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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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2
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Ikemura T, Nakamura N, Hayashi N. Impact of acute dynamic exercise on vascular stiffness in the retinal arteriole in healthy subjects. J Appl Physiol (1985) 2021; 132:459-468. [PMID: 34941440 DOI: 10.1152/japplphysiol.00507.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acute exercise can improve vascular stiffness in the conduit artery, but its effect on the retinal arterioles is unknown. The present study investigated the effects of acute dynamic exercise on retinal vascular stiffness. In experiment 1, we measured the cardio-ankle vascular index (CAVI), carotid artery intima-media thickness (carotid IMT), and retinal blood velocity by laser speckle flowgraphy in 28 healthy old and 28 young men (69 ± 3 and 23 ± 3 years, respectively). Pulse waveform variables, which were used as an index of retinal vascular stiffness, were assessed by retinal blood flow velocity profile analysis. In experiment 2, 18 healthy old and 18 young men (69 ± 3 and 23 ± 3 years, respectively) underwent assessment of pulse waveform variables after a 30-min bout of moderate cycling exercise at an intensity of 60% heart rate reserve. There was a significant difference in the baseline pulse waveform variables between the old and young groups. Pulse waveform variables in the retinal arteriole did not significantly change after acute dynamic exercise, whereas CAVI significantly decreased. These findings suggest that retinal vascular stiffness does not change by acute exercise. The effect of exercise on vascular stiffness in the retinal arterioles might be different from that in the conduit artery.
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Affiliation(s)
- Tsukasa Ikemura
- College of Liberal Arts and Science, Kitasato University, Kitazato, Minami-ku, Sagamihara, Kanagawa, Japan.,Faculty of Commerce, Yokohama College of Commerce, Higashiterao, Tsurumi, Yokohama, Kanagawa, Japan.,Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | - Nobuhiro Nakamura
- Faculty of Commerce, Yokohama College of Commerce, Higashiterao, Tsurumi, Yokohama, Kanagawa, Japan.,Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | - Naoyuki Hayashi
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan.,Institute for Liberal Arts, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo, Japan
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3
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Krzyżanowska-Berkowska P, Czajor K, Iskander DR. Associating the biomarkers of ocular blood flow with lamina cribrosa parameters in normotensive glaucoma suspects. Comparison to glaucoma patients and healthy controls. PLoS One 2021; 16:e0248851. [PMID: 33755663 PMCID: PMC7987161 DOI: 10.1371/journal.pone.0248851] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 03/07/2021] [Indexed: 11/18/2022] Open
Abstract
Purpose To evaluate association between ocular blood flow biomarkers and lamina cribrosa parameters in normotensive glaucoma suspects compared to glaucoma patients and healthy controls. Methods A total of 211 subjects (72 normotensive glaucoma suspects, 70 with primary open-angle glaucoma and 69 controls) were included. Ocular blood flow biomarkers in ophthalmic artery, central retinal artery, as well as in nasal and temporal short posterior ciliary arteries were measured using colour Doppler imaging. Lamina cribrosa position was assessed by measuring its depth, deflection depth, lamina cribrosa shape index and its horizontal equivalent (LCSIH) on B-scan images obtained using optical coherence tomography. Results Ocular blood flow biomarkers in glaucoma patients were statistically significantly reduced when compared to healthy controls in peak systolic velocity (PSV) (P = 0.001 in ophthalmic artery and P<0.001 in central retinal artery) and mean flow velocity (Vm) (P = 0.008 in ophthalmic artery and P = 0.008 in central retinal artery), but not statistically significantly different to that of glaucoma suspects except for PSV in central retinal artery (P = 0.011). Statistically significant correlations corrected for age, central corneal thickness and intraocular pressure were found in glaucoma patients between LCSIH and end diastolic velocity of central retinal artery (P = 0.011), and of nasal short posterior ciliary artery (P = 0.028), and between LCSIH and Vm of central retinal artery (P = 0.011) and of nasal short posterior ciliary artery (P = 0.007). No significant correlations were observed between these parameters in glaucoma suspects and healthy controls. Conclusions Impaired ocular blood flow associated with the deformation of lamina cribrosa was found in glaucoma patients, whereas glaucoma suspects had similar lamina cribrosa shape to glaucoma patients but that deformation was not associated with ocular blood flow biomarkers.
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Affiliation(s)
| | - Karolina Czajor
- Department of Ophthalmology, Wroclaw Medical University, Wroclaw, Poland
| | - D. Robert Iskander
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
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4
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Szegedi S, Hommer N, Kallab M, Puchner S, Schmidl D, Werkmeister RM, Garhöfer G, Schmetterer L. Repeatability and Reproducibility of Total Retinal Blood Flow Measurements Using Bi-Directional Doppler OCT. Transl Vis Sci Technol 2020; 9:34. [PMID: 32832239 PMCID: PMC7414639 DOI: 10.1167/tvst.9.7.34] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/28/2020] [Indexed: 12/01/2022] Open
Abstract
Purpose To investigate the repeatability and reproducibility of total retinal blood flow measurements using a custom-built dual-beam bidirectional Doppler optical coherence tomography (OCT) system in healthy subjects. Methods Repeatability and reproducibility were analyzed in 10 and 34 healthy subjects, respectively. For repeatability, measurements were taken twice within 30 minutes, for reproducibility, twice within two to five weeks. Two analysis approaches were compared for calculation of absolute blood velocities: a previously published approach resulting in values for total arterial (QA,abs) and total venous blood flow (QV,abs) and a novel approach taking into account that there is a fixed relation between the phase shift in the two OCT channels (QA,new, QV,new). Repeatability and reproducibility were quantified using intraclass correlation coefficients (ICCs). Results For QA,abs and QV,abs, ICC values between 0.78 and 0.84 were obtained. QA,new and QV,new values revealed better repeatability and reproducibility as compared to the convential appoach. Repeatability ICCs for QA,new and QV,new were between 0.91 and 0.93, and reproducibility ICCs were between 0.87 and 0.91 indicating excellent reproducibility. Good agreement was observed between total retinal blood flow values as measured from retinal arteries and retinal veins. Conclusions Measurement of total retinal blood flow using dual-beam Doppler OCT shows excellent reproducibility, which can further be improved by using a novel algorithm for calculating blood velocities in retinal vessels. Translational Relevance Our data indicate that dual-beam Doppler OCT can be used for longitudinal studies. Hence, quantitative retinal blood flow may be established as a biomarker for progression vascular eye diseases.
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Affiliation(s)
- Stephan Szegedi
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Nikolaus Hommer
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Martin Kallab
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Stefan Puchner
- Department of Clinical Pharmacology, Medical University of Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - René M Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University of Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE), Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore.,Institute of Clinical and Experimental Ophthalmology, Basel, Switzerland
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5
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Bata AM, Fondi K, Szegedi S, Aschinger GC, Hommer A, Schmidl D, Chua J, Werkmeister RM, Garhöfer G, Schmetterer L. Age-Related Decline of Retinal Oxygen Extraction in Healthy Subjects. Invest Ophthalmol Vis Sci 2019; 60:3162-3169. [PMID: 31335953 DOI: 10.1167/iovs.18-26234] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the age-dependence of total retinal blood flow and total retinal oxygen extraction in healthy subjects and determine their possible correlations with structural optical coherence tomography (OCT) parameters. Methods This observational cross-sectional study consisted of 68 healthy subjects (mean ± SD age, 45.6 ± 16.3 years; 47% female). Total retinal oxygen extraction was calculated based on measurement of total retinal blood flow using bi-directional Doppler OCT and measurement of oxygen saturation using spectroscopic reflectometry. Retinal nerve fiber layer thickness was measured using OCT, and the total number of retinal ganglion cells was estimated based on a previous published model. Correlation of these parameters with age was studied and the association between structural OCT parameters and hemodynamic vascular parameters was calculated. Results Both structural and vascular parameters showed a significant decline with increasing age. The correlation coefficients were between r = -0.25 and r = -0.41. Furthermore, structural and vascular parameters were significantly correlated with each other. The strongest association was found between the level of total retinal oxygen extraction and the number of retinal ganglion cells (r = 0.75, P < 0.001). Conclusions We showed that there was an age-related decline of retinal oxygen extraction. Levels of retinal oxygen extraction are correlated to retinal nerve fiber layer thickness and number of retinal ganglion cells. Our data partially explain the wide inter-individual variability in retinal blood flow values in healthy subjects. Longitudinal studies are required to study the time course of vascular and neuronal loss in humans.
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Affiliation(s)
- Ahmed M Bata
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Klemens Fondi
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Stephan Szegedi
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Gerold C Aschinger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Anton Hommer
- Department of Clinical Pharmacology, Medical University of Vienna, Austria.,Department of Ophthalmology, Sanatorium Hera, Vienna, Austria
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - René M Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University of Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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6
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Age-related changes in retrobulbar circulation: a literature review. Int Ophthalmol 2019; 40:493-501. [DOI: 10.1007/s10792-019-01176-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 09/19/2019] [Indexed: 12/28/2022]
Abstract
Abstract
Introduction
The advances in research methods used in ophthalmology allow for an increasingly accurate examination of the eyes, as well as the morphology and function of the vessels. Colour Doppler imaging is still the first-line method for the analysis of parameters of retrobulbar circulation. Therefore, the aim of this work was to present the current state of knowledge about anatomical and functional age-related changes in retrobulbar arteries.
Methods
A literature search was performed mainly based on the PubMed database.
Results
The anatomy of retrobulbar arteries, histological background of age-related vascular changes, age-related changes in retrobulbar blood flow in the ophthalmic artery, central retinal artery, short posterior ciliary arteries, and the reference values for the age-dependent retrobulbar circulation parameters measured by colour Doppler imaging are discussed in this review.
