) 2022; 133:534-545. [PMID: 35771223 DOI: 10.1152/japplphysiol.00132.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cerebral hypoxia is a serious consequence of several cardiorespiratory illnesses. Measuring the retinal microvasculature at high altitude provides a surrogate for cerebral microvasculature, offering potential insight into cerebral hypoxia in critical illness. Additionally, while sex-specific differences in cardiovascular diseases are strongly supported, few have focused on differences in ocular blood flow. We evaluated the retinal microvasculature in males (n=11) and females (n=7) using functional optical coherence tomography at baseline (1,130m) (Day 0), following rapid ascent (Day 2) and prolonged exposure (Day 9) to high altitude (3,800m). Retinal vascular perfusion density (rVPD; an index of total blood supply), retinal thickness (RT; reflecting vascular and neural tissue volume) and arterial blood were acquired. As a group, rVPD increased on Day 2 vs. Day 0 (p<0.001) and was inversely related to PaO2 (R2=0.45; p=0.006). By Day 9, rVPD recovered to baseline, but was significantly lower in males vs. females (p=0.007). RT was not different on Day 2 vs. Day 0 (p>0.99) but was reduced by Day 9 relative to Day 0 and Day 2 (p<0.001). RT changes relative to Day 0 were inversely related to changes in PaO2 on Day 2 (R2=0.6; p=0.001) and Day 9 (R2=0.4; p=0.02). RT did not differ between sexes. These data suggest differential time course and regulation of the retina during rapid ascent and prolonged exposure to high altitude and are the first to demonstrate sex-specific differences in rVPD at high altitude. The ability to assess intact microvasculature contiguous with the brain has widespread research and clinical applications.
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Affiliation(s)
- Jacquie Baker
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Mohammad Amin Safarzadeh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Anthony V Incognito
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Nicholas G Jendzjowsky
- Division of Respiratory and Critical Care Physiology and Medicine, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States
| | - Glen Edward Foster
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Jordan D Bird
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Satish R Raj
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Caroline A Rickards
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Natalia Zubieta-DeUrioste
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,High Altitude Pulmonary and Pathology Institute (HAPPI - IPPA), La Paz, Bolivia
| | - Usman Alim
- Department of Computer Science, University of Calgary, Calgary, Alberta, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
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10
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Pollock SC. PEG-LEG ARTERIOLES: AN ADAPTATION TO CHRONIC RETINAL HYPOPERFUSION. Retin Cases Brief Rep 2022; 16:368-371. [PMID: 32044805 PMCID: PMC9022687 DOI: 10.1097/icb.0000000000000985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To describe a heretofore unreported retinal vascular sign related to chronic retinal hypoperfusion. METHODS A case report of a 42-year-old woman who was found to have a novel pattern of retinal vascular remodeling in the setting of severe bilateral occlusive disease of the carotid and vertebral arteries. RESULTS The patient had a childhood history of nasopharyngeal carcinoma, treated with external beam radiation. At age 35, she suffered bilateral occipital infarctions. A cerebral angiogram showed complete occlusion of both common carotid arteries and complete occlusion of the proximal segments of both vertebral arteries. Seven years after her stroke, examination of her fundus revealed a remarkable pattern of vascular remodeling that involved nearly all of the major retinal arterioles in both eyes. In each vessel, a narrowed proximal segment abruptly dilated to a larger-than-normal caliber at a distance of 1 to 2 disk diameters from the optic disk. The abnormally increased caliber extended into the retinal periphery. CONCLUSION Chronic severe retinal hypoperfusion due to profound carotid occlusive disease can lead to adaptive remodeling of the retinal vasculature in a pattern that closely resembles the iconic image of a pirate's peg leg.
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Affiliation(s)
- Stephen C Pollock
- Department of Ophthalmology, Duke University, Durham, North Carolina
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11
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Sousa DC, Leal I, Abegão Pinto L, Marques-Neves C. Comment on: Optical Coherence Tomography Angiography Features in Post-COVID-19 Pneumonia Patients: A Pilot Study. Am J Ophthalmol 2022; 234:330-331. [PMID: 34634236 PMCID: PMC8498777 DOI: 10.1016/j.ajo.2021.08.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 08/09/2021] [Indexed: 11/17/2022]
Affiliation(s)
- David Cordeiro Sousa
- Vision Sciences Study Center, Faculdade de Medicina, Universidade de Lisboa, 1649-035, Lisboa, Portugal; Vitreoretinal Unit, Royal Victorian Eye and Ear Hospital VIC 3002 East Melbourne, Melbourne, Australia.
| | - Inês Leal
- Vision Sciences Study Center, Faculdade de Medicina, Universidade de Lisboa, 1649-035, Lisboa, Portugal; Ophthalmology Department, Centro Hospitalar Universitário Lisboa Norte, 1649-038, Lisboa, Portugal
| | - Luís Abegão Pinto
- Vision Sciences Study Center, Faculdade de Medicina, Universidade de Lisboa, 1649-035, Lisboa, Portugal; Ophthalmology Department, Centro Hospitalar Universitário Lisboa Norte, 1649-038, Lisboa, Portugal
| | - Carlos Marques-Neves
- Vision Sciences Study Center, Faculdade de Medicina, Universidade de Lisboa, 1649-035, Lisboa, Portugal; Ophthalmology Department, Centro Hospitalar Universitário Lisboa Norte, 1649-038, Lisboa, Portugal
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12
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Blanco-Hernández DMR, Somilleda-Ventura SA, Chávez-Herrera R, Colas-Calvere MG, Lima-Gómez V. Compensatory contribution of retinal larger vessels to perfusion density in diabetics without retinopathy. Sci Rep 2022; 12:329. [PMID: 35013324 PMCID: PMC8748763 DOI: 10.1038/s41598-021-02554-y] [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: 06/14/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
Vessel and perfusion densities may decrease before diabetic retinopathy appears; it is unknown whether these changes affect the contribution of vessel density to perfusion density. This was a non-experimental, comparative, prospective, cross-sectional study in non-diabetic subjects (group 1) and diabetics without retinopathy (group 2). Vessel and perfusion densities in the superficial capillary plexus were compared between groups at the center, inner, and full regions and by field (superior, temporal, inferior, nasal) using optical coherence tomography angiography. Coefficients of determination (R2) between vessel and perfusion densities were calculated to find the contribution of larger retinal vessels to perfusion density. Percent differences were used to evaluate the contribution of these vessels to perfusion density in a regression model. There were 62 participants, 31 eyes by group; vessel and perfusion densities as well as the coefficients of determination between them were lower in group 2, especially in the nasal field (R2 0.85 vs. 0.71), which showed a higher contribution of larger retinal vessels to perfusion density. The regression model adjusted to a quadratic equation. In diabetics without retinopathy the contribution of vessel density to perfusion density may decrease; a low vessel density may increase the contribution of larger retinal vessels to perfusion density.
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Affiliation(s)
| | | | - Rebeca Chávez-Herrera
- Medicine School, Universidad Autonoma de Ciudad Juarez, 32315, Ciudad Juarez, Mexico
| | | | - Virgilio Lima-Gómez
- Ophthalmology Service, Hospital Juarez de Mexico, 07760, Mexico City, Mexico.
