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Han C, Zheng XX, Zhang WF. High altitude retinopathy: An overview and new insights. Travel Med Infect Dis 2024; 58:102689. [PMID: 38295966 DOI: 10.1016/j.tmaid.2024.102689] [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: 09/01/2023] [Revised: 12/30/2023] [Accepted: 01/15/2024] [Indexed: 02/04/2024]
Abstract
High altitude retinopathy (HAR) is a common ocular disorder that occurs on ascent to high altitude. There are many clinical symptoms, retinal vascular dilatation, retinal edema and hemorrhage are common. These usually do not or slightly affect vision; rarely, severe cases develop serious or permanent vision loss. At present, the research progress of HAR mainly focuses on hemodynamic changes, blood-retinal barrier damage, oxidative stress and inflammatory response. Although the related studies on HAR are limited, it shows that HAR still belongs to hypoxia, and hypobaric hypoxia plays an aggravating role in promoting the development of the disease. Various studies have demonstrated the correlation of HAR with acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), so a deeper understanding of HAR is important. The slow ascent rates and ascent altitude are the key to preventing any altitude sickness. Research on traditional chinese medicine (TCM) and western medicine has been gradually carried out. Further exploration of the pathogenesis and prevention strategies of HAR will provide better guidance for doctors and high-altitude travelers.
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Affiliation(s)
- Cong Han
- Department of Ophthalmology, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, 730000, Gansu, PR China.
| | - Xing-Xing Zheng
- Department of Ophthalmology, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, 730000, Gansu, PR China.
| | - Wen-Fang Zhang
- Department of Ophthalmology, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, 730000, Gansu, PR China.
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2
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Zhao Y, Zou H, Fan W, Liu Y, Chen X, Huang Y, Yuan R. Patterns of Structural Changes in the Fundus Measured by Optical Coherence Tomography Angiography as Potential Markers of Acute Mountain Sickness. Transl Vis Sci Technol 2023; 12:15. [PMID: 38088829 PMCID: PMC10720760 DOI: 10.1167/tvst.12.12.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/03/2023] [Indexed: 12/17/2023] Open
Abstract
Purpose To use optical coherence tomography angiography (OCTA) to assess the pattern of changes in retinal and choroidal blood flow and structure in healthy volunteers who quickly went from sea level to a plateau and to determine the parameters associated with acute mountain sickness (AMS). Methods Forty-five individuals (89 eyes) were examined by OCTA and filled out the AMS questionnaire. One baseline examination was performed on the plain, followed by examinations at days 1, 3, and 5 after entering the plateau. Parameters were self-controlled to explore patterns of change, analyzed for correlation with AMS score, and modeled as a nomogram of AMS risk. Results On the plateau compared to the plain, vascular morphology showed dilated superficial macular retinal vessels and constricted deeper layers with increased vessel length density and fractal dimension; vessel density increased in all retinal strata and decreased in the choroidal macrovascular layer; and thickness increased except for a decrease in mean retinal thickness in the central macular sulcus. The rate of increase in retinal nerve fiber layer (RNFL) thickness in the inner and outer macular rings correlated with AMS score (r = -0.211). The nomogram showed moderate accuracy (AUC = 0.672) and consistency (C-index = 0.659) in assessing AMS risk. Conclusions In high-altitude hypoxia, retinal vessels dilate and distort, resulting in increased blood flow density and thickness. Increased RNFL thickness in the paracentral macula may be a marker of low AMS risk. Translational Relevance The changes in the retinal structure of the fundus can be used to assess the risk of developing AMS.