Conclusion
The age of the subject should always be taken into account when interpreting the parameters of retrobulbar blood flow measured by colour Doppler imaging.
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7
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Novel morphometric analysis of higher order structure of human radial peri-papillary capillaries: relevance to retinal perfusion efficiency and age. Sci Rep 2019; 9:13464. [PMID: 31530831 PMCID: PMC6748979 DOI: 10.1038/s41598-019-49443-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 08/24/2019] [Indexed: 11/30/2022] Open
Abstract
We apply novel analyses to images of superficial capillaries that are located near and around the optic disc of the human retina: the radial peri-papillary capillaries (RPCs). Due to their unique perfusion of the nerve fibre layer the RPCs are particularly significant for optic-neuropathies. The inputs to the analysis were z-stacks from 3D confocal fluorescence microscopy from 62 human retinas aged 9 to 84 years. Our aim was to find morphometric correlates of age. The retinas had no ophthalmic history. The analysis was undertaken in two stages: (1) converting the z-stacks to 3D tubular networks of vessels, and (2) characterizing the tubular networks using features derived from the Minkowski functionals (MFs). The MFs measure: the capillary volume, surface area, mean breadth, and Euler number. The mean breadth is related to tortuosity, wall shear stress and resistance to flow, and the Euler number is related to the density of loops (collaterals). Features derived from the surface area, mean breadth and Euler number were most related to age (all p ≤ 0.006). The results indicate the importance of pressure-equalizing loops and tortuosity as quantitative measures related to perfusion efficiency. The novel morphometric analysis could quantify disease-related accelerated aging and vessel malformation.
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Chua J, Schwarzhans F, Nguyen DQ, Tham YC, Sia JT, Lim C, Mathijia S, Cheung C, Tin A, Fischer G, Cheng CY, Vass C, Schmetterer L. Compensation of retinal nerve fibre layer thickness as assessed using optical coherence tomography based on anatomical confounders. Br J Ophthalmol 2019; 104:282-290. [PMID: 31118184 PMCID: PMC7025730 DOI: 10.1136/bjophthalmol-2019-314086] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/04/2019] [Accepted: 04/27/2019] [Indexed: 01/07/2023]
Abstract
Background/Aims To compensate the retinal nerve fibre layer (RNFL) thickness assessed by spectral-domain optical coherence tomography (SD-OCT) for anatomical confounders. Methods The Singapore Epidemiology of Eye Diseases is a population-based study, where 2698 eyes (1076 Chinese, 704 Malays and 918 Indians) with high-quality SD-OCT images from individuals without eye diseases were identified. Optic disc and macular cube scans were registered to determine the distance between fovea and optic disc centres (fovea distance) and their respective angle (fovea angle). Retinal vessels were segmented in the projection images and used to calculate the circumpapillary retinal vessel density profile. Compensated RNFL thickness was generated based on optic disc (ratio, orientation and area), fovea (distance and angle), retinal vessel density, refractive error and age. Linear regression models were used to investigate the effects of clinical factors on RNFL thickness. Results Retinal vessel density reduced significantly with increasing age (1487±214 µm in 40–49, 1458±208 µm in 50–59, 1429±223 µm in 60–69 and 1415±233 µm in ≥70). Compensation reduced the variability of RNFL thickness, where the effect was greatest for Chinese (10.9%; p<0.001), followed by Malays (6.6%; p=0.075) and then Indians (4.3%; p=0.192). Compensation reduced the age-related RNFL decline by 55% in all participants (β=−3.32 µm vs β=−1.50 µm/10 years; p<0.001). Nearly 62% of the individuals who were initially classified as having abnormally thin RNFL (outside the 99% normal limits) were later reclassified as having normal RNFL. Conclusions RNFL thickness compensated for anatomical parameters reduced the variability of measurements and may improve glaucoma detection, which needs to be confirmed in future studies.
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Affiliation(s)
- Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Florian Schwarzhans
- Section for Medical Information Management and Imaging, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Duc Quang Nguyen
- Ocular Epidemiology Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Yih Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Josh Tjunrong Sia
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Claire Lim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Shivani Mathijia
- Ocular Epidemiology Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Carol Cheung
- Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Ma Liu Shui, Hong Kong
| | - Aung Tin
- Singapore National Eye Centre, Singapore, Singapore
| | - Georg Fischer
- Section for Medical Information Management and Imaging, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Ching-Yu Cheng
- Ocular Epidemiology Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Clemens Vass
- Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
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Onishi AC, Nesper PL, Roberts PK, Moharram GA, Chai H, Liu L, Jampol LM, Fawzi AA. Importance of Considering the Middle Capillary Plexus on OCT Angiography in Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2019; 59:2167-2176. [PMID: 29801151 PMCID: PMC5915112 DOI: 10.1167/iovs.17-23304] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Purpose To quantify microvasculature changes in the superficial (SCP), middle (MCP), and deep capillary plexuses (DCP) in diabetic retinopathy (DR). Methods Retrospective cross-sectional study at a tertiary academic referral center, in which 26 controls (44 eyes), 27 diabetic subjects without retinopathy (44 eyes), 32 subjects with nonproliferative retinopathy (52 eyes), and 27 subjects with proliferative retinopathy (40 eyes) were imaged with optical coherence tomography angiography (OCTA). Outcome measures included parafoveal vessel density (VD), percentage area of nonperfusion (PAN), and adjusted flow index (AFI) at the different plexuses. Results MCP VD and MCP AFI decreased with worsening DR, while PAN increased, mirroring changes within the DCP. The fitted regression line for MCP and DCP AFI were significantly different than the SCP, while DCP PAN differed from SCP PAN with disease progression. Higher SCP AFI and PAN were different in eyes with diabetes without retinopathy compared with controls. Unexpectedly, sex was found to independently influence MCP VD and AFI with worsening disease. Conclusions OCTA parameters in the MCP and DCP displayed parallel changes with DR progression, different from the SCP, emphasizing the importance of physiologic considerations in the retinal capillaries. Thus, segmentation protocols that include the MCP within the SCP may be confounded. A difference in DCP PAN with worsening DR was unmasked relative to a prior study that included the MCP with SCP. We confirm that SCP AFI and PAN may serve as early indicators of microvascular changes in DR and identify an interaction between sex and the MCP deserving further study.
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Affiliation(s)
- Alex C Onishi
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States
| | - Peter L Nesper
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States
| | - Philipp K Roberts
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States.,Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Ganna A Moharram
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States
| | - Haitao Chai
- Department of Preventive Medicine, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States.,Institute for Financial Studies, Shandong University, Jinan, China
| | - Lei Liu
- Department of Preventive Medicine, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States
| | - Lee M Jampol
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States
| | - Amani A Fawzi
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States
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10
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Miyaji A, Ikemura T, Hayashi N. Aging decreases CO2 reactivity in the retinal artery, but not in the ocular choroidal vessels; a cross-sectional study. Clin Hemorheol Microcirc 2018; 70:231-240. [PMID: 29710683 DOI: 10.3233/ch-170332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The CO2 reactivity is often used to assess vascular function, but it is still unclear whether this reactivity is affected by aging. OBJECTIVE To investigate the effects of aging on the CO2 reactivity in ocular and cerebral vessels, both of which are highly sensitive to hypercapnia, we compared the CO2 reactivity in the retinal artery (RA), retinal and choroidal vessels (RCV), optic nerve head (ONH), and middle cerebral artery (MCA) between young and middle-aged subjects. METHODS We measured the CO2 reactivity in 14 young and 11 middle-aged males using laser-speckle flowgraphy during a 3-min inhalation of CO2-rich air. RESULTS The CO2 reactivity in the RA and ONH were lower in the middle-aged group than in the young group, but no significant effect of age was observed in the RCV or MCA. The CO2 reactivity in the RA and ONH were correlated significantly with age, whereas those in the RCV or MCA were not. CONCLUSIONS These findings suggest that there are regional differences in the effect of age on the CO2 reactivity among not only ocular and cerebral vessels, but also the retinal and choroidal vessels, even though these vessels are in neighboring areas.
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Affiliation(s)
- Akane Miyaji
- Division of Medical Nutrition, Faculty of Healthcare, Tokyo Healthcare University, Setagaya, Tokyo, Japan.,Graduate School of Decision Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo, Japan
| | - Tsukasa Ikemura
- Department of Management Information, Yokohama College of Commerce, Yokohama, Kanagawa, Japan
| | - Naoyuki Hayashi
- Graduate School of Decision Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo, Japan.,Institute for Liberal Arts, Tokyo Institute of Technology, Meguro, Tokyo, Japan
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11
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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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12
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Ling JW, Yin X, Lu QY, Chen YY, Lu PR. Optical coherence tomography angiography of optic disc perfusion in non-arteritic anterior ischemic optic neuropathy. Int J Ophthalmol 2017; 10:1402-1406. [PMID: 28944200 DOI: 10.18240/ijo.2017.09.12] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 05/11/2017] [Indexed: 12/16/2022] Open
Abstract
AIM To compare the optic disc blood flow of non-arteritic ischemic optic neuropathy (NAION) eyes with normal eyes. METHODS The optic disc blood flow densities of diagnosed non-acute phase NAION eyes (21 eyes, 14 individuals) and normal eyes (19 eyes, 12 individuals) were detected via Optovue optical coherence tomography angiography (OCTA). The optic disc blood flow was measured via Image J software. Correlations between optic disc perfusion and visual function variables were assessed by linear regression analysis. RESULTS The average percentage of the optic disc non-perfusion areas in the non-acute phase NAION patients (17.84%±6.18%) was increased, when compared to the normal control eyes (8.61%±1.65%), and the difference was statistically significant (P<0.01). Moreover, there was a proportional correlation between the visual field mean defect (MD) and the optic disc non-perfusion area percentage, and the relationship was statistically significant (t=3.65, P<0.01, R2=0.4118). In addition, the critical correlation between the best corrected visual acuity (BCVA) and the optic disc non-perfusion area percentage was statistically significant (t=4.32, P<0.01, R2=0.4957). CONCLUSION The optic disc non-perfusion area percentages detected via OCTA in NAION eyes were significantly increased when compared with the normal eyes. Both the BCVA and MD were correlated with the optic disc flow detected, revealing that OCTA may be valuable in the diagnosis and estimation of NAION.