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13
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Gündoğan M, Vural E, Bayram N, Altunel O, Gündoğan F, Göktaş S. Change in retinal vessel diameter and choroidal thickness in patients with severe COVID-19: Change In Retinal Parameters In Patients With Severe COVID-19. Photodiagnosis Photodyn Ther 2021; 37:102674. [PMID: 34879296 PMCID: PMC8645280 DOI: 10.1016/j.pdpdt.2021.102674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 11/10/2021] [Accepted: 12/03/2021] [Indexed: 12/22/2022]
Abstract
Purpose : To compare the differences in retinal vascular structure and choroidal thickness between the active disease and post-recovery periods in COVID-19 patients and healthy controls. Material and Methods : This prospective, cross-sectional study included 30 eyes from 30 patients with severe COVID-19 and 30 eyes of 30 sex-matched healthy controls. Central macular thickness (CMT), subfoveal choroidal thickness (CT) and retinal vascular changes of patients were measured after positive polymerase chain reaction (PCR) (where the patient had COVID-19-related symptoms) and then three months after two negative PCRs. Laboratory parameters, including C-reactive protein and d-dimer levels, were also recorded. Results : The mean age of the patients was 47.90 ± 9.06 years in patients group, 49.07 ± 8.41 years in control goups (p = 0.467). In terms of choroidal thicknesses subfoveal, nasal and temporal region were significantly higher in the active disease period than control group (p = 0.019, p = 0.036, p = 0.003, respectively). When the after recovery period was compared with the control group in terms of choroidal thickness, although the choroidal thickness was higher in all regions, this difference was not found statistically significant. There was no statistically significant difference in CMT between groups (p = 0.506).The mean venous and arterial wall thicknesses were significantly higher in the active period than after recovery (p = 0.023, p = 0.013, respectively) but there were no differences between after recovery and control groups in the pairwise comparison (p = 0.851, p = 0.715, respectively). Conclusion : In patients with severe COVID-19, there are changes in thickness of the choroid and retinal vessel walls. While vascular wall thickness increases due to inflammation, the absence of lumen changes may be associated with hemodynamic variables.
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Affiliation(s)
- Medine Gündoğan
- Kayseri City Hospital, Department of Ophthalmology, Kayseri, Turkey.
| | - Esra Vural
- Kayseri City Hospital, Department of Ophthalmology, Kayseri, Turkey
| | - Nurettin Bayram
- Kayseri City Hospital, Department of Ophthalmology, Kayseri, Turkey
| | - Orhan Altunel
- Kutahya Health Sciences University, Evliya Celebi Education and Research Hospital, Department of Ophthalmology, Kutahya, Turkey
| | - Fatih Gündoğan
- Kayseri City Hospital, Department of Otolaryngology, Kayseri, Turkey
| | - Sertan Göktaş
- Kayseri City Hospital, Department of Ophthalmology, Kayseri, Turkey
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14
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Retinal Vascular Response to Hyperoxia in Patients with Diabetes Mellitus without Diabetic Retinopathy. J Ophthalmol 2021; 2021:9877205. [PMID: 34691774 PMCID: PMC8536458 DOI: 10.1155/2021/9877205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/27/2021] [Accepted: 10/07/2021] [Indexed: 12/13/2022] Open
Abstract
Purpose To evaluate the retinal vascular response to hyperoxia in patients with diabetes at the preclinical stage of diabetic retinopathy (DR) and to quantify the changes in comparison with normal subjects using optical coherence tomography angiography (OCTA). Methods In this prospective study, 40 eyes of 20 participants comprising 10 diabetic patients with no diabetic retinopathy (NDR) and 10 normal subjects were recruited. OCTA images were acquired in the resting position and were repeated after a hyperoxic challenge using a nasal mask connected to a reservoir bag supplying 100% oxygen at the rate of 15 L per minute for 5 minutes. The changes of mean parafoveal vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), the foveal avascular zone (FAZ) size, and the outer retina flow index were compared between two conditions in each group and between the two study groups. The statistical significance of differences in the means was evaluated using Student's t-test for unpaired samples with consideration of the generalized estimating equations (GEE) for intereye correlation. Results At baseline, the mean parafoveal VD of SCP and DCP were significantly lower in the NDR participants compared to the healthy subjects (P < 0.001 and P = 0.006, respectively). After induction of the hyperoxic challenge in healthy participants, mean parafoveal VD reduced at both the SCP and DCP, but reached a statistical significance only in DCP (P = 0.006). However, following induction of hyperoxic challenge in patients with NDR, no significant decline was noticed in mean parafoveal VD of SCP and DCP. The degree of change in mean parafoveal VD of DCP was statistically significantly more pronounced in healthy subjects compared to the NDR group (P = 0.034). The change in FAZ size and the outer retina flow index were comparable between the two study groups. Conclusion Retinal capillary layers responded differently to hyperoxia-induced challenge, and in normal subjects, the autoregulatory mechanism was mostly effective in the parafoveal DCP. Retinal vascular reactivity was impaired in SCP and DCP at the preclinical stage of DR. OCTA as a noninvasive modality was able to quantify the retinal vascular response to the hyperoxic challenge.
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15
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Auvazian SL, Cano J, Leahy S, Karamian P, Kashani A, Moshfeghi A, Ameri H, Blair NP, Shahidi M. Relating Retinal Vascular Oxygen Saturation and Microvasculature Morphology at Progressive Stages of Diabetic Retinopathy. Transl Vis Sci Technol 2021; 10:4. [PMID: 34111249 PMCID: PMC8107511 DOI: 10.1167/tvst.10.6.4] [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] [Indexed: 11/26/2022] Open
Abstract
Purpose Diabetic retinopathy (DR) is a common cause of vision loss in working age adults and presents changes in retinal vessel oxygenation and morphology. The purpose of this study was to test the hypothesis that there is an association of retinal vessel oxygen saturation with vessel density (VD) and tortuosity in DR. Methods Ninety-five subjects were classified in the following groups: nondiabetic control (N = 25), no DR (N = 28), mild nonproliferative DR (NPDR; N = 21), moderate to severe NPDR (N = 14), or treated proliferative DR (PDR; N = 7). Retinal oximetry was performed to measure arterial and venous oxygen saturation (SO2A and SO2V) and calculate oxygen extraction fraction (OEF). Optical coherence tomography angiography (OCTA) was performed for measurements of VD and vessel tortuosity index (VTI). Results There were statistically significant differences in SO2A and SO2V among groups (P< 0.004). SO2A and SO2V were higher in the PDR group compared to the control group and SO2V was also higher in the moderate to severe NPDR group. VD differed significantly among groups (P = 0.003), whereas VTI was not significantly different (P = 0.22). Compared to the control group, VD was lower in moderate to severe NPDR and PDR groups. VD was also lower in the PDR group than that in the no DR group (P = 0.03). There was a significant correlation of VTI with SO2V (r = 0.32, P = 0.002) and OEF (r = −0.35, P = 0.001). Conclusions Retinal vessel morphology, oxygenation, and tissue oxygen extraction were associated with each other in a cohort of subjects with and without DR. Translational Relevance The findings of this study have the potential to improve clinical management of DR by providing better understanding of human disease pathophysiology and propelling future studies to identify multiple image-based biomarkers for improved disease diagnosis and monitoring.
