PMID: 8600422Mar 1, 1996Paper

Effects of simulated high altitude on patients who have had radial keratotomy

Ophthalmology
J D NgT H Mader

Abstract

Previous studies documented diurnal myopic shifts in patients who have had radial keratotomy (RK). Recently, hyperopic shifts in these patients exposed to high altitude have been reported. A direct mechanical effect of reduced barometric pressure on surgically altered corneas has been theorized to cause this hyperopic shift. Another hypothesis implicates the effect of hypobaric hypoxia on the RK incisions. The authors examined the effect of a 6-hour exposure to decreased barometric pressure on 14 normal and 18 RK corneas. Cycloplegic refraction, keratometry, corneal pachymetry, and tonometry were performed on seven control subjects and nine patients who have had RK. Measurements were obtained over 8 hours at sea level on day 1 of the study. Measurements were repeated on day 2 which included a 6-hour exposure to 12,000 feet simulated altitude in a hypobaric chamber. Results were compared between subjects and control subjects to determine the effect of a 6-hour exposure to decreased barometric pressure. There was no statistically significant difference in refraction or keratometry readings between control subjects and subjects who have had RK. Central corneal thickness decreased in the afternoon in RK eyes compared with control e...Continue Reading

References

Feb 1, 1987·Ophthalmology·P Wyzinski, L W O'Dell
Oct 1, 1970·Archives of Ophthalmology·K A Polse, R B Mandell
Oct 1, 1982·The British Journal of Ophthalmology·J P Bergmanson, L W Chu

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Citations

Sep 1, 2005·Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht Von Graefes Archiv Für Klinische Und Experimentelle Ophthalmologie·Mitrofanis PavlidisSolon Thanos
Nov 30, 2000·Ophthalmology·L J White, T H Mader
Mar 21, 2012·High Altitude Medicine & Biology·Thomas H Mader, Lawrence J White
Apr 7, 2007·Cornea·Daniel S MorrisBaljean Dhillon
Dec 28, 1999·Journal of Cataract and Refractive Surgery·N T PetersM B Strauss
Sep 19, 2000·Journal of Cataract and Refractive Surgery·T Yaşar, S Simşek
Sep 17, 2002·Journal of Cataract and Refractive Surgery·Enoch T HuangMark I Langdorf
Feb 1, 2002·Journal of Cataract and Refractive Surgery·Michael A McMannThomas H Mader
Apr 10, 2008·Current Eye Research·Atilla BayerMehmet Zeki Bayraktar
Oct 17, 2020·Vestnik oftalmologii·S E AvetisovK S Avetisov

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