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Affiliation(s)
- Jia-Wen Ling
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China.,Department of Ophthalmology, the Third People's Hospital of Zhangjiagang, Zhangjiagang 215600, Jiangsu Province, China
| | - Xue Yin
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China
| | - Qian-Yi Lu
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China
| | - Yi-Yi Chen
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China
| | - Pei-Rong Lu
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China
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Aizawa N, Kunikata H, Nitta F, Shiga Y, Omodaka K, Tsuda S, Nakazawa T. Age- and Sex-Dependency of Laser Speckle Flowgraphy Measurements of Optic Nerve Vessel Microcirculation. PLoS One 2016; 11:e0148812. [PMID: 26872348 PMCID: PMC4752292 DOI: 10.1371/journal.pone.0148812] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/22/2016] [Indexed: 11/04/2022] Open
Abstract
Purpose To investigate the relationship between various characteristics of a normal population and laser speckle flowgraphy (LSFG) measurements of mean blur rate (MBR) in the optic nerve head (ONH). Methods A total of 189 eyes of 189 normal subjects (93 male, 96 female, mean age 45 ± 14 years old, age range: 20–72) without any history of hypertension, hyperlipidemia or diabetes were enrolled. ONH microcirculation was measured with LSFG and overall MBR (MA), vessel-area MBR (MV), and tissue-area MBR (MT) were derived from these measurements. The statistical association of these measurements with characteristics such as sex, age, intraocular pressure (IOP) and systolic blood pressure (SBP) was then determined. Results There was a trend towards decreased IOP and MV and increased SBP with age (P = 0.002, P = 0.035, and P = 0.006, respectively). Furthermore, IOP, MV and SBP were correlated with age (r = -0.23, P = 0.011; r = -0.24, P < 0.001; and r = 0.30, P < 0.001, respectively). Separate multiple regression analyses of independent contributing factors revealed that sex and IOP contributed to MA (P < 0.001 and P = 0.002, respectively), sex, IOP, and age contributed to MV (P < 0.001, P = 0.003, and P = 0.024, respectively), while only IOP contributed to MT (P = 0.003). Conclusion In a normal population, MBR was affected by IOP in both the large vessel and capillary areas of the ONH, but not by SBP. MV was also affected by age and sex, while MT was stable independent of age or sex.
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Affiliation(s)
- Naoko Aizawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroshi Kunikata
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
- * E-mail:
| | - Fumihiko Nitta
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yukihiro Shiga
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kazuko Omodaka
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Satoru Tsuda
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
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Kuroda Y, Uji A, Yoshimura N. Factors associated with optic nerve head blood flow and color tone: a retrospective observational study. Graefes Arch Clin Exp Ophthalmol 2016; 254:963-70. [PMID: 26728756 DOI: 10.1007/s00417-015-3247-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 12/09/2015] [Accepted: 12/16/2015] [Indexed: 10/22/2022] Open
Abstract
PURPOSE To investigate the relationship between optic nerve head (ONH) blood flow and color tone. METHODS Retrospective observational study conducted between February 2014 and August 2014. We examined 29 eyes of 17 young healthy subjects and 37 eyes of 26 cataract patients undergoing cataract surgery. Blood flow was measured using laser speckle flowgraphy, and color tone was quantified using the public domain ImageJ software. Blood flow and color tone of the ONH before and after cataract surgery were compared. The influence of age, axial length, and color tone on ONH blood flow were also investigated. RESULTS Mean blur rate (MBR) in the ONH decreased with increasing age (R = -0.437, P < 0.001) and axial length (R = -0.306, P = 0.012). In young subjects, ONH redness had a moderate positive correlation with MBR (R = 0.376, P = 0.044); however, this correlation was not observed in the study population as a whole (R = 0.066, P = 0.601). MBR in the ONH was higher after cataract surgery (P < 0.001). Moreover, the ONH redness reduced postoperatively from that preoperatively (P < 0.001). An increase in MBR after cataract surgery correlated with improved visual acuity (R = -0.399, P = 0.014) and decreased redness the of ONH (R = -0.433, P < 0.01). CONCLUSIONS Ocular blood flow decreased in older people and in myopic eyes. The reddish appearance of the ONH was not an indicator of a circulatory condition, particularly in older people. Lens opacity appeared to underestimate hemodynamic quantification using laser speckle flowgraphy.
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Affiliation(s)
- Yoshimasa Kuroda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Akihito Uji
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Nagahisa Yoshimura
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, 606-8507, Japan
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15
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Asejczyk-Widlicka M, Krzyzanowska-Berkowska P, Sander BP, Iskander DR. Age-Related Changes in Ocular Blood Velocity in Suspects with Glaucomatous Optic Disc Appearance. Comparison with Healthy Subjects and Glaucoma Patients. PLoS One 2015. [PMID: 26218249 PMCID: PMC4517907 DOI: 10.1371/journal.pone.0134357] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Purpose To evaluate retrobulbar blood flow characteristics of glaucoma suspects with glaucomatous optic disc appearance (GODA) in comparison to healthy control group (CG) and primary open angle glaucoma patients (POAG) and assess the effect of age. Methods 145 patients from a single glaucoma clinic were enrolled and classified into two diagnostic groups (GODA and POAG). Third group of subjects consisted of 67 age matched individuals (CG). Retrobulbar blood velocity measurement in central retinal artery was performed using color Doppler imaging (CDI). CDI images were processed in custom software leading a range of parameter estimates from a continuous waveform signal. The effect of age on the estimated parameters was evaluated with the stepwise forward regression and ANCOVA in which age was used as a continuous factor. One-way ANOVA was used to test for the differences in the CDI parameters between the three considered groups. Correlation between restive index (RI) and pulsatility index (PI) was assessed with a bilinear fitting guaranteeing no discontinuities in RI intercept estimate. Fisher test was used to assess the applicability of a bilinear PI/RI relationship, while the statistics of the RI intercept estimate were evaluated using the bootstrap. Results ANCOVA showed significant interaction between age and group (p<0.05) for five out of nine considered CDI parameters. The RI intercept for CG and GODA groups was 0.602±0.047, and 0.574±0.044 respectively, while the RI intercept of 0.934±0.066 was found for the POAG. Conclusions The observed similarity of CG and GODA group and dissimilarity between GODA and POAG groups in terms of PI/RI relationship is remarkable. Age may play some role in the different mechanisms occurring in blood velocity dynamics in GODA and POAG subjects but it is not a strongly determining factor.
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Affiliation(s)
| | | | - Beata P. Sander
- Queensland University of Technology, School of Optometry, Brisbane, Australia
| | - D. Robert Iskander
- Department of Biomedical Engineering, Wroclaw University of Technology, Wroclaw, Poland
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16
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Chandra P, Sudhalkar A, Mandal S, Chhablani J. Retinal circulation and its role in macular disorders in patients without systemic disease. Int J Ophthalmol 2015; 8:585-9. [PMID: 26086013 DOI: 10.3980/j.issn.2222-3959.2015.03.27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 08/22/2014] [Indexed: 11/02/2022] Open
Abstract
AIM To determine whether retinal circulatory changes play a role in the pathogenesis of macular disorders in patients who are otherwise healthy. METHODS Patients with macular disorders that required angiographic imaging were included in this prospective case series. After a complete ocular exam, fluorescein angiography was performed using a standardized technique on the HRA-II (Heidelberg Engineering, Heidelberg, Germany) with special focus on the posterior pole. Only patients with good quality images were included in the analysis. Circulatory parameters recorded included the arm-choroid time, choroid-retinal artery, and finally the retinal artery-vein time. Zonal asymmetry (between the upper and lower zones divided by a line passing through the centre of the fovea) in transit times, if any was also noted. Appropriate statistical analysis was done. Circulation times were compared with age matched historical controls. Changes in retinal dye transit times relative to historical age matched controls, if any, were noted and compared between various disorders. RESULTS A total of 156 eyes of 156 patients (120 males) were included in the study. Mean age: 49.14±14.93y. Macular disorders studied were age related degeneration, polypoidal vasculopathy, central serous chorioretinopathy (CSCR) and parafoveal telangiectasia. Delayed circulation time was noted in CSCR patients only. CONCLUSION CSCR patients appear to have delayed arterial filling, retinal circulatory disturbances do not seem to contribute to the pathogenesis of other macular disorders.