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Affiliation(s)
- Selin L Auvazian
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Jennifer Cano
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Sophie Leahy
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Preny Karamian
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Amir Kashani
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Andrew Moshfeghi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Hossein Ameri
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
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16
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Hua D, Xu Y, Heiduschka P, Zhang W, Zhang X, Zeng X, Zhu X, He T, Zheng H, Xiao X, Xing Y, Chen Z, Chen C. Retina Vascular Perfusion Dynamics During Exercise With and Without Face Masks in Healthy Young Adults: An OCT Angiography Study. Transl Vis Sci Technol 2021; 10:23. [PMID: 34003956 PMCID: PMC7991972 DOI: 10.1167/tvst.10.3.23] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose To determine possible impacts on retinal microvasculature in healthy young adults during exercise with a face mask, using optical coherence tomography angiography (OCTA). Methods Twenty-three healthy participants (23 eyes, 17 women and 6 men) performed the incremental continuous running test (ICRT) with different masks. OCTA of the macula and optic nerve head were performed before and after ICRT to detect changes in retinal vessel density (VD). All participants were in groups A, B, and C (before ICRT) and groups A′, B′, and C′ (after ICRT), which comprised data from volunteers without a mask, with a surgical mask, and with an N95 mask, respectively. Results Before ICRT, group C showed significantly reduced VD in the superficial plexus (SP), except foveal VD, compared with group A (P < 0.05). After ICRT, groups B′ and C′ showed significantly shorter maximum running time, lower oxygen saturation, and lower perifoveal VD of SP compared with group A′ (P < 0.05). Conclusions Use of an N95 mask reduced VD in SP even under quiescent conditions, which might have clinical implications for protecting healthy workers and indoor manual labor workers from potential risks of retinal damage due to long-term mask use. Moreover, mask use while exercising might lead to attenuated exercise ability and lower VD in SP, which should be investigated in additional studies. Translational Relevance Retina vascular perfusion dynamics could be monitored in vivo by OCTA, which would be valuable to study physiologic retinal blood flow redistribution and potential impacts on retinal vascular perfusion during exercise with face masks.
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Affiliation(s)
- Dihao Hua
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China.,Department of Ophthalmology, University of Muenster Medical Center, Muenster, Germany
| | - Yishuang Xu
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China.,Department of Ophthalmology, University of Muenster Medical Center, Muenster, Germany
| | - Peter Heiduschka
- Department of Ophthalmology, University of Muenster Medical Center, Muenster, Germany
| | - Wenliang Zhang
- Department of Ophthalmology, University of Muenster Medical Center, Muenster, Germany
| | - Xiao Zhang
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
| | | | - Xiangxiang Zhu
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
| | - Tao He
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
| | - Hongmei Zheng
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xuan Xiao
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yiqiao Xing
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China.,Wuhan Optometry Eye Hospital, Wuhan, China
| | - Zhen Chen
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
| | - Changzheng Chen
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, China
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17
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Abbinante G, Plaitano C, Gallo FG, Magli A. A case of retinal vascular involvement in a 6-year-old patient with Covid-19. Eur J Ophthalmol 2021; 32:NP1-NP5. [PMID: 34176314 PMCID: PMC9294615 DOI: 10.1177/11206721211027069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Purpose: This study evaluated fundus changes in a 6-year-old child who contracted
Sars-CoV-2 without developing symptoms of the disease. Materials and methods: The patient underwent a complete ophthalmic evaluation, which included
assessment of visual acuity with and without correction, extensive
ophthalmological examination, cicloplegic refraction by retinoscopy and
funduscopic examination, OCT, and angio-OCT examination. Results: Fundoscopic examination in a young patient with previous Sars-CoV-2 infection
showed marked vascular tortuosity, evident both at the posterior pole and
retinal periphery, especially on the arterial vasculature, and cotton wool
spots along the retinal vessels, highlightable also at OCT and angio-OCT
examination. These alterations persist at a 6-month follow-up. Conclusions: In COVID-19 infection, even in asymptomatic pediatric patients, vasculitis
develops also affecting the retinal vessels, appreciable on fundus
examination. A thorough eye examination in all COVID-19 patients with close
follow-up is therefore important. This is the first case report on retinal
changes in a pediatric patient.
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Affiliation(s)
- Giulia Abbinante
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Carmen Plaitano
- Department of Ophthalmology, A.O.U. San Giovanni Di Dio e Ruggi d'Aragona - Scuola Medica Salernitana, Salerno, Italy
| | | | - Adriano Magli
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
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18
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Sousa DC, Leal I, Moreira S, do Vale S, Silva-Herdade AS, Aguiar P, Dionísio P, Abegão Pinto L, Castanho MARB, Marques-Neves C. Retinal Vascular Reactivity in Type 1 Diabetes Patients Without Retinopathy Using Optical Coherence Tomography Angiography. Invest Ophthalmol Vis Sci 2021; 61:49. [PMID: 32574352 PMCID: PMC7415313 DOI: 10.1167/iovs.61.6.49] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose We hypothesize that patients with type 1 diabetes (T1D) may have abnormal retinal vascular responses before diabetic retinopathy (DR) is clinically evident. Optical coherence tomography angiography (OCTA) was used to dynamically assess the retinal microvasculature of diabetic patients with no clinically visible retinopathy. Methods Controlled nonrandomized interventional study. The studied population included 48 eyes of 24 T1D patients and 24 demographically similar healthy volunteers. A commercial OCTA device (AngioVue) was used, and two tests were applied: (1) the hypoxia challenge test (HCT) and (2) the handgrip test to induce a vasodilatory or vasoconstrictive response, respectively. The HCT is a standardized test that creates a mild hypoxic environment equivalent to a flight cabin. The handgrip test (i.e., isometric exercise) induces a sympathetic autonomic response. Changes in the parafoveal superficial and deep capillary plexuses in both tests were compared in each group. Systemic cardiovascular responses were also comparatively evaluated. Results In the control cohort, the vessel density of the median parafoveal superficial and deep plexuses increased during hypoxia (F1,23 = 15.69, P < 0.001 and F1,23 = 16.26, P < 0.001, respectively). In the T1D group, this physiological response was not observed in either the superficial or the deep retinal plexuses. Isometric exercise elicited a significant decrease in vessel density in both superficial and deep plexuses in the control group (F1,23 = 27.37, P < 0.0001 and F1,23 = 27.90, P < 0.0001, respectively). In the T1D group, this response was noted only in the deep plexus (F1,23 = 11.04, P < 0.01). Conclusions Our work suggests there is an early impairment of the physiological retinal vascular response in patients with T1D without clinical diabetic retinopathy.
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19
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Karapapak M, Güven D, Demir M, Tiryaki Demir S, Uslu Dogan C. Optical coherence tomography angiography of central serous chorioretinopathy patients' response to breath-holding manoeuvre. Acta Ophthalmol 2020; 98:787-794. [PMID: 32996704 DOI: 10.1111/aos.14625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/28/2020] [Accepted: 08/28/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE To demonstrate through the use of optical coherence tomography angiography (OCTA) that normal vasoreactivity cannot be monitored in central serous chorioretinopathy (CSR) patients in the presence of vasoactive stimuli owing to hypoxia caused by the breath-holding manoeuvre (BHM). METHODS This cross-sectional study included a total of 210 eyes, including 70 CSR patients (70 symptomatic eyes, 70 asymptomatic eyes) and 70 control group. Images of the macula (3 × 3 mm) and the optic disc (4.5 × 4.5 mm) were obtained at the baseline and after BHM using OCTA. The change in vascular parameters in the OCTA after BHM was evaluated in CSR patients and the control group. RESULTS In the symptomatic eyes of CSR patients, the mean whole image vessel density (VD) in the superficial capillary plexus decreased from 48.0 ± 3.5% under baseline conditions to 46.0 ± 4.5% after BHM (p < 0.01), and the mean whole VD in the deep capillary plexus decreased from 47.9 ± 8.0% under baseline conditions to 46.9 ± 6.7% after BHM (p < 0.01). The OCTA after BHM revealed a decrease in the mean whole image VD of the optic disc in both symptomatic (50.4 ± 2.1% to 49.6 ± 2.0%, p < 0.05) and asymptomatic (50.9 ± 1.8% to 50.4 ± 1.9%, p < 0.05) eyes of CSR patients. No difference for any mean VD of the control group was seen between the baseline and after BHM. Outer retinal flow areas increased significantly after BHM compared with the baseline in both eyes of CSR patients. CONCLUSION These results suggest that CSR pathogenesis is related to an imbalance in local vascular regulation and the sympathetic activity of the autonomic nervous system. This technique constitutes a new way of studying retinal vascular changes and may be applied to CSR patients.