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Affiliation(s)
- Yuancheng Zhao
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Huan Zou
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Wei Fan
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Yuqi Liu
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Xiaofan Chen
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Yanming Huang
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Rongdi Yuan
- Department of Ophthalmology, Second Affiliated Hospital of Army Medical University, Chongqing, China
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Lu CW, Huang ST, Cheng SJ, Lin CT, Hsu YC, Yao CT, Dong F, Hung CM, Kuo HC. Genomic architecture underlying morphological and physiological adaptation to high elevation in a songbird. Mol Ecol 2023; 32:2234-2251. [PMID: 36748940 DOI: 10.1111/mec.16875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/17/2023] [Accepted: 02/03/2023] [Indexed: 02/08/2023]
Abstract
Organisms often acquire physiological and morphological modifications to conquer ecological challenges when colonizing new environments which lead to their adaptive evolution. However, deciphering the genomic mechanism of ecological adaptation is difficult because ecological environments are often too complex for straightforward interpretation. Thus, we examined the adaptation of a widespread songbird-the rufous-capped babbler (Cyanoderma ruficeps)-to a relatively simple system: distinct environments across elevational gradients on the mountainous island of Taiwan. We focused on the genomic sequences of 43 birds from five populations to show that the Taiwan group split from its sister group in mainland China around 1-2 million years ago (Ma) and colonized the montane habitats of Taiwan at least twice around 0.03-0.22 Ma. The montane and lowland Taiwan populations diverged with gene flow between them, suggesting strong selection associated with different elevations. We found that the montane babblers had smaller beaks than the lowland ones, consistent with Allen's rule, and identified candidate genes-COL9A1 and SOX11-underlying the beak size changes. We also found that altitudinally divergent mutations were mostly located in noncoding regions and tended to accumulate in chromosomal inversions and autosomes. The altitudinally divergent mutations might regulate genes related to haematopoietic, metabolic, immune, auditory and vision functions, as well as cerebrum morphology and plumage development. The results reveal the genomic bases of morphological and physiological adaptation in this species to the low temperature, hypoxia and high UV light environment at high elevation. These findings improve our understanding of how ecological adaptation drives population divergence from the perspective of genomic architecture.
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Affiliation(s)
- Chia-Wei Lu
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Shih-Ting Huang
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Shun-Jen Cheng
- Department of Natural Resources and Environmental Studies, National Dong Hwa University, Hualien, Taiwan
| | - Chen-Tau Lin
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Yu-Cheng Hsu
- Department of Natural Resources and Environmental Studies, National Dong Hwa University, Hualien, Taiwan
| | - Cheng-Te Yao
- Division of Zoology, Endemic Species Research Institute, Nantou, Taiwan
| | - Feng Dong
- Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Chih-Ming Hung
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Hao-Chih Kuo
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
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4
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Ma J, Niu H, Han C, Qu Y. Quantify retinal structure in high-altitude residents with and without high altitude polycythemia. BMC Ophthalmol 2023; 23:6. [PMID: 36597056 PMCID: PMC9811807 DOI: 10.1186/s12886-022-02674-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 11/07/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND To assess retinal structural parameters in high-altitude (HA) residents with and without high altitude polycythemia (HAPC) and to elucidate the relationship between retinal structural parameters and hemoglobin (HGB). METHODS This cross-sectional study included 55 HAPC patients and 52 healthy HA residents. Retinal structural parameters included retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) parameters and retinal vessel diameter. RNFL thickness were acquired from spectral domain optical coherence tomography (SD-OCT) built-in software. ONH parameters including neuroretina rim height, cup area, disc area and vertical cup/disc ratio were obtained by OCT built-in software and ImageJ software. Retinal vessel measurements including central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE) and AVR (artery/vein ratio) were calculated by revised formulas for summarizing retinal vessel diameters. All parameters were compared between HAPC group versus healthy HA group. The associations between retinal parameters and HGB were assessed by Pearson correlation analyses. RESULTS In comparison of HAPC group versus healthy HA group, RNFL thickness was thicker in the nasal quadrant of the optic disc in HAPC group (74.82 ± 14.4 VS. 66.06 ± 13.71 μm, P = 0.002). Bigger disc area and bigger cup area were also observed in HAPC group (all P < 0.05). Meanwhile, the value of CRVE was higher in HAPC group which suggested that retinal veins dilated significantly in HAPC patients (P < 0.001), however, CRAE and AVR were comparable between groups. Pearson analyses revealed that HGB was positive correlated with CRVE in HAPC group (r = 0.469, P = 0.003). CONCLUSIONS long-term HA exposure secondary HAPC could result in thickened RNFL, enlarged ONH and dilated retinal veins. Moreover, increased blood viscosity caused by HGB should be responsible for dilated veins, but not for thickened RNFL and enlarged ONH. This study deepens the understanding of the impact of HA environment on retina.
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Affiliation(s)
- Jinlan Ma
- Department of Ophthalmology, Affiliated Hospital of Qinghai University, Xining, China.,Department of Health Care, Qilu Hospital of Shandong University, No. 107, Wenhuaxi Road, Jinan, 250012, China
| | - Haoyu Niu
- Department of Ophthalmology, Affiliated Hospital of Qinghai University, Xining, China
| | - Changjing Han
- Department of Ophthalmology, Affiliated Hospital of Qinghai University, Xining, China
| | - Yi Qu
- Department of Health Care, Qilu Hospital of Shandong University, No. 107, Wenhuaxi Road, Jinan, 250012, China.
