High-altitude ophthalmic changes: An often overlooked entity

Abstract

Letter to the EditorHigh-altitude ophthalmic changes: An often overlooked entityS. KapoorS. KapoorSchaumburg, IllinoisPublished Online:15 Sep 2013https://doi.org/10.1152/japplphysiol.00508.2013MoreSectionsPDF (28 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat to the editor: I read with great interest the recent article by Martinot et al. (4). One aspect of high-altitude exposure that is often overlooked is high-altitude-related ophthalmic changes.For instance, high-altitude exposure may result in “central retinal vein occlusion.” Symptoms consistent with occlusion may appear as early as 2 days after entering higher altitudes (2). On the other hand, retinal vein occlusion has been reported as much as a year after entering higher altitudes (5). Descent to lower altitudes is accompanied by complete resolution of the symptoms in most patients. Retinal hemorrhages may also develop (1). Similarly, vitreous hemorrhages may develop. Chronic exposure to high-altitude hypoxia may result in marked intraretinal angiogenesis. Sudden ascent to higher altitudes may also result in severe hypoxia that may significantly decrease “visual sensitivity,” particularly peripheral sensitivity. For instance, Horng et al. (3) in a recent study reported a significant decline in the “mean visual sensitivity” by 7.2 dB. A slightly decreased negative impact is also seen on central visual sensitivity.Ascent into higher altitudes may also result in the development of glaucoma secondary to altitude-associated accentuation of intraocular pressure. Ascent into higher altitudes is also associated with a resulting increase in the incidence of dry eyes. Incidence rates as high as 50% have been reported (1). A significant association is seen between a Schirmer test score of <5 mm and dry eye symptoms (3). Ascent into higher altitudes also results in accentuation of central corneal thickness. This is secondary to swelling of the corneal stroma secondary to hypoxia-induced endothelial changes (5). This results in a higher incidence of refractive errors in those exposed to high altitudes.It is obvious from the above examples that ascent into high altitude may cause acute as well as chronic ophthalmic changes. Physicians should be aware of these changes, especially in those who regularly have to ascend to high altitudes.DISCLOSURESNo conflicts of interest, financial or otherwise, are declared by the author(s).AUTHOR CONTRIBUTIONSAuthor contributions: S.K. drafted manuscript; S.K. edited and revised manuscript; S.K. approved final version of manuscript.REFERENCES1. Guo B, Lu P, Chen X, Zhang W, Chen R. Prevalence of dry eye disease in Mongolians at high altitude in China: the Henan eye study. Ophthalmic Epidemiol 17: 234–241, 2010.Crossref | ISI | Google Scholar2. Ho TY, Kao WF, Lee SM, Lin PK, Chen JJ, Liu JH. High-altitude retinopathy after climbing Mount Aconcagua in a group of experienced climbers. Retina 31: 1650–1655, 2011.Crossref | ISI | Google Scholar3. Horng CT, Liu CC, Wu DM, Chen JT, Chang CJ, Tsai ML. Visual fields during acute exposure to a simulated altitude of 7620 m. Aviat Space Environ Med 79: 666–669, 2008.Crossref | Google Scholar4. Martinot JB, Mule M, de Bisschop C, Overbeek MJ, Le-Dong NN, Naieje R, Guenard H. Lung membrane conductance and capillary volume derived from the NO and CO transfer in high altitude newcomers. J Appl Physiol 115: 157–166, 2013.Link | ISI | Google Scholar5. Morris DS, Somner JE, Scott KM, McCormick IJ, Aspinall P, Dhillon B. Corneal thickness at high altitude. Cornea 26: 308–311, 2007.Crossref | ISI | Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: S. Kapoor, 75 Kristin Circle, Schaumburg, IL 60195 (e-mail: [email protected]com). Download PDF Previous Back to Top Next FiguresReferencesRelatedInformationCited ByHigh altitude hypoxia: An enigmaCurrent Medicine Research and Practice, Vol. 7, No. 6 More from this issue > Volume 115Issue 6September 2013Pages 949-949 Copyright & PermissionsCopyright © 2013 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.00508.2013PubMed24039258History Published online 15 September 2013 Published in print 15 September 2013 Metrics