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Affiliation(s)
- Murat Karapapak
- Department of Ophthalmology Basaksehir Cam and Sakura City Hospital Istanbul Turkey
| | - Dilek Güven
- Department of Ophthalmology Sisli Hamidiye Etfal Training and Research Hospital University of Health Sciences Istanbul Turkey
| | - Mehmet Demir
- Department of Ophthalmology Sisli Hamidiye Etfal Training and Research Hospital University of Health Sciences Istanbul Turkey
| | - Semra Tiryaki Demir
- Department of Ophthalmology Sisli Hamidiye Etfal Training and Research Hospital University of Health Sciences Istanbul Turkey
| | - Ceylan Uslu Dogan
- Department of Ophthalmology Sisli Hamidiye Etfal Training and Research Hospital University of Health Sciences Istanbul Turkey
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Longitudinal stability of retinal blood flow regulation in response to flicker stimulation and systemic hyperoxia in mice assessed with laser speckle flowgraphy. Sci Rep 2020; 10:19796. [PMID: 33188259 PMCID: PMC7666208 DOI: 10.1038/s41598-020-75296-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/08/2020] [Indexed: 11/08/2022] Open
Abstract
This study aimed to evaluate longitudinal changes in retinal blood flow in response to flicker stimulation and systemic hyperoxia in mice using a laser speckle flowgraphy (LSFG-Micro). The retinal blood flow in vascular area surrounding the optic nerve head was measured in 8-week-old male mice every 2 weeks until age 20-week. The coefficient of variation of retinal blood flow under resting condition was analyzed every 2 weeks to validate the consistency of the measurement. On day 1 of the experiment, retinal blood flow was assessed every 20 s for 6 min during and after 3 min flicker light (12 Hz) stimulation; on day 2, retinal blood flow was measured every minute for 20 min during and after 10 min systemic hyperoxia; and on day 3, electroretinography (ERG) was performed. Body weight, systemic blood pressure, and ocular perfusion pressure increased significantly with age, but the resting retinal blood flow and ERG parameters remained unchanged. Retinal blood flow significantly increased with flicker stimulation and decreased with systemic hyperoxia, independent of age. The LSFG-Micro provides consistent and reproducible retinal blood flow measurement in adult mice. Longitudinal assessments of retinal blood flow in response to flicker stimulation and systemic hyperoxia may be useful indexes for noninvasive monitoring of vascular function in retinas.
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Invernizzi A, Torre A, Parrulli S, Zicarelli F, Schiuma M, Colombo V, Giacomelli A, Cigada M, Milazzo L, Ridolfo A, Faggion I, Cordier L, Oldani M, Marini S, Villa P, Rizzardini G, Galli M, Antinori S, Staurenghi G, Meroni L. Retinal findings in patients with COVID-19: Results from the SERPICO-19 study. EClinicalMedicine 2020; 27:100550. [PMID: 32984785 PMCID: PMC7502280 DOI: 10.1016/j.eclinm.2020.100550] [Citation(s) in RCA: 166] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/29/2020] [Accepted: 09/03/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Coronavirus disease 2019 (COVID-19) has been associated to microvascular alterations. We screened the fundus of patients with COVID-19 to detect alterations of the retina and its vasculature and to assess possible correlations with clinical parameters. METHODS Cross-sectional study. The presence of retinal alterations in patients with COVID-19 and subjects unexposed to the virus was assessed using fundus photographs and their prevalence was compared. Mean arteries diameter (MAD) and mean veins diameter (MVD) were compared between patients and unexposed subjects with multiple linear regression including age, sex, ethnicity, body mass index, smoking/alcohol consumption, hypertension, hyperlipidaemia, diabetes as covariates. The influence of clinical/lab parameters on retinal findings was tested in COVID-19 patients. FINDINGS 54 patients and 133 unexposed subjects were enrolled. Retinal findings in COVID-19 included: haemorrhages (9·25%), cotton wools spots (7·4%), dilated veins (27·7%), tortuous vessels (12·9%). Both MAD and MVD were higher in COVID-19 patients compared to unexposed subjects (98·3 ± 15·3 µm vs 91·9 ± 11·7 µm, p = 0.006 and 138·5 ± 21·5 µm vs 123·2 ± 13·0 µm, p<0.0001, respectively). In multiple regression accounting for covariates MVD was positively associated with COVID-19 both in severe (coefficient 30·3, CI95% 18·1-42·4) and non-severe (coefficient 10·3, CI95% 1·6-19·0) cases compared to unexposed subjects. In COVID-19 patients MVD was negatively correlated with the time from symptoms onset (coefficient -1·0, CI 95% -1·89 to -0·20) and positively correlated with disease severity (coefficient 22·0, CI 95% 5·2-38·9). INTERPRETATION COVID-19 can affect the retina. Retinal veins diameter seems directly correlated with the disease severity. Its assessment could have possible applications in the management of COVID-19. FUNDING None.
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Affiliation(s)
- Alessandro Invernizzi
- Eye Clinic, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
- The Discipline of Clinical Ophthalmology and Eye Health, Save Sight Institute, Sydney Eye Hospital, Faculty of Medicine and Health, The University of Sydney, 8 Macquarie Street, Sydney, NSW 2001, Australia
- Corresponding author at: Eye Clinic, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy.
| | - Alessandro Torre
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Salvatore Parrulli
- Eye Clinic, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | - Federico Zicarelli
- Eye Clinic, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | - Marco Schiuma
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Valeria Colombo
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Andrea Giacomelli
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Mario Cigada
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | - Laura Milazzo
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Annalisa Ridolfo
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Ivano Faggion
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Laura Cordier
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Marta Oldani
- Eye Clinic, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Sara Marini
- Eye Clinic, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Paolo Villa
- Emergency Unit, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Giuliano Rizzardini
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Massimo Galli
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Spinello Antinori
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Giovanni Staurenghi
- Eye Clinic, Luigi Sacco Hospital, ASST Fatebenefratelli-Sacco, Milan, Italy
- Department of Biomedical and Clinical Sciences “L. Sacco”, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | - Luca Meroni
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Milan, Italy
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Li C, Zhong P, Yuan H, Dong X, Peng Q, Huang M, Wu Q, Liu B, Xu M, Kuang Y, Zeng X, Xiao Y, Fang Y, Yu H, Yang X. Retinal microvasculature impairment in patients with congenital heart disease investigated by optical coherence tomography angiography. Clin Exp Ophthalmol 2020; 48:1219-1228. [PMID: 32860305 PMCID: PMC7756805 DOI: 10.1111/ceo.13846] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/12/2020] [Accepted: 08/18/2020] [Indexed: 12/11/2022]
Abstract
Importance A high prevalence of retinal abnormalities have been reported in congenital heart disease (CHD), but quantitative analysis of retinal vasculature is scarce. Optical coherence tomography angiography (OCTA) is a noninvasive method to quantitatively assess the retinal microvasculature. Background To investigate the retinal microvasculature changes in CHD patients by using OCTA. Design Cross‐sectional study. Participants A total of 158 participants including 57 cyanotic CHD (CCHD) patients, 60 acyanotic CHD (ACHD) patients and 41 control subjects were included. Methods All participants underwent a comprehensive ophthalmologic examination, including refraction measurement, intraocular pressure measurement and OCTA. Main Outcome Measures Vessel density (VD) was measured within the radial peripapillary capillary (RPC), superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the macula. Results CCHD patients had significantly lower VD in the RPC, SCP and DCP (all P < .01) compared to control subjects, and significantly lower VD in the RPC and DCP (both P < .05) compared to ACHD patients. Besides, among the CHD group, VD in the RPC was positively correlated with oxygen saturation (whole image, ρ = 0.45; peripapillary, ρ = 0.48) and negatively correlated with haematocrit (whole image, ρ = 0.55; peripapillary, ρ = 0.55) (all P < .001). Conclusions and Relevance Retinal VD might be a surrogate to reflect the effect of chronic systemic hypoxemia in CHD patients. OCTA could be a convenient and noninvasive tool to evaluate the retinal structure and function in CHD patients.