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Baker J, Safarzadeh MA, Incognito AV, Jendzjowsky NG, Foster GE, Bird JD, Raj SR, Day TA, Rickards CA, Zubieta-DeUrioste N, Alim U, Wilson RJA. Functional optical coherence tomography at altitude: retinal microvascular perfusion and retinal thickness at 3,800 meters. J Appl Physiol (1985) 2022; 133:534-545. [PMID: 35771223 DOI: 10.1152/japplphysiol.00132.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cerebral hypoxia is a serious consequence of several cardiorespiratory illnesses. Measuring the retinal microvasculature at high altitude provides a surrogate for cerebral microvasculature, offering potential insight into cerebral hypoxia in critical illness. Additionally, while sex-specific differences in cardiovascular diseases are strongly supported, few have focused on differences in ocular blood flow. We evaluated the retinal microvasculature in males (n=11) and females (n=7) using functional optical coherence tomography at baseline (1,130m) (Day 0), following rapid ascent (Day 2) and prolonged exposure (Day 9) to high altitude (3,800m). Retinal vascular perfusion density (rVPD; an index of total blood supply), retinal thickness (RT; reflecting vascular and neural tissue volume) and arterial blood were acquired. As a group, rVPD increased on Day 2 vs. Day 0 (p<0.001) and was inversely related to PaO2 (R2=0.45; p=0.006). By Day 9, rVPD recovered to baseline, but was significantly lower in males vs. females (p=0.007). RT was not different on Day 2 vs. Day 0 (p>0.99) but was reduced by Day 9 relative to Day 0 and Day 2 (p<0.001). RT changes relative to Day 0 were inversely related to changes in PaO2 on Day 2 (R2=0.6; p=0.001) and Day 9 (R2=0.4; p=0.02). RT did not differ between sexes. These data suggest differential time course and regulation of the retina during rapid ascent and prolonged exposure to high altitude and are the first to demonstrate sex-specific differences in rVPD at high altitude. The ability to assess intact microvasculature contiguous with the brain has widespread research and clinical applications.
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Affiliation(s)
- Jacquie Baker
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Mohammad Amin Safarzadeh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Anthony V Incognito
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Nicholas G Jendzjowsky
- Division of Respiratory and Critical Care Physiology and Medicine, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States
| | - Glen Edward Foster
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Jordan D Bird
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Satish R Raj
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Caroline A Rickards
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Natalia Zubieta-DeUrioste
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,High Altitude Pulmonary and Pathology Institute (HAPPI - IPPA), La Paz, Bolivia
| | - Usman Alim
- Department of Computer Science, University of Calgary, Calgary, Alberta, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
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Yin X, Li Y, Ma Y, Xie Y, Wang K, Sun D, Liu X, Hao M, Liang M, Zhang S, Guo Y, Jin L, Wang N, Wang J. Thickened Retinal Nerve Fiber Layers Associated With High-Altitude Headache. Front Physiol 2022; 13:864222. [PMID: 35600299 PMCID: PMC9114875 DOI: 10.3389/fphys.2022.864222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/01/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose: This study aimed to quantify the different quadrants of the optic nerve head (ONH) and macular parameters and their changes during exposure to high altitude, and to assess their correlation with high-altitude headache (HAH).Methods: Spectral-domain optical coherence tomography (OCT) was used to quantify changes in the retinal structure in 109 healthy subjects during acute exposure to high altitude (3,700 m). Self-reported symptoms of HAH and acute mountain sickness AMS were assessed using Lake Louise Score (LLS), alongside measurements of physiological parameters (oxygen saturation [SpO2], heart rate [HR], hemoglobin level [Hb], and red blood cell [RBC] count). Measurements were taken before and after exposure to the high-altitude environment. The correlations of these parameters and changes at ONH were examined.Results: With the exposure to high altitude, the incidence of AMS was 44.0% and the frequency of HAH was 67.0% (54.1% mild, 12.9% moderate-severe). As for systemic parameters measured at high altitude, the participants exhibited significantly lower SpO2, higher resting HR, higher Hb, and a higher RBC (all p < 0.05). Key stereometric parameters used to describe ONH [superior, inferior, nasal, temporal, and mean retinal nerve fiber layer (RNFL) thickness] and macula (macular thickness) increased at high altitude compared with baseline. Most parameters of ONH changed, especially superior, inferior, and mean RNFL thickness (p < 0.05). There was a significant correlation between the ratios of RNFL at ONH and HAH [mean thickness (r = 0.246, p = 0.01); inferior (r = 0.216, p = 0.02); nasal (r = 0.193, p = 0.04)]. No associations between parameters of ONH and AMS or LLS were observed.Conclusion: The high-altitude environment can increase RNFL thickness at ONH. Furthermore, we found that the ratios of mean thickness, inferior area, and nasal area correlated positively with HAH, which provides new insights for understanding of the underlying pathological mechanisms of high-altitude retinopathy (HAR).
