1
|
Drachmann J, Jeppesen SK, Bek T. Increased Oxygen Saturation in Retinal Venules During Isometric Exercise Is Accompanied With Increased Peripheral Blood Flow in Normal Persons. Invest Ophthalmol Vis Sci 2023; 64:25. [PMID: 37847224 PMCID: PMC10593131 DOI: 10.1167/iovs.64.13.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/29/2023] [Indexed: 10/18/2023] Open
Abstract
Purpose A recent study has shown that an increase in the arterial blood pressure of approximately 10 mm Hg in healthy persons can increase the oxygen saturation in venules from the retinal periphery but not from the macular area. The purpose of the present study was to investigate whether a higher increase in blood pressure has further effects on oxygen saturations and whether this is accompanied with changes in retinal blood flow. Methods In 30 healthy persons, oxygen saturation, diameter, and blood flow were measured in arterioles to and venules from the retinal periphery and the macular area. The experiments were performed before and during an experimental increase in arterial blood pressure of (mean ± SD) 18.3 ± 6.2 mm Hg. Results A higher number of venules than arterioles branching from the temporal vascular arcades to the macular area was balanced by a smaller diameter of the venules. Isometric exercise induced significant contraction of both peripheral and macular arterioles (P < 0.01 for both comparisons) and significant increase in oxygen saturation in both peripheral and macular venules (P < 0.001 for both comparisons). This was accompanied with a significant increase in the blood flow in the peripheral arterioles and venules (P = 0.4 for both comparisons), but not in their macular counterparts (P > 0.06 for both comparisons). Conclusions Increased systemic blood pressure leading to arterial contraction and increased venous oxygen saturation in the retina in normal persons can increase peripheral blood flow without significant effects on macular blood flow. This may contribute to explaining regional differences in the response pattern of retinal vascular disease.
Collapse
Affiliation(s)
- Jacob Drachmann
- Department of Ophthalmology, Aarhus University Hospital, Aarhus N, Aarhus, Denmark
| | | | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, Aarhus N, Aarhus, Denmark
| |
Collapse
|
2
|
Petersen L, Aalkjaer C, Bek T. Vasomotion in Retinal Arterioles Is Modified by Exercise and Flicker Stimulation. Invest Ophthalmol Vis Sci 2022; 63:7. [PMID: 36478197 PMCID: PMC9733652 DOI: 10.1167/iovs.63.13.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Vasomotion is spontaneous oscillations in the diameter of resistance vessels with derived effects on blood flow, and it has been proposed that disturbances in vasomotion may be involved in retinal vascular disease. The purpose of this study was to investigate whether retinal vasomotion shows regional variation and is modified by activated autoregulation. METHODS Video recordings of the diameter of retinal arterioles previously obtained from 55 normal persons were subjected to Fourier analysis to characterize the frequencies and propagation of spontaneous diameter changes in retinal arterioles. The analyses were performed on peripapillary temporal retinal arterioles, on arteriolar branches toward the macular area and the retinal periphery, and were performed during rest, during an increase in the arterial blood pressure induced by isometric exercise, and during increased retinal metabolism induced by flickering light. RESULTS There was no propagation of diameter changes along the studied vascular segments. Isometric exercise constricted the arterioles significantly by (mean ± SD) 1.76% ± 3.56% (P = 0.02) and increased the power of diameter oscillations at very low frequencies (0.1-1.4 c/min). Flicker stimulation dilated the arterioles significantly by (mean ± SD) 5.10% ± 2.91% (P < 0.0001) and reduced the power of diameter oscillations at all but the very low frequencies (P < 0.006 for all comparisons). Flicker-induced dilation and changes in hydraulic conductance were lower in peripheral than in macular arterioles. CONCLUSIONS Retinal vasomotion in normal persons increases during increased arterial blood pressure and decreases during flicker stimulation. The findings may act as a basis for the study of vasomotion in retinal vascular disease.
