High Altitude Retinal Hemorrhages–An Update

Bosch, Martina M.; Barthelmes, Daniel; Landau, Klara

doi:10.1089/ham.2012.1077

Cited by 23 publications

(8 citation statements)

References 33 publications

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“…It has long been known that high altitude leads in some subjects to a swollen ONH, dilated retinal veins, and retinal hemorrhages [ 41 ]. These changes have been assumed to be secondary to an increase of intracranial pressure due to cerebral edema [ 42 ]. However, high altitudes lead to a mild but global hypoxia and therefore to an increased ET-1 level in the circulating blood [ 17 , 43 ] and an RVP increase [ 4 ].…”

Section: Reviewmentioning

confidence: 99%

Retinal venous pressure: the role of endothelin

Konieczka

2015

EPMA Journal

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The retinal venous pressure (RVP) can be measured non-invasively. While RVP is equal to or slightly above intraocular pressure (IOP) in healthy people, it is often markedly increased in patients with eye or systemic diseases. Beside a mechanical obstruction, the main cause of such an elevation is a local dysregulation of a retinal vein, particularly a constriction induced by endothelin-1 (ET-1). A local increase of ET-1 can result from a high plasma level, as ET-1 can diffuse from the fenestrated capillaries of the choroid into the optic nerve head (ONH), bypassing the blood retinal barrier. A local increase can also result from increased local production either by a sick neighboring artery or retinal tissue. Generally, the main factors increasing ET-1 are inflammations and hypoxia, either locally or in a remote organ. RVP is known to be increased in patients with glaucoma, retinal vein occlusion (RVO), diabetic retinopathy, high mountain disease, and primary vascular dysregulation (PVD). PVD is the major vascular component of Flammer syndrome (FS). An increase of RVP decreases perfusion pressure, which heightens the risk for hypoxia. An increase of RVP also elevates transmural pressure, which in turn heightens the risk for retinal edema. In patients with RVO, a high level of RVP may not only be a consequence but also a potential cause of the occlusion; therefore, it risks causing a vicious circle. Narrow retinal arteries and particularly dilated retinal veins are known risk indicators for future cardiovascular events. As the major cause for such a retinal venous dilatation is an increased RVP, RVP may likely turn out to be an even stronger predictor.

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Section: Reviewmentioning

confidence: 99%

Retinal venous pressure: the role of endothelin

Konieczka

2015

EPMA Journal

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“…In earlier studies, high-altitude retinopathies were observed in experienced climbers, and the manifestations included retinal vascular engorgement, tortuosity, dilation, and hemorrhage. 17 , 19 , 51 , 52 However, no prominent retinal pathological structural changes were observed during the high-altitude exposure. On the one hand, this might be associated with a stronger retinal tolerance ability to high-altitude exposure in mice.…”

Section: Discussionmentioning

confidence: 92%

Proteomic and Morphological Profiling of Mice Ocular Tissue During High-altitude Acclimatization Process: An Animal Study at Lhasa

Hou¹,

Zheng²,

Wen³

et al. 2022

JIR

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Purpose High-altitude environment mainly with hypobaric hypoxia could induce pathological alterations in ocular tissue. Previous studies have mostly focused on sporadic case reports and simulated high-altitude hypoxia experiments. This aim of this study was to explore the proteomic and morphological changes of ocular tissue in mice at real altitude environment. Methods In this study, mice were flown from Chengdu (elevation: 500 m) to Lhasa (elevation: 3600 m). After exposure for 1day, 3, 6, 10, 20, 30, and 40days, the mice were euthanatized to obtain blood and ocular tissue. Serological tests, ocular pathological examinations, integral ocular proteomics analysis, and Western blot were conducted. Results We focused on acute phase (1–3 days) and chronic phase (>30 days) during high-altitude acclimatization. Serum interleukin-1 was increased at 3 days, while superoxide dismutase, interleukin-6, and tumor necrosis factor-α showed no statistical changes. H&E staining demonstrated that the cornea was edematous at 3 days and exhibited slower proliferation at 30 days. The choroid showed a consistently significant thickening, while there existed no noticeable changes in retinal thickness. Overall, 4073 proteins were identified, among which 71 and 119 proteins were detected to have significant difference at 3 days and 40 days when compared with the control group. Functional enrichment analysis found the differentiated proteins at 3 days exposure functionally related with response to radiation, dephosphorylation, negative regulation of cell adhesion, and erythrocyte homeostasis. Moreover, the differential profiles of the proteins at 40 days exposure exhibited changes of regulation of complement activation, regulation of protein activation cascade, regulation of humoral immune response, second-messenger-mediated signaling, regulation of leukocyte activation, and cellular iron homeostasis. Interestingly, we found the ocular proteins with lactylation modification were increased along high-altitude adaptation. Conclusion This is the first work reporting the ocular proteomic and morphological changes at real high-altitude environment. We expect it would deep the understanding of ocular response during altitude acclimatization.

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“…Klara Landau, a neuro-ophthalmologist and specialist in strabismus with an international background was appointed in 2005 and chaired the remarkable celebration of the clinic's 150th anniversary in 2012 [63]. Klara Landau also contributed significantly to researching the influence of high altitude on the function of the eyes with her Zurich team, fitting for a country in the Alps [64][65][66][67].…”

Section: In Zurich a New Department Is Created -And Finally A Woman mentioning

confidence: 99%

Contributions to Progress in Ophthalmology from Switzerland: From the 16th to the 21st Century

Gerste¹

2020

Ophthalmologica

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There are numerous contributions to the development of ophthalmology from Switzerland, a country that holds a very special place in the history of medicine from the age of Paracelsus and Vesal to the current time. This review gives an overview over these contributions and the pioneers, among them Johann Friedrich Horner, Hans Goldmann, Jules Gonin, and Walter Rudolf Hess, one of only two ophthalmologists ever awarded the Nobel Prize for Medicine. A leading role in this evolution of modern ophthalmology has been played by physicians from Basel, home of Switzerland’s oldest university.

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High Altitude Retinal Hemorrhages–An Update

Cited by 23 publications

References 33 publications

Retinal venous pressure: the role of endothelin

Retinal venous pressure: the role of endothelin

Proteomic and Morphological Profiling of Mice Ocular Tissue During High-altitude Acclimatization Process: An Animal Study at Lhasa

Contributions to Progress in Ophthalmology from Switzerland: From the 16th to the 21st Century

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