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Affiliation(s)
- Xianhong Yin
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Yi Li
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
- Institute for Six-Sector Economy, Fudan University, Shanghai, China
- International Human Phenome Institutes, Shanghai, China
| | - Yanyun Ma
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
- Institute for Six-Sector Economy, Fudan University, Shanghai, China
| | - Yuan Xie
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kun Wang
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Dayan Sun
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Xiaoyu Liu
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Meng Hao
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Meng Liang
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Shixuan Zhang
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Yuan Guo
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
| | - Li Jin
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
- International Human Phenome Institutes, Shanghai, China
- Research Institute of Data Sciences, Fudan University, Shanghai, China
- Research Unit of Dissecting the Population Genetics and Developing New Technologies for Treatment and Prevention of Skin Phenotypes and Dermatological Diseases, Chinese Academy of Medical Sciences (2019RU058), Shanghai, China
- *Correspondence: Jiucun Wang, ; Ningli Wang, ; Li Jin,
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- *Correspondence: Jiucun Wang, ; Ningli Wang, ; Li Jin,
| | - Jiucun Wang
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, and Human Phenome Institute, Fudan University, Shanghai, China
- Research Unit of Dissecting the Population Genetics and Developing New Technologies for Treatment and Prevention of Skin Phenotypes and Dermatological Diseases, Chinese Academy of Medical Sciences (2019RU058), Shanghai, China
- *Correspondence: Jiucun Wang, ; Ningli Wang, ; Li Jin,
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Feng X, Wang L, Wang H, Qi H, Zhang J, Wang Y. Branch retinal artery occlusion secondary to high-altitude exposure and diabetic retinopathy: a case report. BMC Ophthalmol 2020; 20:281. [PMID: 32652960 PMCID: PMC7353733 DOI: 10.1186/s12886-020-01563-1] [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] [Received: 04/01/2020] [Accepted: 07/08/2020] [Indexed: 11/25/2022] Open
Abstract
Background To report a case of branch retinal artery occlusion (BRAO) secondary to high-altitude exposure and diabetic retinopathy (DR), and to characterize the retinal changes before and after hyperbaric oxygen (HBO) treatment. Case presentation We present a case of a 42-year-old man with DR who travelled to Tibet (in China, 3800 m/12467 ft. above mean sea level). The day after the end of his journey, the patient presented with acute, painless visual loss and visual field loss in his left eye. He was then diagnosed with BRAO, which is an acute blockage of blood flow. After HBO treatment, visual acuity and visual field were improved. Conclusions High-altitude exposure and DR may be considered as relevant risk factors for BRAO. The ophthalmologist should be aware that the BRAO might be a rare presenting sign of high-altitude retinopathy (HAR), particularly in patients with DR. HBO treatment can be considered as a choice for ophthalmologists on treatment against BRAO.
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Affiliation(s)
- Xue Feng
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, NO.95 Yong'an Road, Xicheng District, Beijing, 100050, China.,Department of Ophthalmology, Beijing Moslem People's Hospital, Beijing, China
| | - Luping Wang
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, NO.95 Yong'an Road, Xicheng District, Beijing, 100050, China
| | - Haiwei Wang
- Department of Ophthalmology, Fuxing Hospital, Capital Medical University, Beijing, China
| | - Hong Qi
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
| | - Jianqiang Zhang
- Department of Ophthalmology, Beijing Moslem People's Hospital, Beijing, China
| | - Yanling Wang
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, NO.95 Yong'an Road, Xicheng District, Beijing, 100050, China.
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Krusche T, Limmer M, Jendrusch G, Platen P. Influence of Natural Hypobaric Hypoxic Conditions on Dynamic Visual Performance. High Alt Med Biol 2020; 21:1-11. [PMID: 31746645 DOI: 10.1089/ham.2019.0033] [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] [Indexed: 01/28/2023] Open
Abstract
Background: Both dynamic and static visual performances are essential for safety and motoric performance at altitude. There is a lack of information regarding alterations in dynamic visual performance (DVP) in oxygen-reduced environments. The purpose of this study was to analyze DVP in natural hypoxic conditions in a group of young, healthy hikers. Methods: DVP in four parafoveal subfields was analyzed using the computer-assisted Düsseldorf Test for Dynamic Vision. Measurements were performed twice at altitudes above 3500 m during an 8-day alpine hike. Results: On day 5 (3647 m), no changes in DVP were detected. On day 6 (4554 m), however, we found a significant reduction in DVP in the superior parafoveal retinal subfield, partly representing the lower visual field. The observed changes did not correlate with oxygen saturation, hematocrit, or cardiovascular parameters. We found no interrelation between symptoms of acute mountain sickness and DVP at altitude. Conclusions: Our data suggest that hiking at altitudes above 4500 m results in lower DVP in the visual field of healthy young people. The alteration might affect motor performance and coordination, increasing the risk of accidents.