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Affiliation(s)
- Cong Li
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
| | - Pingting Zhong
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China.,Medical College, Shantou University, Shantou, China
| | - Haiyun Yuan
- Department of Cardiovascular Surgery, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xinran Dong
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
| | - Qingsheng Peng
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China.,Medical College, Shantou University, Shantou, China
| | - Manqing Huang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
| | - Qiaowei Wu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Baoyi Liu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Minghui Xu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
| | - Yu Kuang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
| | - Xiaomin Zeng
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Yu Xiao
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Ying Fang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
| | - Honghua Yu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
| | - Xiaohong Yang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, China
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23
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Gerhard G, Chua J, Tan B, Wong D, Schmidl D, Schmetterer L. Retinal Neurovascular Coupling in Diabetes. J Clin Med 2020; 9:jcm9092829. [PMID: 32882896 PMCID: PMC7565465 DOI: 10.3390/jcm9092829] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 12/15/2022] Open
Abstract
Neurovascular coupling, also termed functional hyperemia, is one of the physiological key mechanisms to adjust blood flow in a neural tissue in response to functional activity. In the retina, increased neural activity, such as that induced by visual stimulation, leads to the dilatation of retinal arterioles, which is accompanied by an immediate increase in retinal and optic nerve head blood flow. According to the current scientific view, functional hyperemia ensures the adequate supply of nutrients and metabolites in response to the increased metabolic demand of the neural tissue. Although the molecular mechanisms behind neurovascular coupling are not yet fully elucidated, there is compelling evidence that this regulation is impaired in a wide variety of neurodegenerative and vascular diseases. In particular, it has been shown that the breakdown of the functional hyperemic response is an early event in patients with diabetes. There is compelling evidence that alterations in neurovascular coupling precede visible signs of diabetic retinopathy. Based on these observations, it has been hypothesized that a breakdown of functional hyperemia may contribute to the retinal complications of diabetes such as diabetic retinopathy or macular edema. The present review summarizes the current evidence of impaired neurovascular coupling in patients with diabetes. In this context, the molecular mechanisms of functional hyperemia in health and disease will be covered. Finally, we will also discuss how neurovascular coupling may in future be used to monitor disease progression or risk stratification.
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Affiliation(s)
- Garhöfer Gerhard
- Department of Clinical Pharmacology, Medical University Vienna, 1090 Vienna, Austria; (G.G.); (D.S.)
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
| | - Damon Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University Vienna, 1090 Vienna, Austria; (G.G.); (D.S.)
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University Vienna, 1090 Vienna, Austria; (G.G.); (D.S.)
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (J.C.); (B.T.); (D.W.)
- Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore 639798, Singapore
- Institute for Health Technologies, Nanyang Technological University, Singapore 308232, Singapore
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, 1090 Vienna, Austria
- Institute of Molecular and Clinical Ophthalmology, CH-4031 Basel, Switzerland
- Correspondence: ; Tel.: +43-1-40400-29810
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24
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Sousa DC, Leal I, Moreira S, do Vale S, Silva-Herdade AS, Aguiar P, Dionísio P, Abegão Pinto L, Castanho MARB, Marques-Neves C. A Protocol to Evaluate Retinal Vascular Response Using Optical Coherence Tomography Angiography. Front Neurosci 2019; 13:566. [PMID: 31249500 PMCID: PMC6582622 DOI: 10.3389/fnins.2019.00566] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/17/2019] [Indexed: 12/26/2022] Open
Abstract
Introduction Optical coherence tomography angiography (OCT-A) is a novel diagnostic tool with increasing applications in ophthalmology clinics that provides non-invasive high-resolution imaging of the retinal microvasculature. Our aim is to report in detail an experimental protocol for analyzing both vasodilatory and vasoconstriction retinal vascular responses with the available OCT-A technology. Methods A commercial OCT-A device was used (AngioVue®, Optovue, CA, United States), and all examinations were performed by an experienced technician using the standard protocol for macular examination. Two standardized tests were applied: (i) the hypoxia challenge test (HCT) and (ii) the handgrip test, in order to induce a vasodilatory and vasoconstriction response, respectively. OCT-A was performed at baseline conditions and during the stress test. Macular parafoveal vessel density of the superficial and deep plexuses was assessed from the en face angiograms. Statistical analysis was performed using STATA v14.1 and p < 0.05 was considered for statistical significance. Results Twenty-four eyes of 24 healthy subjects (10 male) were studied. Mean age was 31.8 ± 8.2 years (range, 18–57 years). Mean parafoveal vessel density in the superficial plexus increased from 54.7 ± 2.6 in baseline conditions to 56.0 ± 2.0 in hypoxia (p < 0.01). Mean parafoveal vessel density in the deep plexuses also increased, from 60.4 ± 2.2 at baseline to 61.5 ± 2.1 during hypoxia (p < 0.01). The OCT-A during the handgrip test revealed a decrease in vessel density in both superficial (55.5 ± 2.6 to 53.7 ± 2.9, p < 0.001) and deep (60.2 ± 1.8 to 56.7 ± 2.8, p < 0.001) parafoveal plexuses. Discussion In this work, we detail a simple, non-invasive, safe, and non-costly protocol to assess a central nervous system vascular response (i.e., the retinal circulation) using OCT-A technology. A vasodilatory response and a vasoconstriction response were observed in two physiologic conditions—mild hypoxia and isometric exercise, respectively. This protocol constitutes a new way of studying retinal vascular changes that may be applied in health and disease of multiple medical fields.