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Affiliation(s)
- Priyangshu Chandra
- Smt. Kanuri Santhamma Retina Vitreous Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, L.V.Prasad Marg, Banjara Hills, Hyderabad, Andhra Pradesh 500034, India
| | - Aditya Sudhalkar
- Smt. Kanuri Santhamma Retina Vitreous Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, L.V.Prasad Marg, Banjara Hills, Hyderabad, Andhra Pradesh 500034, India
| | - Souvik Mandal
- Smt. Kanuri Santhamma Retina Vitreous Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, L.V.Prasad Marg, Banjara Hills, Hyderabad, Andhra Pradesh 500034, India
| | - Jay Chhablani
- Smt. Kanuri Santhamma Retina Vitreous Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, L.V.Prasad Marg, Banjara Hills, Hyderabad, Andhra Pradesh 500034, India
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17
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Feke GT, Hyman BT, Stern RA, Pasquale LR. Retinal blood flow in mild cognitive impairment and Alzheimer's disease. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2015; 1:144-51. [PMID: 27239502 PMCID: PMC4876882 DOI: 10.1016/j.dadm.2015.01.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Background Patients with Alzheimer's disease (AD) demonstrate the narrowing of retinal veins and decreased retinal venous blood flow compared with control subjects. We assessed whether these abnormalities are present in patients with mild cognitive impairment (MCI). Methods After the determination of the global clinical dementia rating, 52 subjects (10 AD, 21 MCI, and 21 normal controls) underwent retinal hemodynamic profiling. Blood column diameter, blood speed, and blood flow were measured in a major temporal retinal vein using retinal laser Doppler flowmetry. In addition, peripapillary retinal nerve fiber layer (RNFL) thickness was measured using optical coherence tomography. Results Blood column diameter in AD was narrower than in both MCI (P = .004) and controls (P = .002). However, blood speed in both AD (P = .024) and MCI (P = .005) was lower than in controls. As a result, the differences in blood flow between AD and MCI (P = .036), AD and controls (P < .0001), and MCI and controls (P = .009) were significant. Although there were no differences in RNFL thickness among the groups, blood flow was correlated (P = .047) with superior RNFL thickness in the AD group, but not in the MCI (P = .40) or control (P = .84) groups. Conclusions Retinal blood flow in MCI is intermediate between what is measured in control subjects and in AD patients. Our findings suggest that blood flow abnormalities may precede the neurodegeneration in AD.
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Affiliation(s)
- Gilbert T Feke
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical, School, Boston, MA, USA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Robert A Stern
- Department of Neurology, Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, USA
| | - Louis R Pasquale
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical, School, Boston, MA, USA; Department of Medicine, Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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18
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Srinivas S, Tan O, Wu S, Nittala MG, Huang D, Varma R, Sadda SR. Measurement of retinal blood flow in normal Chinese-American subjects by Doppler Fourier-domain optical coherence tomography. Invest Ophthalmol Vis Sci 2015; 56:1569-74. [PMID: 25670487 PMCID: PMC4351651 DOI: 10.1167/iovs.14-15038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE To measure total retinal blood flow (TRBF) in normal, healthy Chinese Americans by using semi-automated analysis of Doppler Fourier-domain optical coherence tomography (FD-OCT) scans. METHODS Two hundred sixty-six normal, healthy Chinese-American participants (266 eyes) were enrolled from The Chinese American Eye Study. All participants underwent complete ophthalmic examination, including best-corrected visual acuity, indirect ophthalmoscopy, and Doppler FD-OCT imaging, using the circumpapillary double circular scan protocol. Total retinal blood flow and other vascular parameters (e.g., venous and arterial cross-sectional area and their velocities) were calculated by using Doppler OCT of Retinal Circulation software. Associations between TRBF and other clinical parameters were assessed by using bivariate correlations and linear regression. RESULTS The mean age of study participants was 57.40 ± 5.60 (range, 50-82) years. The mean TRBF was 49.34 ± 10.08 (range, 27.17-78.08, 95% confidence interval: 25.98-69.10) μL/min. The mean venous area was 0.0548 (±0.0084) mm(2). Superior retinal hemispheric blood flow (25.50 ± 6.62 μL/min) was slightly greater than inferior retinal hemispheric blood flow (23.84 ± 7.19 μL/min, P = 0.008). The mean flow velocity was 15.16 ± 3.12 mm/s. There was a weak but significant negative correlation between TRBF and age (r = -0.15, P = 0.012). No significant correlation was found between TRBF and axial length (r = 0.11, P = 0.08). Retinal blood flow was not significantly correlated with any other clinical parameters, including body mass index, systolic blood pressure, diastolic blood pressure, and intraocular pressure. CONCLUSIONS Normal Doppler OCT-derived total retinal blood values in a Chinese-American population showed considerable variability, some of which was explained by age. These observations should help design future studies evaluating TRBF in populations with eye disease.
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Affiliation(s)
- Sowmya Srinivas
- Doppler OCT Reading Center, Doheny Eye Institute, Los Angeles, California, United States
| | - Ou Tan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Shuang Wu
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | | | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Rohit Varma
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States
| | - SriniVas R. Sadda
- Doppler OCT Reading Center, Doheny Eye Institute, Los Angeles, California, United States
,Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
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19
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Hammond BR, Johnson BA, George ER. Oxidative photodegradation of ocular tissues: beneficial effects of filtering and exogenous antioxidants. Exp Eye Res 2014; 129:135-50. [PMID: 25236792 DOI: 10.1016/j.exer.2014.09.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/11/2014] [Accepted: 09/13/2014] [Indexed: 01/17/2023]
Abstract
The fact that light is necessary for life is generally accepted as an axiom. The extent to which light interacts and influences human biology, however, is often not fully appreciated. Exposure to sunlight, for instance, can both promote and degrade human health. There is now general scientific consensus that, although the eye evolved to respond to light, it is also damaged by excessive exposure. Light-mediated ocular damage is involved in the pathophysiology of many common forms of blindness. The type of ocular tissue damage induced by light exposure depends on the extent of exposure and wavelength. The tissues of the lens, cornea, and retina contain specific chemical moieties that have been proven to exhibit light-mediated oxidative degradation. Proteins and lipids present in the cornea, lens, and retina, meet all of the physical requirements known to initiate the process of oxidative photodegradation upon exposure to solar radiation. As such, different mechanisms have evolved in the lens, cornea, and retina to ameliorate such light-mediated oxidative damage. It appears, however, that such mechanisms are ill-matched to handle modern conditions: namely, poor diet and longer life-spans (and the degenerative diseases that accompany them). Hence, steps must be taken to protect the eye from the damaging effects of light. Preventative measures include minimizing actinic light exposure, providing exogenous filtering (e.g., through the use of protective lenses), and enhancing antioxidant defenses (e.g., through increased dietary intake of antioxidants). These strategies may yield long-term benefits in terms of reducing oxidative photodegradation of the ocular tissues.
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Affiliation(s)
- Billy R Hammond
- Vision Sciences Laboratory, University of Georgia, Athens, GA 30602-3013, USA.
| | - Bart A Johnson
- Johnson & Johnson Vision Care, Inc., 7500 Centurion Parkway, R&D 3rd Floor W3A, Jacksonville, FL 33256, USA
| | - Eric R George
- Johnson & Johnson Vision Care, Inc., 7500 Centurion Parkway, R&D 3rd Floor W3A, Jacksonville, FL 33256, USA.
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20
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Modrzejewska M, Siesky B, Amireskandari A, Holland S, Grzesiak W, Zaborski D, Huck A, Harris A. Parameters Characterizing Age-Dependent Retrobulbar Circulation in Healthy Subjects Measured by Color Doppler Ultrasonography. Curr Eye Res 2014; 40:729-36. [DOI: 10.3109/02713683.2014.954675] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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21
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Lim JKH, Nguyen CTO, He Z, Vingrys AJ, Bui BV. The effect of ageing on ocular blood flow, oxygen tension and retinal function during and after intraocular pressure elevation. PLoS One 2014; 9:e98393. [PMID: 24866182 PMCID: PMC4035318 DOI: 10.1371/journal.pone.0098393] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 05/02/2014] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To investigate the effect of ageing on the recovery of ocular blood flow, intravitreal oxygen tension and retinal function during and after intraocular pressure (IOP) elevation. METHODS Long Evans rats (3- and 14-month-old) underwent acute stepwise IOP elevation from 10 to 120 mmHg (5 mmHg steps each 3 minutes). IOP was then returned to baseline and recovery was monitored for 2 hours. Photopic electroretinograms (ERG) were recorded at each IOP step during stress and at each minute during recovery. Ocular blood flow and vitreal oxygen tension (pO2) were assayed continuously and simultaneously using a combined laser Doppler flow meter (LDF) and an oxygen sensitive fibre-optic probe, respectively. The combined sensor was placed in the vitreous chamber, proximal to the retina. Data were binned into 3 minute intervals during stress and 1 min intervals during recovery. Recovery data was described using a bi-logistic function. RESULTS Rats of both ages showed similar susceptibility to IOP elevation, with pO2 showing a closer relationship to ERG than LDF. During recovery, both ages showed a distinctive two-phased recovery for all three measures with the exception of the LDF in 3-month-old rats, which showed only 1 phase. In all animals, LDF recovered fastest (<1 minute), followed by pO2 (<10 minute) and ERG (>1 hour). 14-month-old rats showed surprisingly faster and greater LDF recovery compared to the younger group, with similar levels of pO2 recovery. However, the ERG in these middle-aged animals did not fully recover after two hours, despite showing no difference in susceptibility to IOP during stress compared to the young group. CONCLUSIONS Young and middle-aged eyes showed similar susceptibility to IOP elevation in terms of pO2, LDF and ERG. Despite this lack of difference during stress, older eyes did not completely recover function, suggesting a more subtle age-related susceptibility to IOP.