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Affiliation(s)
- Till Krusche
- Department of Sports Medicine and Sports Nutrition, Faculty of Sport Science, Ruhr-Universität Bochum, Bochum, Germany
| | - Mirjam Limmer
- Department of Sports Medicine and Sports Nutrition, Faculty of Sport Science, Ruhr-Universität Bochum, Bochum, Germany.,Institute of Outdoor Sports and Environmental Science, German Sport University Cologne, Cologne, Germany
| | - Gernot Jendrusch
- Department of Sports Medicine and Sports Nutrition, Faculty of Sport Science, Ruhr-Universität Bochum, Bochum, Germany
| | - Petra Platen
- Department of Sports Medicine and Sports Nutrition, Faculty of Sport Science, Ruhr-Universität Bochum, Bochum, Germany
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Wu Y, Qiong Da CR, Liu J, Yan X. Intraocular pressure and axial length changes during altitude acclimatization from Beijing to Lhasa. PLoS One 2020; 15:e0228267. [PMID: 31995608 PMCID: PMC6988913 DOI: 10.1371/journal.pone.0228267] [Citation(s) in RCA: 4] [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: 07/20/2019] [Accepted: 01/12/2020] [Indexed: 11/29/2022] Open
Abstract
Purpose To investigate changes in intraocular pressure (IOP) and axial length (AL) on the ascent to high altitude from Beijing to Lhasa. Patients and methods Twenty volunteers (17 men, 3 women) who had been sent to work in Lhasa, Tibet for more than 6 months were enrolled. One of their journeys from Beijing to Lhasa was chosen as the time for the examination. IOP, AL, corneal curvature (K), and blood pressure (BP) were measured in Beijing (altitude 43 m) and Lhasa (altitude 3658 m). Their first examination was conducted at least 1 day before arriving in Lhasa and the second examination after they had stayed in Lhasa for 7 days. The data from the highland and lowland examinations were analyzed with a paired-sample T test and Pearson’s correlation coefficient was calculated for the association between IOP and average BP. Results The mean IOP was 12.65±2.34 mmHg in Beijing and 14.85±3.1 mmHg in Lhasa. The mean AL was 24.61±1.50mm in Beijing, and 24.98±1.45 mm in Lhasa. The IOP and AL showed a significant elevation in highland compared with lowland (P<0.05). The mean K was 43.58±2.25 D in Beijing and 43.56±2.21 D in Lhasa and no significant difference was found in this study (P>0.05). A positive correlation between variance of IOP and ACD was found (r = 0.475, P<0.05) and no correlation between IOP and average BP was noted. Conclusions High altitude may lead to a small but significant change in IOP and axial length. However, the shape of the corneal surface was not influenced by the hypobaric and hypoxic conditions.
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Affiliation(s)
- Yuan Wu
- Department of Ophthalmology, Peking University First Hospital, Beijing, China
| | - Ci Ren Qiong Da
- Department of Ophthalmology, Tibet Autonomous Region People’s Hospital, Lhasa, Tibet Autonomous Region, China
| | - Jiang Liu
- Department of Ophthalmology, Tibet Autonomous Region People’s Hospital, Lhasa, Tibet Autonomous Region, China
| | - Xiaoming Yan
- Department of Ophthalmology, Peking University First Hospital, Beijing, China
- * E-mail:
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10
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Krusche T, Jendrusch G, Platen P. Short- and middle-term high-altitude exposure does not affect visual acuity and contrast sensitivity of healthy young people. J Sci Med Sport 2019; 22 Suppl 1:S12-S16. [PMID: 31151876 DOI: 10.1016/j.jsams.2019.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/23/2019] [Accepted: 04/30/2019] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Visual acuity and contrast sensitivity are crucial for optimal performance and safe sport activity. From a practical sport-specific perspective, visual performance is obligatory for orientation and movement control in mountainous areas. The purpose of this study was to analyze the effect of hypobaric hypoxic conditions on visual acuity and contrast sensitivity of short-term and middle-term acclimatized healthy young people. DESIGN This study used a repeated-measure design with ten eye-healthy and physically active students representing different types of sports. METHODS With the help of a computer-based Landolt C and a Sine Wave Contrast test, visual performance was investigated similar before (156 m), during a nine-day high-altitude sojourn (sleeping level: 890-4640 m), and three months later (156 m). All tests were performed under standardized illumination conditions. Additionally, morning blood oxygen saturation, hematocrits, hemoglobin, body mass, and self-reported symptoms of acute mountain sickness criteria were determined. RESULTS Whole blood oxygen saturation declined during altitude exposure. The analysis of central visual performance at altitude showed no effect of hypobaric hypoxia. CONCLUSION Our data suggest that activity in a hypobaric hypoxia condition at moderate to high altitude levels of up to 4600 m does not affect visual acuity and contrast sensitivity of acclimatized healthy young people. However, in contrast to previous studies that outlined acutely impaired central visual performance with respect to hypoxia, we suggest that acclimatization might induce adaptation of visual perception performance and therefore reduce the risk of accidents resulting from partial loss of visual performance at altitude.