Collapse
Affiliation(s)
- Line Petersen
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | - Christian Aalkjaer
- Institute for Biomedicin (Physiology), Aarhus University, Aarhus, Denmark
| | - Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| |
Collapse
|
3
|
Bek T, Jeppesen SK. Reduced Oxygen Extraction in the Retinal Periphery When the Arterial Blood Pressure Is Increased by Isometric Exercise in Normal Persons. Invest Ophthalmol Vis Sci 2021; 62:11. [PMID: 33683296 PMCID: PMC7960864 DOI: 10.1167/iovs.62.3.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Purpose Recent evidence suggests that the smaller retinal vessels are significantly involved in the regulation of retinal blood flow and that this regulation may differ among the macular area and the retinal periphery. An alternative to studying blood flow regulation in smaller retinal vessels that are difficult to resolve is to assess the metabolic consequences of changes in the microcirculation using oximetry. Methods In 20 normal persons aged (mean ± SD, range) 30.1 ± 3.8 (24–37) years, the oxygen saturation and diameter of retinal arterioles and venules to the macular area and the retinal periphery were studied before and during an increase in the arterial blood pressure induced by isometric exercise. Results The isometric exercise increased the mean arterial blood pressure by (mean ± SEM) 10.0 ± 1.1 mm Hg but induced no significant changes in the diameter of the arterioles (P = 0.83). The isometric exercise had no significant effect on the oxygen saturation in the arterioles supplying the macular area and the retinal periphery (P > 0.42 for both comparisons). However, there was a significant increase in the oxygen saturation in venules draining the retinal periphery to reduce the oxygen extraction from (mean ± SEM) 36.0% ± 2.3% to 30.6% ± 2.1% (P = 0.002) but no significant change in the preexisting low oxygen extraction in the macular area that changed from (mean ± SEM) 18.2% ± 3.0% to 16.2% ± 1.9% (P = 0.37). Conclusions Minor changes in the arterial blood pressure can induce changes in retinal rheology with significant regional variation. The finding may help explain regional variations in manifestations of retinal vascular disease such as hyperpermeability in the macular area and capillary occlusion in the retinal periphery.
Collapse
Affiliation(s)
- Toke Bek
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | | |
Collapse
|
4
|
Longitudinal stability of retinal blood flow regulation in response to flicker stimulation and systemic hyperoxia in mice assessed with laser speckle flowgraphy. Sci Rep 2020; 10:19796. [PMID: 33188259 PMCID: PMC7666208 DOI: 10.1038/s41598-020-75296-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/08/2020] [Indexed: 11/08/2022] Open
Abstract
This study aimed to evaluate longitudinal changes in retinal blood flow in response to flicker stimulation and systemic hyperoxia in mice using a laser speckle flowgraphy (LSFG-Micro). The retinal blood flow in vascular area surrounding the optic nerve head was measured in 8-week-old male mice every 2 weeks until age 20-week. The coefficient of variation of retinal blood flow under resting condition was analyzed every 2 weeks to validate the consistency of the measurement. On day 1 of the experiment, retinal blood flow was assessed every 20 s for 6 min during and after 3 min flicker light (12 Hz) stimulation; on day 2, retinal blood flow was measured every minute for 20 min during and after 10 min systemic hyperoxia; and on day 3, electroretinography (ERG) was performed. Body weight, systemic blood pressure, and ocular perfusion pressure increased significantly with age, but the resting retinal blood flow and ERG parameters remained unchanged. Retinal blood flow significantly increased with flicker stimulation and decreased with systemic hyperoxia, independent of age. The LSFG-Micro provides consistent and reproducible retinal blood flow measurement in adult mice. Longitudinal assessments of retinal blood flow in response to flicker stimulation and systemic hyperoxia may be useful indexes for noninvasive monitoring of vascular function in retinas.
Collapse
|
5
|
Zhu Z, Liang Y, Yan B, Meng Z, Long K, Zhang Y, Luo J. Clinical effect of conbercept on improving diabetic macular ischemia by OCT angiography. BMC Ophthalmol 2020; 20:382. [PMID: 32977791 PMCID: PMC7519504 DOI: 10.1186/s12886-020-01648-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 09/17/2020] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Varying degrees of macular ischemia generally occur in diabetic retinopathy (DR). This study aims to evaluate the effect of conbercept with 3+ pro re nata (PRN) on macular perfusion status in patients with diabetic macular edema (DME) and quantitatively assess changes in foveal avascular zone (FAZ) areas and capillary density in macular regions by applying optical coherence tomography angiography (OCTA). METHODS Fifty patients were divided into ischemic (n = 31) and non-ischemic (n = 19) groups according to the presence of ischemia on OCTA at baseline. All patients received intravitreal injections of 0.5 mg of conbercept with 3+ PRN principle. The FAZ areas and macular vessel density measured using OCTA were evaluated at baseline, 3 months, and 6 months after treatment in both groups. RESULTS At months 3 and 6, the FAZ area in the ischemic group changed from 0.510 ± 0.171 mm2 to 0.441 ± 0.158 mm2 then to 0.427 ± 0.153 mm2 (p = 0.003, p = 0.296); in the non-ischemic group, it remained stable (p = 0.269, p = 0.926). The superficial vessel density changed from 41.1 ± 4.1 to 42.5% ± 4.7% then to 42.6% ± 4.6% (p = 0.043, p = 0.812), and the deep vessel density changed from 40.7 ± 4.4 to 42.3% ± 3.6% then to 42.3% ± 4.7% (p = 0.072, p = 0.961) in the ischemic group. In the non-ischemic group, the superficial vessel density changed from 44.8 ± 3.2 to 46.0% ± 3.5% then to 45.7% ± 3.3% (p = 0.108, p = 0.666), whereas the deep vessel density changed from 43.6 ± 3.6 to 43.8% ± 3.2% then to 43.5% ± 4.5% (p = 0.882, p = 0.736). Reperfusion in macular nonperfusion areas was observed. CONCLUSION Anti-vascular endothelial growth factor treatment may have a positive effect on macular perfusion status. Furthermore, OCTA had advantages in quantifying and calculating blood flow index in the study of macular perfusion status.