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Affiliation(s)
- Jeremiah K. H. Lim
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - Christine T. O. Nguyen
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - Algis J. Vingrys
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - Bang V. Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
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Tsuda S, Kunikata H, Shimura M, Aizawa N, Omodaka K, Shiga Y, Yasuda M, Yokoyama Y, Nakazawa T. Pulse-waveform analysis of normal population using laser speckle flowgraphy. Curr Eye Res 2014; 39:1207-15. [PMID: 24749668 DOI: 10.3109/02713683.2014.905608] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Laser speckle flowgraphy (LSFG), a new, non-invasive method of measuring the mean blur rate (MBR) of ocular blood flow, allows for the analysis of the pulse waveform of a heartbeat as it changes dynamically. Here, we investigated the relationship between the pulse waveform and clinical parameters, particularly age. MATERIALS AND METHODS Sixty eyes of 60 healthy subjects without diabetes were enrolled from among patients undergoing annual health examinations. LSFG, and its analysis software, were used to determine pulse waveform parameters including MBR, skew, blowout score (BOS), blowout time (BOT), rising rate and falling rate in the optic nerve head (ONH), both specifically in the tissue area and in the ONH overall. Fifteen clinical parameters were also recorded, including age and blood pressure, as well as triglyceride and creatinine levels. RESULTS Skew, BOT and falling rate had a strong correlation (|r| > 0.60) with age, but not with the other clinical parameters. This correlation with age was stronger in the tissue area (BOT: p < 0.0001, r = - 0.68; skew: p < 0.0001, r = 0.65; falling rate: p < 0.0001, r = 0.61) than in the ONH overall (BOT: p < 0.0001, r = -0.67; skew: p < 0.0001, r = 0.60; falling rate: p < 0.0001, r = 0.59). Stepwise multiple regression analysis revealed that tissue area falling rate was an independent factor indicating age, and conversely that age was an independent factor indicating tissue area falling rate. CONCLUSIONS The significant correlation of LSFG-measured tissue area falling rate with age suggests that it may be a new candidate biomarker for age-dependent microcirculation.
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Affiliation(s)
- Satoru Tsuda
- Department of Ophthalmology, Tohoku University Graduate School of Medicine , Sendai, Miyagi , Japan and
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El-Sayyad HIH, Khalifa SA, El-Sayyad FI, Al-Gebaly AS, El-Mansy AA, Mohammed EAM. Aging-related changes of optic nerve of Wistar albino rats. AGE (DORDRECHT, NETHERLANDS) 2014; 36:519-532. [PMID: 23996059 PMCID: PMC4039266 DOI: 10.1007/s11357-013-9580-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 08/05/2013] [Indexed: 06/02/2023]
Abstract
Aging is a biological phenomenon that involves an increase of oxidative stress associated with gradual degradation of the structure and function of the optic nerve. Gender differences and subsequent deterioration of optic nerve are an interesting topic, especially because there is little published work concerning it. One hundred male and female Wistar albino rats' with ages 1, 6, 18, 24, and 30 months (n = 20 equal for male and female) were used. At the time interval, optic nerve was investigated by light and transmission electron microscopy (TEM), assessments of antioxidant enzymes (catalase, superoxide dismustase, and glutathione-S-transferase), caspase 3 and 7, malondialdhyde, flow cytometry of DNA, annexin v, and CD8, immunochemistry of vascular endothelial growth factor (VEGF), CD31, and CD45, and single-strand DNA fragmentation. Light and TEM observations of the older specimens (24 and 30 months) revealed apparent deterioration of optic nerve axons, abundant oligodendrocytes with pyknotic nuclei, swollen astrocytes, angiogenesis, vacuolar degeneration, and mitochondrial damage. Females were highly susceptible to aging processes. Concomitantly, there was a marked reduction of antioxidant's enzymes and an increase of lipid peroxidation and apoptotic markers. Old age exhibited a marked increase of G1 apoptosis, UR and LR of annexin V and CD8 as well as increased immuno-positive reaction with VEGR, CD31 and CD45. We conclude that aging contributed to an increase of oxidative stress resulting from damage of mitochondria in axons, oligodendrocytes, and astrocytes. Age-related loss of optic nerve axons is associated with multifactorial agents including reduction in antioxidant enzymes, disruption of vasculature, astrocyte, and oligodendrocyte, demyelination, and damage of mitochondria, which enhance the liberation of reactive oxygen species as assessed by an increase of apoptotic markers malondialdhyde and caspase 3 and 7.
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Affiliation(s)
- Hassan I H El-Sayyad
- Department of Zoology, Faculty of Science, Mansoura University, Mansoura, Egypt,
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Emeterio Nateras OS, Harrison JM, Muir ER, Zhang Y, Peng Q, Chalfin S, Gutierrez JE, Johnson DA, Kiel JW, Duong TQ. Choroidal blood flow decreases with age: an MRI study. Curr Eye Res 2014; 39:1059-67. [PMID: 24655028 DOI: 10.3109/02713683.2014.892997] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To verify that a visual fixation protocol with cued eye blinks achieves sufficient stability for magnetic resonance imaging (MRI) blood-flow measurements and to determine if choroidal blood flow (ChBF) changes with age in humans. METHODS The visual fixation stability achievable during an MRI scan was measured in five normal subjects using an eye-tracking camera outside the MRI scanner. Subjects were instructed to blink immediately after recorded MRI sound cues but to otherwise maintain stable visual fixation on a small target. Using this fixation protocol, ChBF was measured with MRI using a 3 Tesla clinical scanner in 17 normal subjects (24-68 years old). Arterial and intraocular pressures (IOP) were measured to calculate perfusion pressure in the same subjects. RESULTS The mean temporal fluctuations (standard deviation) of the horizontal and vertical displacements were 29 ± 9 μm and 38 ± 11 μm within individual fixation periods, and 50 ± 34 μm and 48 ± 19 μm across different fixation periods. The absolute displacements were 67 ± 31 μm and 81 ± 26 μm. ChBF was negatively correlated with age (R = -0.7, p = 0.003), declining 2.7 ml/100 ml/min per year. There were no significant correlations between ChBF versus perfusion pressure, arterial pressure, or IOP. There were also no significant correlations between age versus perfusion pressure, arterial pressure, or IOP. Multiple regression analysis indicated that age was the only measured independent variable that was significantly correlated with ChBF (p = 0.03). CONCLUSIONS The visual fixation protocol with cued eye blinks was effective in achieving sufficient stability for MRI measurements. ChBF had a significant negative correlation with age.
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Age-Related Macular Degeneration. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00065-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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26
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Burgansky-Eliash Z, Lowenstein A, Neuderfer M, Kesler A, Barash H, Nelson DA, Grinvald A, Barak A. The Correlation Between Retinal Blood Flow Velocity Measured by the Retinal Function Imager and Various Physiological Parameters. Ophthalmic Surg Lasers Imaging Retina 2013; 44:51-8. [DOI: 10.3928/23258160-20121221-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Accepted: 05/23/2012] [Indexed: 12/19/2022]
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Schultz T, Conrad-Hengerer I, Hengerer FH, Dick BH. Intraocular pressure variation during femtosecond laser–assisted cataract surgery using a fluid-filled interface. J Cataract Refract Surg 2013; 39:22-27. [DOI: 10.1016/j.jcrs.2012.10.038] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 10/05/2012] [Accepted: 10/11/2012] [Indexed: 02/03/2023]
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Nagaoka T, Sato E, Takahashi A, Sogawa K, Yokota H, Yoshida A. Effect of aging on retinal circulation in normotensive healthy subjects. Exp Eye Res 2009; 89:887-91. [PMID: 19664620 DOI: 10.1016/j.exer.2009.07.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 07/12/2009] [Accepted: 07/20/2009] [Indexed: 10/20/2022]
Abstract
Although it is important to investigate the effects of normal aging on the ocular circulation, few studies have examined the effects of aging on the retinal microcirculation in healthy subjects. The purpose of this study was to evaluate the effects of aging on the retinal microcirculation in healthy men. Forty-five healthy men were divided into three groups based on age (young, middle-aged, elderly). We measured vessel diameter and blood velocity and calculated the retinal blood flow (RBF) and wall shear rate (WSR) in the retinal arteries. We performed pulse wave analysis obtained from the retinal blood velocity measurements. We also divided the subjects into two groups based on the presence or absence of prehypertension defined as 120-139/80-89 mmHg. No significant differences in vessel diameter, blood velocity, RBF, and WSR were seen among the groups. Pulse wave analysis showed significant increases in upstroke time (UT) in elderly men compared with young men (P < 0.05). Multiple regression analysis showed that the UT was correlated with age in all subjects. A significant difference was seen only in the UT between subjects with and without prehypertension. The UT calculated from the retinal blood velocity profile is associated significantly with aging, suggesting that measurement of the UT may detect the changes in the retinal and the systemic vessels with increasing age. The UT is the only parameter that increased significantly in subjects with prehypertension compared with those without prehypertension, suggesting that the UT may indicate the effects of prehypertension on the retinal arterioles.
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Affiliation(s)
- Taiji Nagaoka
- Department of Ophthalmology, Asahikawa Medical College, 2-1-1-1 Midorigaoka Higashi, Asahikawa 078-8502, Japan.
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Ehrlich R, Kheradiya NS, Winston DM, Moore DB, Wirostko B, Harris A. Age-related ocular vascular changes. Graefes Arch Clin Exp Ophthalmol 2008; 247:583-91. [DOI: 10.1007/s00417-008-1018-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 11/19/2008] [Accepted: 11/24/2008] [Indexed: 10/21/2022] Open
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Ehrlich R, Harris A, Kheradiya NS, Winston DM, Ciulla TA, Wirostko B. Age-related macular degeneration and the aging eye. Clin Interv Aging 2008; 3:473-82. [PMID: 18982917 PMCID: PMC2682379 DOI: 10.2147/cia.s2777] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Age-related macular degeneration (AMD) is an ocular disease that causes damage to the retinal macula, mostly in the elderly. Normal aging processes can lead to structural and blood flow changes that can predispose patients to AMD, although advanced age does not inevitably cause AMD. In this review, we describe changes that occur in the macular structure, such as the retinal pigment epithelium and Bruch's membrane, with advancing age and in AMD. The role of genetics in AMD and age-related changes in ocular blood flow that may play a role in the pathogenesis of AMD are also discussed. Understanding the pathophysiology of AMD development can help guide future research to further comprehend this disease and to develop better treatments to prevent its irreversible central vision loss in the elderly.