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Affiliation(s)
- Till Krusche
- Department of Sports Medicine and Sports Nutrition, Faculty of Sport Science, Ruhr-Universität Bochum, Germany.
| | - Gernot Jendrusch
- Department of Sports Medicine and Sports Nutrition, Faculty of Sport Science, Ruhr-Universität Bochum, Germany
| | - Petra Platen
- Department of Sports Medicine and Sports Nutrition, Faculty of Sport Science, Ruhr-Universität Bochum, Germany
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11
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Tian X, Zhang B, Jia Y, Wang C, Li Q. Retinal changes following rapid ascent to a high-altitude environment. Eye (Lond) 2018; 32:370-374. [PMID: 28912514 PMCID: PMC5811714 DOI: 10.1038/eye.2017.195] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 07/26/2017] [Indexed: 01/26/2023] Open
Abstract
PurposeTo determine what impact rapid ascension to a high-altitude environment has on the retina with the aim of preventing and treating high-altitude oculopathy.Patients and methodsParticipants in the study were members of the Chinese military assigned to the high-altitude environment of the Tibetan plateau. Ninety-one participants were enrolled in the study. Optical coherence tomography was used to measure the thickness of retina-related indicators. Measurements were taken before and after exposure to the high-altitude environment and upon return to the baseline altitude.ResultsFollowing exposure to the high-altitude environment in Tibet, there was a significant increase in retinal nerve fiber layer (RNFL) thickness in the temporal and nasal quadrants of the optic disc, whilst a significant decrease in RNFL thickness in the inferior optic disc was also observed. A significant increase in RNFL thickness in the superior and inferior macula was also evident, along with a significant increase in the ganglion cell layer thickness in the superior macula. Upon return to the baseline altitude, all measurements returned to baseline levels except for the RNFL of the inferior macula, which was significantly thicker. Pathological changes were also documented in the eyes of nine participants upon returning to baseline altitude, including ischemic optic neuropathy, myopia, and cortical amaurosis.ConclusionsThe high-altitude environment can have a negative impact on the health of the retina and may contribute to the incidence of various eye diseases. This study deepens the understanding of what impact a high-altitude environment has on retina and provides reliable data for blindness prevention and treatment.
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Affiliation(s)
- X Tian
- Department of Ophthalmology, the 153rd Central Hospital of PLA, Zhengzhou, China
| | - B Zhang
- Department of Ophthalmology, the 153rd Central Hospital of PLA, Zhengzhou, China
| | - Y Jia
- Department of Ophthalmology, the 153rd Central Hospital of PLA, Zhengzhou, China
| | - C Wang
- Department of Ophthalmology, the 153rd Central Hospital of PLA, Zhengzhou, China
| | - Q Li
- Department of Ophthalmology, the 153rd Central Hospital of PLA, Zhengzhou, China
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12
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Seitz IP, Zhour A, Kohl S, Llavona P, Peter T, Wilhelm B, Zrenner E, Ueffing M, Bartz-Schmidt KU, Fischer MD. Multimodal assessment of choroideremia patients defines pre-treatment characteristics. Graefes Arch Clin Exp Ophthalmol 2015; 253:2143-50. [PMID: 25744334 DOI: 10.1007/s00417-015-2976-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 02/05/2015] [Accepted: 02/18/2015] [Indexed: 10/23/2022] Open
Abstract
