Refractive Changes And Corneal Thickness In Healthy Mountaineers At High Altitude : Korjenevskaiai Experience (7105M)

To study variations in refraction and pachymetry during exposure to very high altitudes, and to understand the physiological mechanisms mechanisms responsible for this variation.

monocentric study

12 climbers were followed during the ascent of Korjeneveskaia Pic (7105m) in August 2023 in Tajikistan. Their refraction, corneal thickness oxygen saturation were monitored during the acclimatisation and acclimatisation and ascent phases. the different measurement levels were 706m, 4300m, 5100m, 5600m, 6356m.

10 participants were included. 2 excluded: one for keratoconus and one for severe myopia fitted with a Rigid Gas Permeable Lens. A total of 20 eyes were included. As altitude increases, so does corneal thickness. There is a significant myopic shift between 706m and 6350m. The greatest variations in pachymetry were correlated with the greatest variations in refraction and the greatest variations in oxygen saturation.

These are the highest ophthalmological measurements ever taken.

the myopic shift induced by the hypoxia and acute hypobaria associated with high altitude is explained by the increase in corneal thickness. is explained by the increase in corneal thickness. Corneal edema causes a change in the refractive index of the cornea and its posterior surface posterior surface of the cornea, which explains the myopisation that occurs. This physiological mechanism of apdatation should be compared with that of chronic endothelial decompensation