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Affiliation(s)
- Rita Ehrlich
- Indiana University School of Medicine, Department of Ophthalmology, Indianapolis, IN 46202, USA
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Effect of Aging on Nocturnal Blood Flow in the Optic Nerve Head and Macula in Healthy Human Eyes. J Glaucoma 2008; 17:366-71. [DOI: 10.1097/ijg.0b013e31815d7838] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sahin FK, Koken G, Cosar E, Arioz DT, Degirmenci B, Albayrak R, Acar M. Effect of Aerodiol administration on ocular arteries in postmenopausal women. Gynecol Endocrinol 2008; 24:173-7. [PMID: 18382901 DOI: 10.1080/09513590701807431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVE The aim of the present study was to evaluate the alteration of ocular blood hemodynamics after intranasal administration of 17beta-estradiol, through measurement of the ophthalmic artery (OA) and the central retinal artery (CRA) using color duplex sonography. METHODS Thirty healthy women who had been naturally postmenopausal for at least 1 year were enrolled in the study. A randomized, placebo-controlled, crossover, double-blinded study was conducted of the acute effect of 17beta-estradiol (Aerodiol; Servier, Chambrayles-Tours, France) on OA and CRA blood flow using color duplex sonography. RESULTS The peak systolic and end diastolic velocities of the CRA were increased significantly after 17beta-estradiol administration compared with placebo. A significant decrease was also found in the pulsatility and resistive indices of the CRA. However, there were no statistically significant differences in OA flow velocities or pulsatility and resistive indices. CONCLUSIONS Nasal 17beta-estradiol administration in postmenopausal women causes an improvement in the ocular vascular Doppler indices. These results suggest that there could be a positive effect of Aerodiol on middle-sized arteries and arterioles.
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Affiliation(s)
- Figen Kir Sahin
- Department of Obstetrics and Gynecology, Kocatepe University Faculty of Medicine, Afyonkarahisar, Turkey.
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Riva CE, Schmetterer L. Microcirculation of the Ocular Fundus. Microcirculation 2008. [DOI: 10.1016/b978-0-12-374530-9.00018-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Bjärnhall G, Tomic L, Mishima HK, Tsukamoto H, Alm A. Retinal mean transit time in patients with primary open-angle glaucoma and normal-tension glaucoma. ACTA ACUST UNITED AC 2006; 85:67-72. [PMID: 17244213 DOI: 10.1111/j.1600-0420.2006.00780.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To compare the mean transit time (MTT) of retinal circulation in eyes with primary open-angle glaucoma (POAG) and eyes with normal-tension glaucoma (NTG) and examine the possible relationship between MTT and visual field damage, expressed as mean deviation (MD). METHODS Video fluorescein angiography was performed in 40 patients with POAG or NTG. Dye curves for fluorescein passing through the retinal arteries and veins were used to calculate MTT in each patient with a computer-assisted technique based on an impulse-response analysis (MTT(IR)). RESULTS We were able to analyse MTT(IR) in all 40 angiograms. Mean (SD) MTT(IR) was 5.0 (1.5) seconds in eyes with POAG and 4.7 (1.4) seconds in eyes with NTG. The difference was not statistically significant. There was a weak but significant correlation between the MD and MTT(IR) (MTT(IR) = 4.12-0.08*MD; r = -0.49, p = 0.0013). CONCLUSIONS The results demonstrate that loss of neuronal tissue in glaucoma is combined with an effect on the retinal circulation and that the effect is similar in eyes with NTG and eyes with POAG.
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Affiliation(s)
- Gunilla Bjärnhall
- Department of Neuroscience, Ophthalmology, Uppsala University, Uppsala, Sweden
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Patton N, Aslam T, Macgillivray T, Pattie A, Deary IJ, Dhillon B. Retinal vascular image analysis as a potential screening tool for cerebrovascular disease: a rationale based on homology between cerebral and retinal microvasculatures. J Anat 2005; 206:319-48. [PMID: 15817102 PMCID: PMC1571489 DOI: 10.1111/j.1469-7580.2005.00395.x] [Citation(s) in RCA: 518] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The retinal and cerebral microvasculatures share many morphological and physiological properties. Assessment of the cerebral microvasculature requires highly specialized and expensive techniques. The potential for using non-invasive clinical assessment of the retinal microvasculature as a marker of the state of the cerebrovasculature offers clear advantages, owing to the ease with which the retinal vasculature can be directly visualized in vivo and photographed due to its essential two-dimensional nature. The use of retinal digital image analysis is becoming increasingly common, and offers new techniques to analyse different aspects of retinal vascular topography, including retinal vascular widths, geometrical attributes at vessel bifurcations and vessel tracking. Being predominantly automated and objective, these techniques offer an exciting opportunity to study the potential to identify retinal microvascular abnormalities as markers of cerebrovascular pathology. In this review, we describe the anatomical and physiological homology between the retinal and cerebral microvasculatures. We review the evidence that retinal microvascular changes occur in cerebrovascular disease and review current retinal image analysis tools that may allow us to use different aspects of the retinal microvasculature as potential markers for the state of the cerebral microvasculature.
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Affiliation(s)
- Niall Patton
- Princess Alexandra Eye Pavilion, Chalmers Street, Edinburgh, UK.
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Fitzgerald MEC, Tolley E, Jackson B, Zagvazdin YS, Cuthbertson SL, Hodos W, Reiner A. Anatomical and functional evidence for progressive age-related decline in parasympathetic control of choroidal blood flow in pigeons. Exp Eye Res 2005; 81:478-91. [PMID: 15935343 DOI: 10.1016/j.exer.2005.03.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Revised: 03/15/2005] [Accepted: 03/20/2005] [Indexed: 11/21/2022]
Abstract
The choroid receives extensive parasympathetic innervation, which in birds arises largely from the ciliary ganglion (CG). Since age-related changes in parasympathetic regulation of choroidal blood flow (ChBF) could contribute to age-related retinal decline, we used anatomical and functional methods to determine if ChBF control by the CG shows age-related decline in pigeons. The efficacy of the choroidal vasodilatory response to activation of the CG preganglionic input from the medial subdivision of the nucleus of Edinger-Westphal (EWM) was assessed using laser Doppler flowmetry (LDF). The EWM receives bisynaptic retinal input, and electrical stimulation of EWM or light stimulation of the retina in young animals produces dramatic choroidal vasodilation. Transcleral LDF was therefore used to measure both basal ChBF and the increases in ChBF elicited by electrical stimulation of EWM or by retinal illumination in 0.5-18 year old pigeons. Fixed cryostat sections of the eye from 0.5 to 22 year old pigeons were immunolabeled for the 3A10 neurofilament-associated antigen to determine if intrachoroidal nerve fibers arising from CG exhibited age-related loss. We focused on superior choroid, since it is the primary target for CG nerve fibers. There was a marked age-related loss in the ChBF vasodilatory response elicited by either EWM stimulation or retinal illumination, as was also true for basal ChBF. A progressive decrease in choroidal nerve fibers of CG origin, to 17% of youthful abundance by 22 years of age, was also observed. The evoked ChBF increase, and basal ChBF, achieved 50% of their age-related decline between the ages of 3 and 4 years, while half the loss in CG innervation of choroid was later, occurring by 10 years. Age-related loss of choroidal nerve fibers occurs in parallel with but more slowly than the reduction in basal ChBF and the choroidal vasodilation that can be elicited via natural (light) or electrical activation of the central neural input to CG choroidal neurons. The prominent age-related decline in parasympathetic control of ChBF early in the pigeon life span could contribute to the age-related retinal decline observed in pigeons.
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Affiliation(s)
- M E C Fitzgerald
- Department of Anatomy & Neurobiology, University of Tennessee, 855 Monroe, Memphis TN 38163, USA.
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Weale RA. A Note on Age-Related Biomarkers. J Gerontol A Biol Sci Med Sci 2005; 60:35-8. [PMID: 15741280 DOI: 10.1093/gerona/60.1.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Forty-eight randomly selected age-related human biological functions were analyzed in order to establish whether or not their (linear) regressions were modified by age-related standard errors. Possible reasons for this are advanced. Statistically significant multiple regressions were obtained in 25%, and 21% of the functions yielded statistically significant changes in the correlations between data and age when partial correlation coefficients were calculated. The conclusion is that age-related data need to be subjected to the above tests in order to minimize confounding factors.
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Affiliation(s)
- Robert A Weale
- Institute of Gerontology, King's College London (University of London), Waterloo Bridge Wing, Waterloo Rd., London SE1 9NN, UK.