PURPOSE Choroideremia (CHM) is a X-chromosomal disorder leading to blindness by progressive degeneration of choroid, retinal pigment epithelium (RPE), and retinal neurons. A current clinical gene therapy trial (NCT01461213) showed promising safety and efficacy data in a carefully selected patient population. The present study was performed to shed light on pre-treatment characteristics of a larger cohort of CHM patients using a high resolution multi-modal approach. METHODS In a retrospective cross-sectional study, data from 58 eyes of 29 patients with clinically confirmed CHM were analysed including best-corrected visual acuity (BCVA), refractive error, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), perimetry, and tonometry. Residual retinal volume, area of residual RPE, and foveal thickness were quantified to further define natural disease progression and assess symmetry. RESULTS We evaluated 98 data points of BCVA [0.34 ± 0.06 (logMAR); mean ± 95 % confidence interval], 80 of IOP (14.6 ± 0.6 mmHg), and 98 of refraction (-2.16 ± 1.08 spherical equivalent). Visual fields (n = 76) demonstrated variable degrees of concentric constriction (54 % <10°, 25 % 10-30°, 21 % >30°). Mean residual RPE area on FAF (n = 64) measured 8.47 ± 1.91 mm(2) (range 0.30-38.5 mm(2)), while mean neuroretinal volume (n = 42) was found to be 1.76 ± 0.12 mm(3). Age at examination was exponentially associated with BCVA, while logarithmic functions best described progressive loss of retinal area and volume. A high degree of left to right symmetry was found in all modalities with structural markers showing the best correlation (r (2) area = 0.83; r (2) volume = 0.75). CONCLUSION Analysis of these widely available clinical data defines the natural disease characteristics of a relevant patient population eligible for gene therapeutic intervention. In the wake of preliminary reports on safety and efficacy of CHM gene therapy (NCT01461213), this multi-modal assessment of a cohort of CHM patients provides important evidence of the natural rate of disease progression and degree of symmetry between eyes.
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Affiliation(s)
- Immanuel P Seitz
- University Eye Hospital, University of Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Ahmad Zhour
- University Eye Hospital, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Pablo Llavona
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Tobias Peter
- STZ Eyetrial, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Barbara Wilhelm
- STZ Eyetrial, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Eberhart Zrenner
- University Eye Hospital, University of Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | - M Dominik Fischer
- University Eye Hospital, University of Tübingen, Tübingen, Germany. .,Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, UK. .,Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK. .,Merton College, University of Oxford, Oxford, OX1 4JD, UK.
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13
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[High altitude retinopathy: report of 3 cases]. J Fr Ophtalmol 2014; 37:629-34. [PMID: 25199490 DOI: 10.1016/j.jfo.2014.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE To report three cases of vision loss occurring at high altitude. OBSERVATIONS Three patients aged 27 to 52 years presented with scotoma and/or visual acuity deficit upon their return from high altitude expeditions above 6000 m. Fundus examination revealed multiple posterior pole hemorrhages, resolving completely by two months. DISCUSSION Exposure to hypobaric hypoxia at high altitude leads to adaptation mechanisms in order to maintain retinal oxygenation. Certain individuals have an inadequate autoregulatory response and develop signs of "high altitude retinopathy" (HAR), including retinal hemorrhages most often, with occasional vitreous hemorrhage, optic nerve head edema and retinal vein occlusion. The pathophysiology of HAR is not well understood. Identified risk factors include altitude above 4000 m, rapid ascent and personal susceptibility. Age and fitness are unrelated. Association with acute mountain sickness, high-altitude pulmonary edema and high-altitude cerebral edema is still controversial. CONCLUSION Retinal hemorrhages occurring after high-altitude hiking are an early manifestation of HAR and are part of high-altitude illness. HAR usually occurs at altitudes above 4000 m, is generally asymptomatic, and spontaneously regresses. A maladaptive autoregulatory response to hypobaric hypoxia appears to be the cause of HAR.
