Acute Mountain Sickness and Retinal Evaluation by Optical Coherence Tomography

Ascaso, Francisco J.; Nerín, Maria Antonia; Villén, Laura; Morandeira, J. R.; Cristobal, Ja

doi:10.5301/ejo.5000091

Cited by 14 publications

(14 citation statements)

References 32 publications

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“…4500 m) have provided evidence for increased thickness of retinal nerve fibers and dilated, tortuous retinal vessels, it seems plausible to assume this as a contributing factor for the relative increase in TRT in the outer ETDRS subfields [13], [19], [30], [33]. One previous OCT study on retinal changes associated with high altitude exposure and acute mountain sickness showed no significant alteration in any of the ETDRS subfields [13]. However, subjects in this study were examined at an altitude of 247 m two weeks before and after returning from the expeditions in the Himalayas.…”

Section: Discussionmentioning

confidence: 98%

“…Detailed quantitative analyses of macular changes at high altitude might be difficult to perform due to unique logistic challenges. Some studies circumvented this problem by recording changes several days after the exposure to altitude [13] – [16] . However, measurements acquired any time after descent may not reflect the changes during acute exposure to high altitude related hypoxia.…”

Section: Introductionmentioning

confidence: 99%

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Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude

Fischer¹,

Willmann²,

Schatz³

et al. 2012

PLoS ONE

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BackgroundThis study aimed to quantify structural and functional changes at the macula during acute exposure to high altitude and to assess their structure/function relationship. This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study.Methodology/Principal FindingsSpectral domain optical coherence tomography and microperimetry were used to quantify changes of central retinal structure and function in 14 healthy subjects during acute exposure to high altitude (4559 m). High-resolution volume scans and fundus-controlled microperimetry of the posterior pole were performed in addition to best-corrected visual acuity (BCVA) measurements and assessment of acute mountain sickness. Analysis of measurements at altitude vs. baseline revealed increased total retinal thickness (TRT) in all four outer ETDRS grid subfields during acute altitude exposure (TRTouter = 2.80±1.00 μm; mean change±95%CI). This change was inverted towards the inner four subfields (TRTinner = −1.89±0.97 μm) with significant reduction of TRT in the fovea (TRTfoveal = −6.62±0.90 μm) at altitude. BCVA revealed no significant difference compared to baseline (0.06±0.08 logMAR). Microperimetry showed stable mean sensitivity in all but the foveal subfield (MSfoveal = −1.12±0.68 dB). At baseline recordings before and >2 weeks after high altitude exposure, all subjects showed equal levels with no sign of persisting structural or functional sequels.Conclusions/SignificanceDuring acute exposure to high altitude central retinal thickness is subject to minor, yet statistically significant changes. These alterations describe a function of eccentricity with an increase in regions with relatively higher retinal nerve fiber content and vascular arcades. However, these changes did not correlate with measures of central retinal function or acute mountain sickness. For the first time a quantitative approach has been used to assess these changes during acute, non-acclimatized high altitude exposure.

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Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude

Fischer¹,

Willmann²,

Schatz³

et al. 2012

PLoS ONE

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“…Fischer et al 8 adopted OCT and microdetermination to quantify changes in central retinal structure and function of 14 healthy subjects during rapid ascent to a high-altitude area (4559 m), and results found an increase of total retinal thickness. Ascaso et al 9 employed OCT to conduct complete ophthalmologic examinations for 12 healthy male mountaineers after four high-altitude expeditions in the Himalayas, and results indicated that average peripapillary RNFL thickness as well as the RNFL thickness of superior and temporal quadrants got a notable increase and that VIRA was much higher than that at baseline altitude. In this study, OCT was also used to determine the fine structure of retina such as thickness of the RNFL and GCL in the macula and the RNFL in the optic disc.…”

Section: Discussionmentioning

confidence: 99%

Retinal changes following rapid ascent to a high-altitude environment

Tian

Jia

et al. 2017

Eye

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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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“…RNFL thickness was measured using the Stratus Optical Coherence Tomography (OCT) (Carl Zeiss Meditec, UK). OCT has been used extensively in many previous studies to assess RNFL thickness in vivo in various ophthalmic and neurologic diseases [17-19], as well as neurodegenerative disorders with frequent cognitive changes like schizophrenia [20], obstructive sleep apnoea syndrome [21], or acute mountain sickness [22], and has been widely tested in the elderly. Thinning of the RNFL has been noted with ageing, as demonstrated not only by OCT in different populations [23-27], but also by red-free photography [28], scanning laser polarimetry [29] and nerve fibre counts of post mortem human tissue [30].…”

Section: Introductionmentioning

confidence: 99%

Retinal nerve fiber layer thickness and cognitive ability in older people: the Lothian Birth Cohort 1936 study

et al. 2013

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BackgroundThis study aims to examine the relationship between the retinal nerve fiber layer (RNFL) thickness as measured by optical coherence tomography (OCT) and lifetime cognitive change in healthy older people.MethodsIn a narrow-age sample population from the Lothian Birth Cohort 1936 who were all aged approximately 72 years when tested, participants underwent RNFL measurements using OCT. General linear modeling was used to calculate the effect of RNFL thickness on three domains; general cognitive ability (g-factor), general processing speed (g-speed) and general memory ability (g-memory) using age at time of assessment and gender as co-variates.ResultsOf 105 participants, 96 completed OCT scans that were of suitable quality for assessment were analyzed. Using age and gender as covariates, we found only one significant association, between the inferior area RNFL thickness and g-speed (p = 0.049, η2 = 0.045). Interestingly, when we included age 11 IQ as a covariate in addition to age and gender, there were several statistically significant associations (p = 0.029 to 0.048, η2 = 0.00 to 0.059) in a negative direction; decreasing scores on measures of g-factor and g-speed were associated with increasing RNFL thickness (r = −0.229 to −0.243, p < 0.05). No significant associations were found between RNFL thickness and g-memory ability. When we considered the number of years of education as a covariate, we found no significant associations between the RNFL thickness and cognitive scores.ConclusionsIn a community dwelling cohort of healthy older people, increased RNFL thickness appeared to be associated with lower general processing speed and lower general cognitive ability when age 11 IQ scores were included as a covariate.

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Acute Mountain Sickness and Retinal Evaluation by Optical Coherence Tomography

Abstract: In climbers with AMS, OCT was able to detect subtle increases in the peripapillary RNFL thickness and in some ONH measurements, even in absence of HACE and papilledema. These changes might be a sensitive parameter in physiologic acclimatization and in the pathogenesis of AMS.

Cited by 14 publications

References 32 publications

Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude

Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude

Retinal changes following rapid ascent to a high-altitude environment

Retinal nerve fiber layer thickness and cognitive ability in older people: the Lothian Birth Cohort 1936 study

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