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Collignon-Robe NJ, Feke GT, Rizzo JF. Optic nerve head circulation in nonarteritic anterior ischemic optic neuropathy and optic neuritis. Ophthalmology 2004; 111:1663-72. [PMID: 15350320 DOI: 10.1016/j.ophtha.2004.05.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2003] [Accepted: 05/07/2004] [Indexed: 10/26/2022] Open
Abstract
PURPOSE To quantify optic nerve head circulatory abnormalities in patients with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) or optic neuritis (ON), and to assess the potential of such measurements to differentiate NAION from ON. DESIGN Prospective, cross-sectional, observational study. PARTICIPANTS Thirty consecutive patients with unilateral NAION, 22 consecutive patients with unilateral ON, and 50 healthy control subjects. METHODS All subjects underwent a complete neuro-ophthalmologic evaluation. The widths of Doppler-broadened frequency spectra, which are directly proportional to the speed of blood cells flowing through the capillaries of the optic nerve head, were measured at multiple sites in both eyes of each subject. The variation of Doppler broadening (DB) with age was determined in the control subjects. Doppler broadening values in the patients were compared between similar sites in affected and contralateral eyes, and between both affected and contralateral eyes and the age-adjusted values determined in the control subjects. MAIN OUTCOME MEASURES The differences in DB between (1) the affected and contralateral eyes of the patients, (2) the patients and the control subjects, and (3) the patients with NAION and those with ON. RESULTS In NAION, DB was decreased at both temporal (-20.2% and -18.5%) and nasal (-12.8% and -12.4%) sites of the nerve head in affected eyes compared with contralateral eyes or eyes of control subjects. In ON, DB was also decreased at temporal sites (-11.3% and -9.2%) in affected eyes compared with contralateral or control eyes. At nasal sites, there were no significant differences in DB in affected eyes of ON patients compared with contralateral or control eyes. The DB decreases were significantly greater in NAION patients than in ON patients. CONCLUSIONS Optic nerve head circulatory abnormalities are present in patients with NAION or ON. This is the first demonstration of such abnormalities in ON, a finding consistent with the recent attention given to the phenomenon of axonal loss in this disease. Although there are differences in the circulatory abnormalities between the 2 diseases that provide insights into the pathophysiological mechanisms at play, they are not large enough to enable the clinician to distinguish between ON and NAION in an individual patient.
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Affiliation(s)
- Nathalie J Collignon-Robe
- Massachusetts Eye and Ear Infirmary and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
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Abstract
The human visual system undergoes continuous anatomical, physiological and functional changes throughout the life span. There is also continuous change in the spectral distribution and intensity of light reaching the retina from infancy through senescence, primarily due to changes in the absorption of short-wave light by the lens. Despite these changes in the retinal stimulus and the signals leaving the retina for perceptual analysis, color appearance is relatively stable during aging as measured by broadband reflective or self-luminous samples, the wavelengths of unique blue and yellow, and the achromatic locus. Measures of ocular media density for younger and older observers show, indeed, that color appearance is independent of ocular media density. This may be explained by a renormalization process that was demonstrated by measuring the chromaticity of the achromatic point before and after cataract surgery. There was a shift following cataract surgery (removal of a brunescent lens) that was initially toward yellow in color space, but over the course of months, drifted back in the direction of the achromatic point before surgery. The spatial characteristics of color mechanisms were quantified for younger and older observers in terms of chromatic perceptive fields and the chromatic contrast sensitivity functions. Younger and older observers differed with small spots or with chromatic spatial gratings near threshold, but there were no significant differences with larger spots or suprathreshold spatial gratings.
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Affiliation(s)
- John S. Werner
- Department of Ophthalmology and Section of Neurobiology, Physiology & Behavior, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, U.S.A
| | - Peter B. Delahunt
- Department of Ophthalmology and Section of Neurobiology, Physiology & Behavior, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, U.S.A
| | - Joseph L. Hardy
- Department of Ophthalmology and Section of Neurobiology, Physiology & Behavior, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, U.S.A
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Tzekov RT, Gerth C, Werner JS. Senescence of human multifocal electroretinogram components: a localized approach. Graefes Arch Clin Exp Ophthalmol 2004; 242:549-60. [PMID: 15085352 PMCID: PMC2581767 DOI: 10.1007/s00417-004-0892-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2003] [Revised: 02/06/2004] [Accepted: 02/09/2004] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Previous studies have shown significant age-related changes in the first-order kernel of multifocal ERG (mfERG) responses. All of these reports were based upon ring averages across the retinal field. This study was carried out to determine age-related changes in the localized response and localized variability in the mfERG parameters: N1P1 amplitude, scalar product and implicit time of P1. METHODS MfERG recordings from 70 normal phakic subjects (ages 9-80 years) were analyzed with VERIS 4.8. Scalar product values (for each hexagon based on ring average templates) were obtained and analyzed for age-related changes. Statistical measures such as coefficient of variation (CV) and parameters of a linear regression model were applied. Point-by-point comparisons were made across hemifields. RESULTS Each localized response showed a significant aging effect either in scalar product or in N1P1 amplitude. The average decline of the response was approximately 5% per decade, varying from 3.3% (peripherally) to 7.5% (perifoveally). The decline was significantly higher for the superior than for the inferior retina for amplitude parameters, corresponding to larger increases in P1 implicit time. The relative rate of change with age was similar for the nasal and the temporal retina. The average CV for all subjects at all locations was 29.4% (+/-4.1%). CONCLUSIONS The localized approach revealed patterns of age-related change that were not apparent in the ring averages. Information about changes in discrete retinal areas with age should make the mfERG more useful in quantitatively monitoring progression of retinal disease.
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Affiliation(s)
- Radouil T Tzekov
- Department of Ophthalmology, University of California-Davis, Suite 2400, 4860 Y Street, Sacramento, CA 95817, USA
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Toker E, Yenice O, Akpinar I, Aribal E, Kazokoglu H. The influence of sex hormones on ocular blood flow in women. ACTA ACUST UNITED AC 2004; 81:617-24. [PMID: 14641265 DOI: 10.1111/j.1395-3907.2003.00160.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To investigate the influence of sex hormones on ocular haemodynamics, blood flow velocities in the ophthalmic and central retinal arteries and serum levels of sex hormones were measured in pre- and postmenopausal women. METHODS Colour Doppler imaging (CDI) was used to determine the flow velocities (peak systolic velocity [PSV] and end-diastolic velocity [EDV]) and the resistive index (RI) in the ophthalmic and central retinal arteries in 22 premenopausal and 32 postmenopausal women, who had never received hormone replacement therapy. Serum levels were measured for oestradiol, free testosterone and follicle-stimulating hormone. The CDI parameters were compared between the two groups and the influence of serum levels of oestradiol and testosterone on blood flow velocities and the resistive indices were analysed. RESULTS After correcting for age and mean arterial blood pressure, an analysis of covariance disclosed a significantly lower EDV (p=0.02) and a significantly higher RI (p=0.01) in the central retinal artery of postmenopausal women compared with premenopausal women. Partial correlation analysis, controlling for age, revealed significant correlations between the CDI parameters and serum levels of oestradiol and testosterone. For premenopausal women, PSV (r=0.58, p=0.04) and EDV (r=0.73, p=0.006) in the ophthalmic artery correlated positively with serum oestradiol levels. The RI in the central retinal artery decreased with increasing oestradiol levels in both groups (premenopausal r= -0.40, p=0.04; postmenopausal r= -0.32, p=0.05). Peak systolic velocity in the central retinal artery correlated negatively (r= -0.49, p=0.04), whereas the RI correlated positively (r=0.53, p=0.02) with testosterone levels in the premenopausal group. Postmenopausal women with higher testosterone levels had lower EDV (r= -0.53, p=0.007) in the central retinal artery and higher RI in both vessels (ophthalmic artery r=0.48, p=0.01; central retinal artery r=0.61, p=0.002). CONCLUSION Our data provide evidence of a relationship between serum sex hormone levels and blood flow velocities and resistive indices in retrobulbar arteries. Oestradiol appears to have beneficial effects on ocular haemodynamics, whereas testosterone may act as an antagonistic to the effects of oestrogen.
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Affiliation(s)
- Ebru Toker
- Department of Ophthalmology, Marmara University Medical School, Istanbul, Turkey.
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Kimura I, Shinoda K, Tanino T, Ohtake Y, Mashima Y, Oguchi Y. Scanning laser Doppler flowmeter study of retinal blood flow in macular area of healthy volunteers. Br J Ophthalmol 2004; 87:1469-73. [PMID: 14660455 PMCID: PMC1920574 DOI: 10.1136/bjo.87.12.1469] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To compare the interocular and intraocular differences of capillary perfusion, and the intraocular regional differences of retinal blood flow in the macular area of healthy volunteers. METHODS Tissue blood flow in the macula was examined in both eyes of 20 healthy volunteers with the Heidelberg retinal flowmeter. Blood flow measurements were made in a 10 degrees x 2.5 degrees area superior and inferior to the macula. The mean blood flow (MBF) was calculated by an automatic full field perfusion image analyser program. The MBF in the right and left eyes and in the superior and inferior macular areas of the same eye were compared. RESULTS The ratios of the MBF in the right eye to the left eye in the macular areas were 1.00, and 1.03, respectively. The ratio of the MBF in the superior macular area to the inferior area was 1.01 for the right eyes and 1.04 for the left eyes. CONCLUSIONS Because no significant differences were found in the MBF between the two eyes and between the superior and inferior macular areas in the same eye, interocular (for example, affected eye versus fellow eye) and intraocular (superior versus inferior macular areas) comparisons of MBF can be made to determine if changes in retinal perfusion have occurred.
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Affiliation(s)
- I Kimura
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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Isobe H, Yamamoto K, Cyong JC. Effects of hachimi-jio-gan (ba-wei-di-huang-wan) on blood flow in the human central retinal artery. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2004; 31:425-35. [PMID: 12943173 DOI: 10.1142/s0192415x03001181] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hachimi-jio-gan (HJG), a Chinese herbal formula, and a placebo were given to 12 healthy adults, and the changes in blood flow in the central retinal artery were observed with the latest ultrasonic diagnosis device before and after administration. After administration of HJG, the systolic flow velocity, diastolic flow velocity and mean flow velocity in the central retinal artery showed significant increases. No change was observed in vascular resistance. The subjects deemed suitable for use of HJG showed remarkable increases in blood flow. No changes in blood flow velocities and vascular resistance were observed after administration of the placebo. HJG is frequently used in the aged, often with eye diseases such as cataract. It has been reported that a decrease of blood flow in the central retinal artery becomes more marked in proportion to the progress of various eye diseases. As increases in blood flow were obvious in the cases that were treated with HJG, it is suggested that increases in blood flow in the central retinal artery due to HJG give direct evidence supporting the positive effects of HJG on eye diseases.