Collapse
Affiliation(s)
- Ziyi Zhu
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Rd, Changsha, Hunan 410011 People’s Republic of China
| | - Youling Liang
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Rd, Changsha, Hunan 410011 People’s Republic of China
| | - Bin Yan
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Rd, Changsha, Hunan 410011 People’s Republic of China
| | - Zhishang Meng
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Rd, Changsha, Hunan 410011 People’s Republic of China
| | - Kejun Long
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Rd, Changsha, Hunan 410011 People’s Republic of China
| | - Yiwei Zhang
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Rd, Changsha, Hunan 410011 People’s Republic of China
| | - Jing Luo
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Rd, Changsha, Hunan 410011 People’s Republic of China
- Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan 410011 People’s Republic of China
| |
Collapse
|
6
|
Yang MC, Zhu XB, Wang YX, Wu SL, Wang Q, Yan YN, Yang X, Yang JY, Chen MX, Lei YH, Wei WB. Influencing factors for peripheral and posterior lesions in mild non-proliferative diabetic retinopathy-the Kailuan Eye Study. Int J Ophthalmol 2020; 13:1467-1476. [PMID: 32953588 DOI: 10.18240/ijo.2020.09.20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/18/2020] [Indexed: 02/08/2023] Open
Abstract
AIM To explore the influencing factors of diabetes type 2 patients with mild non-proliferative diabetic retinopathy (NPDR) in the Kailuan area of Tangshan, Hebei Province, China. METHODS In this non-interventional, retrospective study, 683 patients with type 2 diabetes were included in the Kailuan Diabetic Retinopathy Study involving participants with diabetes in the community-based longitudinal Kailuan Study. Based on the undilated ultra-wide field (200°; UWF) images and partial dilated digital fundus images, the diabetic retinopathy (DR) of the surveyed population was graded. Interobserver agreement was estimated by using Cohen's Kappa statistics. The main outcome indicators included gender, age, weight, height, body mass index, blood pressure, circumferences of neck, waist and hip, current smoking, levels of fasting plasma glucose (FPG), hypersensitive C-reactive protein, creatinine, and cholesterol, etc. According to different lesions' locations of patients with mild NPDR, logistic regression models were used to estimate the odds ratios (ORs) and their 95%CIs of each risk factor. RESULTS The study group of 683 patients included 570 males and 113 females. The mean age of the patients was 62.18±9.41y. Compared with dilated fundus examinations, there was fair agreement with the level of DR identified on UWF images in 63.91% of eyes (k=0.369, 95%CI, 0.00-0.00). Detected by UWF images, there were 98 patients with mild NPDR having peripheral retinal lesions, 35 patients with mild NPDR having posterior lesions, 44 patients with mild NPDR whose lesions were detected both in and out the standard two fields area, and 336 patients with non obvious DR. Parameters that conferred a statistically significant increased risks for mild NPDR with having peripheral retinal lesions were neck circumstance (OR, 1.124; 95%CI, 1.044-1.211), and with posterior lesions were FPG (OR, 1.052; 95%CI, 1.007-1.099). CONCLUSION UWF is an effectiveness means of DR screening. Moreover, it is necessary to evaluate peripheral diabetic retinal lesions which can help to estimate the severity of DR. The phenomenon that nonuniform and inhomogeneous distribution of DR lesions has been found. And the influencing factors in mild NPDR are differing by different lesions' locations.
Collapse
Affiliation(s)
- Mo-Chi Yang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China.,Department of Ophthalmology, General Hospital of Ningxia Medical University, Yinchuan 750004, Ningxia Hui Autonomous Region, China
| | - Xiao-Bo Zhu
- Dongfang Hospital Beijing University of Chinese Medicine, Beijing 100078, China
| | - Ya-Xing Wang
- Beijing Institute of Ophthalmology, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Shou-Ling Wu
- Department of Cardiology, Kailuan General Hospital, Tangshan 063000, Hebei Province, China
| | - Qian Wang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Yan-Ni Yan
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Xuan Yang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Jing-Yan Yang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Meng-Xi Chen
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Ya-Hui Lei
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Wen-Bin Wei
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| |
Collapse
|