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Affiliation(s)
- David Cordeiro Sousa
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Manchester Royal Eye Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Inês Leal
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Susana Moreira
- Respiratory Medicine Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Sónia do Vale
- Endocrinology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Endocrinology Department, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ana S Silva-Herdade
- Instituto de Bioquímica, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Patrício Aguiar
- Medicine I Department, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Clinica Universitária de Medicina I, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Patrícia Dionísio
- Respiratory Medicine Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Luís Abegão Pinto
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel A R B Castanho
- Instituto de Bioquímica, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Carlos Marques-Neves
- Ophthalmology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Vision Sciences Study Center, CECV, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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25
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Yang Y, Yang D, Sun Y, Xie Y, Zhang Z, Li S, Wu S, Wang N. Retinal vessel oxygen saturation and vessel diameter in healthy individuals during high-altitude exposure. Acta Ophthalmol 2019; 97:279-286. [PMID: 30259682 DOI: 10.1111/aos.13897] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 07/20/2018] [Indexed: 12/29/2022]
Abstract
PURPOSE To assess changes of retinal vessel oxygen saturation and vessel diameter in healthy individuals during high-altitude exposure. METHODS Retinal oxygen saturation and vessel diameter were obtained at sea level (SL, 40 m) and high altitude (HA, 3681 m) on 17 healthy individuals from Beijing (six males, 28.06 ± 8.06 years) using Oxymap T1 and then compared with 21 residents from Yushu (10 males, 28.63 ± 6.00 years). Systemic and ocular parameters were also measured before and after high-altitude exposure. Data were presented as mean ± SD and analysed using paired and independent Student t-test with significance accepted at p < 0.05. RESULTS Short-term high-altitude exposure of Beijing Group significantly affected all the systemic and ocular parameters, as well as retinal oxygen saturation and vessel diameter ranging from overall quadrant to different quadrants, other than retinal venous oxygen saturation and retinal arterial diameter. However, these changes were not evident in those permanently living at HA. Pearson's correlation analysis revealed correlations between retinal oxygen saturation and systemic and ocular parameters (all p < 0.05). The multivariate linear regression analysis indicated that retinal arterial oxygen saturation was significantly associated with arterial peripheral arterial oxygen saturation (SpO2 ) and subfoveal choroidal thickness. CONCLUSION Short-term exposure to HA induces retinal microcirculation disturbance and auto-regulatory response in healthy individuals, which is probably attributed to arterial SpO2 and endothelial dysfunction under hypoxic conditions.
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Affiliation(s)
- Yiquan Yang
- Beijing Ophthalmology and Visual Sciences Key Laboratory Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing China
- Beijing Institute of Ophthalmology Beijing Tongren Hospital Capital Medical University Beijing China
| | - Diya Yang
- Beijing Ophthalmology and Visual Sciences Key Laboratory Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing China
| | - Yunxiao Sun
- Beijing Ophthalmology and Visual Sciences Key Laboratory Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing China
- Beijing Institute of Ophthalmology Beijing Tongren Hospital Capital Medical University Beijing China
| | - Yuan Xie
- Beijing Ophthalmology and Visual Sciences Key Laboratory Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing China
- Beijing Institute of Ophthalmology Beijing Tongren Hospital Capital Medical University Beijing China
| | - Zheng Zhang
- Beijing Ophthalmology and Visual Sciences Key Laboratory Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing China
| | - Shuning Li
- Beijing Ophthalmology and Visual Sciences Key Laboratory Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing China
| | - Shizheng Wu
- Departments of Neurology The Qinghai Provincial People's Hospital Xining Qinghai China
| | - Ningli Wang
- Beijing Ophthalmology and Visual Sciences Key Laboratory Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing China
- Beijing Institute of Ophthalmology Beijing Tongren Hospital Capital Medical University Beijing China
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Abstract
PURPOSE Continuous peripheral pulse oximetry for monitoring adequacy of oxygenation is probably the most important technological advance for patients' monitoring and safety in the last decades. Pulse oximetry has the disadvantage of measuring the peripheral circulation, and the only mean to measure oxygen content of the central circulation is by invasive technology. Determination of blood oxyhaemoglobin saturation in the retinal vessels of the eye can be achieved noninvasively through spectrophotometric retinal oximetry which provides access to the central nervous system circulation. The aim of the thesis was to determine whether retinal oximetry technique can be applied for estimation of the central nervous system circulation which until now has only been possible invasively. This was achieved by measuring oxyhaemoglobin saturation in three adult subject study groups: in people with central retinal vein occlusion (CRVO) to observe local tissue hypoxia, in patients with severe chronic obstructive pulmonary disease (COPD) on long-term oxygen therapy to observe systemic hypoxaemia and in healthy subjects during hyperoxic breathing to observe systemic hyperoxemia. In addition, the fourth study that is mentioned was performed to test whether retinal oximetry is feasible for neonates. METHODS Retinal oximetry in central retinal vein occlusion: Sixteen subjects with central retinal vein occlusion participated in the study. The oxyhaemoglobin saturation of the central retinal vein occlusion affected eye was compared with the fellow unaffected eye. Retinal oximetry in healthy people under hyperoxia: Thirty healthy subjects participated in the study, and the oxyhaemoglobin saturation of retinal arterioles and venules was compared between normoxic and hyperoxic breathing. Retinal oximetry in severe chronic obstructive pulmonary disease: Eleven patients with severe chronic obstructive pulmonary disease participated in the study. Retinal oximetry measurements were made with and without their daily supplemental oxygen therapy. Retinal arteriolar oxyhaemoglobin saturation when inspiring ambient air was compared with blood samples from the radial artery and finger pulse oximetry and healthy controls. The healthy control group was assembled from our database for comparison of oxyhaemoglobin saturation of retinal arterioles and venules during the ambient air breathing. The retinal oximeter is based on a conventional fundus camera and a specialized software. A beam splitter coupled with two high-resolution digital cameras allows for simultaneous acquisition of retinal images at separative wavelengths for calculation of oxyhaemoglobin saturation. In addition, retinal images of 28 full-term healthy neonates were obtained with scanning laser ophthalmoscope combined with modified Oxymap analysis software for calculation of the optical density ratio and vessel diameter RESULTS: Retinal oximetry in central retinal vein occlusion: Mean retinal venous oxyhaemoglobin saturation was 31 ± 12% in CRVO eyes and 52 ± 11% in unaffected fellow eyes (mean ± SD, n = 14, p < 0.0001). The arteriovenous oxygen difference (AV-difference) was 63 ± 11% in CRVO eyes and 43 ± 7% in fellow eyes (p < 0.0001). The variability of retinal venous oxyhaemoglobin saturation was considerable within and between eyes affected by CRVO. There was no difference in oxyhaemoglobin saturation of retinal arterioles between the CRVO eyes and the unaffected eyes (p = 0.49). Retinal oximetry in healthy people under hyperoxia: During hyperoxic breathing, the oxyhaemoglobin saturation in retinal arterioles increased to 94.5 ± 3.8% as compared with 92.0 ± 3.7% at baseline (n = 30, p < 0.0001). In venules, the mean oxyhaemoglobin saturation increased to 76.2 ± 8.0% from 51.3 ± 5.6% (p < 0.0001) at baseline. The AV-difference was markedly lower during hyperoxic breathing as compared with the normoxic breathing (18.3 ± 9.0% versus 40.7 ± 5.7%, p < 0.0001). Retinal oximetry in severe chronic obstructive pulmonary disease: During ambient air breathing, chronic obstructive pulmonary disease subjects had significantly lower oxyhaemoglobin saturation than healthy controls in both retinal arterioles (87.2 ± 4.9% versus 93.4 ± 4.3%, p = 0.02, n = 11) and venules (45.0 ± 10.3% versus 55.2 ± 5.5%, p = 0.01) but the AV-difference was not markedly different (p = 0.17). Administration of their prescribed oxygen therapy significantly increased the oxyhaemoglobin saturation in retinal arterioles (87.2 ± 4.9% to 89.5 ± 6.0%, p = 0.02) but not in venules (45.0 ± 10.3% to 46.7 ± 12.8%, p = 0.3). Retinal oximetry values were slightly lower than finger pulse oximetry (mean percentage points difference = -3.1 ± 5.5) and radial artery blood values (-5.0 ± 5.4). Retinal oximetry study in neonates: The modified version of the retinal oximetry instrument estimated the optical density ratio in retinal arterioles to be 0.256 ± 0.041 that was significantly different from the 0.421 ± 0.089 in venules (n = 28, p < 0.001, paired t-test). The vascular diameter of retinal arterioles was markedly narrower than of venules (14.1 ± 2.7 and 19.7 ± 3.7 pixels, p < 0.001). CONCLUSION The results of this thesis indicate that spectrophotometric retinal oximetry is sensitive to both local and systemic changes in oxyhaemoglobin saturation. Retinal oxyhaemoglobin saturation values are slightly lower than radial artery blood sample and finger pulse oximetry values. The discrepancies between the different modalities are expected to derive from countercurrent exchange between central retinal artery and vein within the optic nerve but calibration issues cannot be excluded as contributing to this difference. Despite these differences, the findings indicate the potential of retinal oximetry for noninvasive real-time measurements of oxyhaemoglobin saturation in central nervous system vessels. Following calibration upgrade and technological improvement, verification retinal oximetry may potentially be applied to critically ill and anaesthesia care patients. The study on combined scanning laser ophthalmoscope and retinal oximetry supports the feasibility of the technique for oximetry analysis in newly born babies.