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Affiliation(s)
- Hideyuki Isobe
- Department of Bioregulatory Function, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
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Tadayoni R, Paques M, Gaudric A, Vicaut E. Erythrocyte and leukocyte dynamics in the retinal capillaries of diabetic mice. Exp Eye Res 2003; 77:497-504. [PMID: 12957148 DOI: 10.1016/s0014-4835(03)00155-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The purpose of this study was to analyse the dynamics of red blood cells (RBC) and white blood cells (WBC) in the retinal capillaries of C57BL/KS db/db mice, a genetic model of type 2 diabetes, and control mice, at different ages. Modified epifluorescence microscopy was used to analyse the capillary velocity of FITC-labeled RBC and rhodamine-labeled WBC in the retina. C57BL/KS db/db diabetic mice were compared to heterozygous non-diabetic mice at ages 8 and 18 weeks (n=6 in each group). At 8 weeks, when hyperglycemia begins in db/db mice, no significant difference was found between average RBC and WBC velocity of the 2 groups. At 18 weeks, RBC velocity was significantly higher in diabetic mice compared to controls (1.21+/-0.29 versus 1.08+/-0.28 mm sec(-1) p=0.0003). No significant difference was found between WBC velocities (0.87+/-0.3 versus 0.85+/-0.3 mm sec(-1)) even when normalized by RBC velocity values. Temporal and spatial coefficients of variation were significantly higher for WBC than RBC velocities (p<0.0001) but were not significantly different in diabetic and control mice. Direct measurement of RBC velocity with this new method showed that it was higher in the retinal capillaries of diabetic than control mice after 10-12 weeks of hyperglycemia, but not at the onset of hyperglycemia. This suggests that enhanced RBC velocity is not an immediate effect of hyperglycemia but a consequence of persistent hyperglycemia. The above results are in line with the hypothesis that microvascular flow increases in diabetes, as one of the first microvascular alterations. In contrast, WBC velocity was not different in diabetic and control mice.
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Affiliation(s)
- Ramin Tadayoni
- Laboratoire d'Etude de la Microcirculation, Hôpital Fernand Widal, 200 rue du Faubourg Saint-Denis, 75010 Paris, France
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Yao Y, Ma Z, Zhao J. Luminal characteristics of central retinal vessels in the anterior optic nerve of the young human. Retina 2002; 22:449-54. [PMID: 12172112 DOI: 10.1097/00006982-200208000-00009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To study the luminal characteristics of the central retinal vessels of young humans where the vessels pass through the anterior optic nerve. METHODS Serial sections of nine central retinal arteries (CRAs) and 13 central retinal veins (CRVs) from 12 eyes of 12 young donors (aged 20-29 years) without known ocular disease or anatomic malformation were examined by image analysis to determine their luminal dimensional differences right at, anterior to, and posterior to the lamina cribrosa. RESULTS The average values of the mean area of the CRAs in the prelaminar, laminar, and retrolaminar portions were 16.5 x 10(3) microm2, 17.2 x 10(3) microm2, and 15.2 x 10(3) microm2, and mean perimetric lengths were 541 microm, 528 microm, and 492 microm, respectively. Differences were detected in perimetric length and theoretical luminal area between the laminar and retrolaminar portions, but not the prelaminar and laminar portions. The average values of the mean area of the CRVs in the prelaminar, laminar, and retrolaminar portions were 24.6 x 10(3) microm2, 13.3 x 10(3) microm2, and 7.8 x 10(3) microm2, and mean perimetric lengths were 689 microm, 544 microm, and 411 microm, respectively. There were marked differences between the prelaminar and laminar values and between the laminar and retrolaminar values in terms of the perimetric lengths and theoretical luminal areas. CONCLUSIONS The results suggest that the resistance of blood flow in CRAs decreases when the blood enters the eye. The gradual constriction of CRVs from the prelaminar to the retrolaminar portion may act as a throttle mechanism in controlling the outflow of the blood and in maintaining the patency of the retinal venules and capillaries.
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Affiliation(s)
- Yi Yao
- Department of Ophthalmology, PLA General Hospital, Beijing, People's Republic of China
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Hosking SL, Embleton SJ, Cunliffe IA. Application of a local search strategy improves the detection of blood flow deficits in the neuroretinal rim of glaucoma patients using scanning laser Doppler flowmetry. Br J Ophthalmol 2001; 85:1298-302. [PMID: 11673292 PMCID: PMC1723767 DOI: 10.1136/bjo.85.11.1298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIM Blood flow measures acquired using the scanning laser Doppler flowmeter (SLDF) are known to be highly susceptible to spatial and temporal variations of physiological origin. The purpose of this study was to evaluate a local search strategy intended to overcome these intrinsic variations, thereby improving the detection of blood flow defects resulting from glaucoma. METHODS The sample consisted of one eye of each of 15 glaucoma patients (aged 69.1 (SD 6.6) years) and 15 normal subjects (aged 65.2 (13.7) years). Three 10 degree images of the superior temporal retina and three images of the superior temporal rim were acquired using the Heidelberg retina flowmeter (HRF). Standard analysis was performed using a 10 x 10 pixel frame. For the search strategy the same frame was located within a 15 x 15 pixel window and manually repositioned in order to identify the highest and lowest local values of blood flow. Student's paired t test was used to identify differences between groups for the two methods (p<0.05). RESULTS The standard strategy revealed no significant differences in blood flow measures between the subjects at either the retina or neuroretinal rim. With the search strategy there was also no difference in blood flow measures at the retina. At the neuroretinal rim, the search strategy demonstrated that the highest measured blood flow, volume, and velocity values were significantly lower for the glaucoma patients (p = 0.002, 0.02, and 0.002 respectively) while comparison of the lowest flow values showed that glaucoma patients had lower blood flow and velocity only (p = 0.023 and 0.021 respectively). CONCLUSIONS Glaucoma patients exhibit reduced ocular blood flow at the neuroretinal rim, which seems to affect high velocity flow more profoundly than low velocity flow. When analysing perfusion images a local search strategy is recommend to identify the highest local blood flow values in order to optimise the ability to differentiate between subject groups.
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Affiliation(s)
- S L Hosking
- Neurosciences Research Institute, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
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Kergoat H, Kergoat MJ, Justino L, Lovasik JV. Age-related topographical changes in the normal human optic nerve head measured by scanning laser tomography. Optom Vis Sci 2001; 78:431-5. [PMID: 11444633 DOI: 10.1097/00006324-200106000-00016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE This study was designed to investigate the effects of advanced aging on the optic nerve head (ONH) structure and retinal nerve fiber layer (RNFL) thickness in the eldest segment of our population. METHODS Twenty-seven healthy elderly subjects between 75 and 88 years of age (average, 80.1 +/- 0.83 years) and 30 healthy younger subjects between 20 and 32 years of age (average, 23.1 +/- 0.50 years) were recruited for a cross-sectional comparison between ONH morphology and RNFL thickness as measured by scanning laser tomography. The ONH disc, cup, and rim areas; cup-to-disc ratio; and the mean thickness of the RNFL were quantified. RESULTS The cup and disc areas as well as the cup-to-disc area ratio increased with age, whereas the RNFL thickness decreased during the course of normal senescence. CONCLUSIONS Any diagnoses of ocular pathology in the elderly must differentiate the effects of normal aging on the ONH topography and RNFL thickness. To that effect, the present study provides a clinical profile of ocular structures that extend into the oldest geriatric age group.
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Affiliation(s)
- H Kergoat
- School of Optometry, University of Montreal, Québec, Canada.
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Tomita G, Niwa Y, Shinohara H, Hayashi N, Yamamoto T, Kitazawa Y. Changes in optic nerve head blood flow and retrobular hemodynamics following calcium-channel blocker treatment of normal-tension glaucoma. Int Ophthalmol 2001; 23:3-10. [PMID: 11008892 DOI: 10.1023/a:1006423919238] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Because calcium channel blockers reduce vascular resistance, they may have a clinical application in the treatment of normal-tension glaucoma (NTG). This study investigates changes in both the optic disc blood flow and the hemodynamics of retrobulbar vessels in NTG patients after the systemic administration of a calcium channel blocker. METHODS Twelve eyes of 12 NTG patients (mean age 57.6 +/- 15.3 years) were examined before and after a 4-week treatment with 2 mg b.i.d. oral nilvadipine, an L-typc calcium channel blocker. By scanning laser-Doppler flowmetry (SLDF), we obtained the velocity, flow, and volume from within a 10 x 10 pixel window placed on the temporal rim region of the optic disc perfusion map. By ultrasound color Doppler imaging (CDI), we measured the peak systolic velocity (PSV) and the end diastolic velocity (EDV) of the ophthalmic artery (OA), central retinal artery (CRA), nasal posterior ciliary artery (NPCA), and temporal posterior ciliary artery (TPCA). We then calculated a resistance index (RI) for each vessel. RESULTS After treatment, the flow and velocity of the optic disc blood flow significantly increased (P < 0.05). Nilvadipine also significantly reduced RIs of the CRA, NPCA, and TPCA (P < 0.05), and increased both the PSV of the NPCA and the EDVs of the CRA, NPCA, and TPCA. The percent change in velocity correlated significantly with the percent changes of the CRA RI and NPCA RI. CONCLUSIONS Oral nilvadipine appears to reduce orbital vascular resistance, which consequently increases the optic disc blood flow.
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Affiliation(s)
- G Tomita
- Department of Ophthalmology, Gifu University School of Medicine, Gifu-ken, Japan.
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