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Update on High Altitude Cerebral Edema Including Recent Work on the Eye. High Alt Med Biol 2014; 15:112-22. [DOI: 10.1089/ham.2013.1142] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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15
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Willmann G, Schatz A, Fischer MD, Schommer K, Zrenner E, Bartz-Schmidt KU, Gekeler F, Gekeler K. Exposure to High Altitude Alters Tear Film Osmolarity and Breakup Time. High Alt Med Biol 2014; 15:203-7. [DOI: 10.1089/ham.2013.1103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Gabriel Willmann
- Katharinenhospital, Department of Ophthalmology, Stuttgart, Germany
- Centre for Ophthalmology University of Tübingen, Germany
| | - Andreas Schatz
- Katharinenhospital, Department of Ophthalmology, Stuttgart, Germany
- Centre for Ophthalmology University of Tübingen, Germany
| | - M. Dominik Fischer
- Centre for Ophthalmology University of Tübingen, Germany
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
| | - Kai Schommer
- Department of Sports Medicine, Medical Clinic, University Hospital Heidelberg, Heidelberg, Germany
| | | | | | - Florian Gekeler
- Katharinenhospital, Department of Ophthalmology, Stuttgart, Germany
- Centre for Ophthalmology University of Tübingen, Germany
| | - Katrin Gekeler
- Katharinenhospital, Department of Ophthalmology, Stuttgart, Germany
- Centre for Ophthalmology University of Tübingen, Germany
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Willmann G, Fischer MD, Schommer K, Bärtsch P, Gekeler F, Schatz A. Missing correlation of retinal vessel diameter with high-altitude headache. Ann Clin Transl Neurol 2013; 1:59-63. [PMID: 25356382 PMCID: PMC4207505 DOI: 10.1002/acn3.18] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/12/2013] [Accepted: 10/14/2013] [Indexed: 01/20/2023] Open
Abstract
The most common altitude-related symptom, high-altitude headache (HAH), has recently been suggested to originate from restricted cerebral venous drainage in the presence of increased inflow caused by hypoxia. In support of this novel hypothesis, retinal venous distension was shown to correlate with the degree of HAH. We quantified for the first time retinal vessel diameter changes at 4559 m using infrared fundus images obtained from a state of the art Spectralis™ HRA+OCT with a semiautomatic VesselMap 1® software. High-altitude exposure resulted in altered arterial and venous diameter changes at high altitude, however, independent of headache burden.
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Affiliation(s)
- Gabriel Willmann
- Centre for Ophthalmology, University of Tübingen Tübingen, Germany
| | - M Dominik Fischer
- Centre for Ophthalmology, University of Tübingen Tübingen, Germany ; Nuffield Laboratory of Ophthalmology, University of Oxford Oxford, United Kingdom
| | - Kai Schommer
- Department of Sports Medicine, Medical Clinic, University Hospital Heidelberg Heidelberg, Germany
| | - Peter Bärtsch
- Department of Sports Medicine, Medical Clinic, University Hospital Heidelberg Heidelberg, Germany
| | - Florian Gekeler
- Centre for Ophthalmology, University of Tübingen Tübingen, Germany ; Department of Ophthalmology, Katharinenhospital Stuttgart, Germany
| | - Andreas Schatz
- Centre for Ophthalmology, University of Tübingen Tübingen, Germany
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Schatz A, Willmann G, Fischer MD, Schommer K, Messias A, Zrenner E, Bartz-Schmidt KU, Gekeler F. Electroretinographic assessment of retinal function at high altitude. J Appl Physiol (1985) 2013; 115:365-72. [PMID: 23722709 DOI: 10.1152/japplphysiol.00245.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although hypoxia plays a key role in the pathophysiology of many common and well studied retinal diseases, little is known about the effects of high-altitude hypoxia on retinal function. The aim of the present study was to assess retinal function during exposure to high-altitude hypoxia using electroretinography (ERG). This work is related to the Tübingen High Altitude Ophthalmology (THAO) study. Electroretinography was performed in 14 subjects in Tübingen, Germany (341 m) and at high altitude at La Capanna Regina Margherita, Italy (4,559 m) using an extended protocol to assess functional integrity of various retinal layers. To place findings in the context of acute mountain sickness, correlations between ERG measurements and oxygen saturation, heart rate, and scores of acute mountain sickness (AMS) were calculated. At high altitude, the maximum response of the scotopic sensitivity function, the implicit times of the a- and b-wave of the combined rod-cone responses, and the implicit times of the photopic negative responses (PhNR) were significantly altered. A-wave slopes and i-waves were significantly decreased at high altitude. The strongest correlation was found for PhNR and O2 saturation (r = 0.68; P < 0.05). Of all tested correlations, only the photopic b-wave implicit time (10 cd·s/m(2)) was significantly correlated with severity of AMS (r = 0.57; P < 0.05). ERG data show that retinal function of inner, outer, and ganglion cell layer is altered at high-altitude hypoxia. Interestingly, the most affected ERG parameters are related to combined rod-cone responses, which indicate that phototransduction and visual processing, especially under conditions of rod-cone interaction, are primarily affected at high altitude.
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Affiliation(s)
- Andreas Schatz
- Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
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Affiliation(s)
- Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, Zurich Centre for Integrative Human Physiology (ZIHP), and Neuroscience Centre (ZNZ), University of Zurich, Zurich, Switzerland
| | - Gabriel Willmann
- University Eye Hospital and Institute for Ophthalmic Research, Centre for Ophthalmology University of Tübingen, Germany
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Sightings edited by John W. Severinghaus. High Alt Med Biol 2012. [DOI: 10.1089/ham.2012.1334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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