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Wei X, Balne PK, Meissner KE, Barathi VA, Schmetterer L, Agrawal R. Assessment of flow dynamics in retinal and choroidal microcirculation. Surv Ophthalmol 2018; 63:646-664. [DOI: 10.1016/j.survophthal.2018.03.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 03/19/2018] [Accepted: 03/19/2018] [Indexed: 01/08/2023]
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Rose K, Krema H, Durairaj P, Dangboon W, Chavez Y, Kulasekara SI, Hudson C. Retinal perfusion changes in radiation retinopathy. Acta Ophthalmol 2018; 96:e727-e731. [PMID: 29998553 DOI: 10.1111/aos.13797] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/24/2018] [Indexed: 12/31/2022]
Abstract
PURPOSE To investigate retinal blood flow and oxygen saturation changes in patients diagnosed with retinopathy following plaque radiation treatment to treat choroidal melanoma. METHODS Eight patients (mean age 55.75 years, SD 12.58 years) who have developed unilateral ischaemic radiation-related retinopathy as confirmed by wide-field fluorescein angiography were recruited for the study. The fellow eye with no other ocular or retinal pathology was used as control. Both eyes underwent measurement of total retinal blood flow (TRBF) and retinal blood oxygen saturation using prototype methodologies of Doppler Spectral Domain Optical Coherence Tomography (OCT) and Hyperspectral Retinal Camera, respectively. RESULTS The average TRBF in the retinopathy eye was significantly lower compared to the fellow eye (33.48 ± 12.73 μl/min versus 50.37 ± 15.26 μl/min; p = 0.013). The arteriolar oxygen saturation (SaO2 ) and venular oxygen saturation (SvO2 ) were higher in the retinopathy eye compared to the fellow eye (101.11 ± 4.26%, versus 94.45 ± 5.79%; p = 0.008) and (62.96 ± 11.05% versus 51.24 ± 6.88%, p = 0.051), respectively. CONCLUSION The ionizing radiation seems to have an impact on the TRBF, SaO2 and SvO2 , clinically presenting similar to a rapidly developing diabetic retinopathy. The results show an altered retinal vascular physiology in patients with radiation-related retinopathy.
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Affiliation(s)
- Kalpana Rose
- School of Optometry and Vision Science; University of Waterloo; Waterloo Ontario Canada
- Department of Ophthalmology and Vision Sciences; Toronto Western Hospital; University of Toronto; Toronto Ontario Canada
| | - Hatem Krema
- Department of Ophthalmology and Vision Sciences; Toronto Western Hospital; University of Toronto; Toronto Ontario Canada
- Ocular Oncology Service; Princess Margaret Cancer Centre/University Health Network; Toronto Ontario Canada
| | - Priya Durairaj
- Ocular Oncology Service; Princess Margaret Cancer Centre/University Health Network; Toronto Ontario Canada
| | - Wantanee Dangboon
- Ocular Oncology Service; Princess Margaret Cancer Centre/University Health Network; Toronto Ontario Canada
| | - Yael Chavez
- Ocular Oncology Service; Princess Margaret Cancer Centre/University Health Network; Toronto Ontario Canada
| | - Susith I. Kulasekara
- Department of Ophthalmology; Royal Darwin Hospital; Darwin Northern Territory Australia
| | - Christopher Hudson
- School of Optometry and Vision Science; University of Waterloo; Waterloo Ontario Canada
- Department of Ophthalmology and Vision Sciences; Toronto Western Hospital; University of Toronto; Toronto Ontario Canada
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Sousa DC, Leal I, Moreira S, Dionísio P, Abegão Pinto L, Marques-Neves C. Hypoxia challenge test and retinal circulation changes - a study using ocular coherence tomography angiography. Acta Ophthalmol 2018; 96:e315-e319. [PMID: 29160042 DOI: 10.1111/aos.13622] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 09/12/2017] [Indexed: 12/17/2022]
Abstract
PURPOSE Previous studies report that the response of retinal vessels to a decrease in oxygen (hypoxia) is vasodilation, thus increasing blood flow. We aimed to characterize the changes in retinal microvasculature induced by a mild hypoxia stress test in a healthy population, using ocular coherence tomography angiography (OCT-A) technology. METHODS Interventional repeated-measures study. The standardized hypoxia challenge test (HCT) was performed to all volunteers, according to the British Thoracic Society protocol. Ocular coherence tomography angiography (OCT-A) was performed at three time-points (baseline, during HCT and 30' posthypoxia). Macular and peripapillary vessel densities were assessed using the built-in software. To minimize bias, analysis was performed separately in right (OD) and left (OS) eyes. Repeated-measures anova and mean comparison analysis were used as statistical tests (stata v13). RESULTS Studied population included 30 healthy subjects (14 women), with a mean age of 28.8 ± 4.2 [range 22-37] years. Baseline vessel density increased in hypoxic conditions and subsequently decreased to near-baseline values in posthypoxia conditions. This pattern was observed for both eyes in both parafovea (OD: 55.3 ± 2.3 to 56.7 ± 1.9 to 55.8 ± 1.9, p < 0.05; OS: 56.9 ± 2.1 to 57.9 ± 1.9 to 57.3 ± 1.7, p < 0.05) and peripapillary (OD: 60.5 ± 0.5 to 62.6 ± 0.5 to 60.1 ± 0.4, p < 0.05; OS: 60.4 ± 0.4 to 62.3 ± 0.5 to 60.7 ± 0.4, p < 0.05) areas. CONCLUSION To our knowledge, there are no published data specifically addressing mild hypoxia conditions and retinal microvasculature changes, using OCT-A. This pilot study may pave way to better understand vascular responses in disease setting.
