Changes in pupil dynamics at high altitude--an observational study using a handheld pupillometer

High Altitude Medicine & Biology
Mark H WilsonBirmingham Medical Research Expeditionary Society

Abstract

Gross pupil dynamics are used as an indirect measure of brain function. Changes in hypoxia and intracranial pressure are thought to alter pupil responses to light. This study assessed a portable handheld pupil measuring device (pupillometer) in the field investigating the changes in pupil size, speed of reaction, and rate of constriction/dilatation with hypoxia induced by changes in altitude. A correlation between pupil dynamics and acute mountain sickness was sought. Seventeen volunteers were studied following acute exposure to 3450 m and then during a trek to 4770 m in Ladakh, India. The pupillometer was used to record maximum and minimum pupil diameter in response to a standard light source with calculation of latency, constriction and dilatation velocities. Acute mountain sickness (AMS) was recorded using Lake Louise self completed questionnaires both in the morning and afternoon on each day. Acute altitude exposure resulted in a significant reduction of percentage change in pupil size (36.5% to 24.1% p=<0.001), significant delay in pupillary contraction (latency; 0.208 to 0.223 seconds p=0.015) and a significant slowing of the rate of contraction (constriction velocity; -2.77 mm/s to -1.75 mm/s p=0.012). These changes reve...Continue Reading

References

Jan 1, 1989·Intensive Care Medicine·R C HuetN R Coad
Jan 1, 1985·Chronobiology International·R Noiman, A D Korczyn
Aug 1, 1995·Clinical Science·A D WrightA R Bradwell
Jan 1, 1996·British Journal of Anaesthesia·G C FletcherJ H Brown
Jan 15, 2000·Advances in Experimental Medicine and Biology·P H Hackett
Jan 26, 2000·Journal of Cataract and Refractive Surgery·B S Boxer Wachler, R R Krueger
Jan 1, 1950·Pflügers Archiv : European journal of physiology·G K DORING, E SCHAEFERS
Jul 22, 2004·High Altitude Medicine & Biology·Peter H Hackett, Robert C Roach
Oct 12, 2004·Wilderness & Environmental Medicine·Christopher H E ImrayUNKNOWN Brimingham Medical Research Expeditionary Society
Nov 4, 2006·Journal of Cataract and Refractive Surgery·Alan W MichelGrenith Zimmerman
Jan 20, 2007·The Journal of Neuroscience Nursing : Journal of the American Association of Neuroscience Nurses·Kathryn N HultsAnthony Gamst

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Citations

Feb 8, 2014·PloS One·Maximilian SchultheissGabriel Willmann
Sep 12, 2014·High Altitude Medicine & Biology·Raj S DattaniMark H Wilson
Jan 27, 2016·Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht Von Graefes Archiv Für Klinische Und Experimentelle Ophthalmologie·Ce ZhengTin Aung
Sep 12, 2018·Concussion·Patrick M ReganLeonard Temme
Mar 27, 2015·Journal of Neurosurgical Anesthesiology·Laura A HilesEric M Bershad
Jul 28, 2016·High Altitude Medicine & Biology·Katherine HealyWilliam Checkley
Jun 28, 2014·High Altitude Medicine & Biology·Gabriel WillmannPeter Bärtsch
Feb 9, 2010·Current Eye Research·Hasan Basri CakmakSaban Simsek
Jan 24, 2009·Lancet Neurology·Mark H WilsonChris H Imray

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