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Affiliation(s)
- David Cordeiro Sousa
- Ophthalmology Department; Hospital de Santa Maria; Lisbon Portugal
- Vision Sciences Study Center; CECV, Faculdade de Medicina, Universidade de Lisboa; Lisbon Portugal
| | - Inês Leal
- Ophthalmology Department; Hospital de Santa Maria; Lisbon Portugal
- Vision Sciences Study Center; CECV, Faculdade de Medicina, Universidade de Lisboa; Lisbon Portugal
| | - Susana Moreira
- Pulmonology Department; Hospital de Santa Maria; Lisbon Portugal
- Innate Immunity and Inflammation Laboratory; Instituto Gulbenkian da Ciência; Oeiras Portugal
| | | | - Luís Abegão Pinto
- Ophthalmology Department; Hospital de Santa Maria; Lisbon Portugal
- Vision Sciences Study Center; CECV, Faculdade de Medicina, Universidade de Lisboa; Lisbon Portugal
| | - Carlos Marques-Neves
- Ophthalmology Department; Hospital de Santa Maria; Lisbon Portugal
- Vision Sciences Study Center; CECV, Faculdade de Medicina, Universidade de Lisboa; Lisbon Portugal
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Investigation of causes of sex-related differences in ocular blood flow in healthy eyes determined by laser speckle flowgraphy. Sci Rep 2017; 7:13878. [PMID: 29066801 PMCID: PMC5655330 DOI: 10.1038/s41598-017-14118-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/02/2017] [Indexed: 12/28/2022] Open
Abstract
Sex-related differences are present in the systemic and ocular blood flow. However, the cause of the sex-related differences has not been determined. We investigated the ocular blood flow, represented by the mean blur rate (MBR), on the optic nerve head (ONH) determined by laser speckle flowgraphy in 138 males (63.9 ± 8.9 years) and 194 females (63.5 ± 9.4 years). The correlations between the MBR on the ONH and the clinical data were determined. The overall ONH-MBR was significantly higher in females than males (P < 0.001). In addition, the levels of the hemoglobin and hematocrit were significantly lower in females than in males (P < 0.001). The ONH-MBR was negatively and significantly correlated with the levels of the hemoglobin and hematocrit (both, P < 0.001). Multiple regression analyses showed that the sex (β = 0.248, P < 0.001) was an independent factor correlated with the ONH-MBR when the clinical examination data were not included in the analyses. However, when the clinical examination data were included, the hemoglobin level (β = −0.295, P < 0.001) was an independent factor that contributed to the ONH-MBR but the sex was not. We conclude that the sex-related differences in the hemoglobin level and the negative correlation between hemoglobin and the ONH-MBR are the causes of the sex-related differences in the ONH-MBR.
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OCT Angiography Changes in the 3 Parafoveal Retinal Plexuses in Response to Hyperoxia. Ophthalmol Retina 2017; 2:329-336. [PMID: 29888339 DOI: 10.1016/j.oret.2017.07.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Purpose Use projection-resolved OCT angiography to investigate the autoregulatory response in the 3 parafoveal retinal plexuses under hyperoxia. Design Prospective cohort study. Participants Nine eyes from 9 healthy participants. Methods One eye from each participant was scanned using a commercial spectral-domain OCT system. Two repeated macular scans (3 × 3 mm2) were acquired at baseline and during oxygen breathing. The split-spectrum amplitude-decorrelation algorithm was used to detect blood flow. The projection-resolved algorithm was used to suppress projection artifacts and resolve blood flow in 3 distinct parafoveal plexuses. The Wilcoxon signed-rank test was used to compare baseline and hyperoxic parameters. The coefficient of variation, intraclass correlation coefficient, and pooled standard deviation were used to assess the reliability of OCT angiography measurements. Main Outcome Measures Flow index and vessel density were calculated from the en face angiograms of each of the 3 plexuses, as well as from the all-plexus inner retinal slab. Results Hyperoxia induced significant reduction in the flow index (-11%) and vessel density (-7.8%) of only the deep capillary plexus (P < 0.001) and in the flow index of the all-plexus slab (P = 0.015). The flow index also decreased in the intermediate capillary plexus and the superficial vascular complex, but these changes were small and not statistically significant. The projection-resolved OCT angiography showed good within-session baseline repeatability (coefficient of variation, 0.8%-5.2%; intraclass correlation coefficient, 0.93-0.98) in all parameters. Relatively large between-day response reproducibility was observed (pooled standard deviation, 1.7%-9.4%). Conclusions Projection-resolved OCT angiography was able to show that the retinal autoregulatory response to hyperoxia affects only the deep capillary plexus, but not the intermediate capillary plexus or superficial vascular complex.
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Reactivity in the human retinal microvasculature measured during acute gas breathing provocations. Sci Rep 2017; 7:2113. [PMID: 28522835 PMCID: PMC5437020 DOI: 10.1038/s41598-017-02344-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/10/2017] [Indexed: 11/11/2022] Open
Abstract
Although changes in vessel diameter following gas perturbation have been documented in retinal arterioles and venules, these responses have yet to be quantified in the smallest vessels of the human retina. Here, using in vivo adaptive optics, we imaged 3–25 µm diameter vessels of the human inner retinal circulation and monitored the effects of altered gas-breathing conditions. During isocapnic hyperoxia, definite constrictions were seen in 51% of vessel segments (mean ± SD for pre-capillary arterioles −9.5 ± 3.0%; capillaries −11.8 ± 3.3%; post-capillary venules −6.3 ± 2.8%); these are comparable with responses previously reported in larger vessels. During isoxic hypercapnia, definite dilations were seen in 47% of vessel segments (mean ± SD for pre-capillary arterioles +9.8 ± 1.5%; capillaries +13.7 ± 3.8%; post-capillary venules +7.5 ± 4.2%); these are proportionally greater than responses previously reported in larger vessels. The magnitude of these proportional changes implies that the capillary beds themselves play an important role in the retinal response to changes in carbon dioxide levels. Interestingly, the distribution of microvascular responses shown here differs from our previously reported responses to flicker stimulation, suggesting differences in the way blood supply is coordinated following gas perturbation and altered neural activity.
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Linsenmeier RA, Zhang HF. Retinal oxygen: from animals to humans. Prog Retin Eye Res 2017; 58:115-151. [PMID: 28109737 DOI: 10.1016/j.preteyeres.2017.01.003] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 01/13/2017] [Accepted: 01/17/2017] [Indexed: 10/20/2022]
Abstract
This article discusses retinal oxygenation and retinal metabolism by focusing on measurements made with two of the principal methods used to study O2 in the retina: measurements of PO2 with oxygen-sensitive microelectrodes in vivo in animals with a retinal circulation similar to that of humans, and oximetry, which can be used non-invasively in both animals and humans to measure O2 concentration in retinal vessels. Microelectrodes uniquely have high spatial resolution, allowing the mapping of PO2 in detail, and when combined with mathematical models of diffusion and consumption, they provide information about retinal metabolism. Mathematical models, grounded in experiments, can also be used to simulate situations that are not amenable to experimental study. New methods of oximetry, particularly photoacoustic ophthalmoscopy and visible light optical coherence tomography, provide depth-resolved methods that can separate signals from blood vessels and surrounding tissues, and can be combined with blood flow measures to determine metabolic rate. We discuss the effects on retinal oxygenation of illumination, hypoxia and hyperoxia, and describe retinal oxygenation in diabetes, retinal detachment, arterial occlusion, and macular degeneration. We explain how the metabolic measurements obtained from microelectrodes and imaging are different, and how they need to be brought together in the future. Finally, we argue for revisiting the clinical use of hyperoxia in ophthalmology, particularly in retinal arterial occlusions and retinal detachment, based on animal research and diffusion theory.
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Affiliation(s)
- Robert A Linsenmeier
- Biomedical Engineering Department, Northwestern University, 2145 Sheridan Road, Evanston 60208-3107, IL, USA; Neurobiology Department, Northwestern University, 2205 Tech Drive, Evanston 60208-3520, IL, USA; Ophthalmology Department, Northwestern University, 645 N. Michigan Ave, Suite 440, Chicago 60611, IL, USA.
| | - Hao F Zhang
- Biomedical Engineering Department, Northwestern University, 2145 Sheridan Road, Evanston 60208-3107, IL, USA; Ophthalmology Department, Northwestern University, 645 N. Michigan Ave, Suite 440, Chicago 60611, IL, USA.
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