The Refractive Changes and Long-Term (3 Years) Results of Radial Keratotomy Performed at High Altitude

Abstract

Purpose: To evaluate the development of regression or progression following radial keratotomy (RK) performed at high altitude (1,720 meters) at long-term follow-up (3 years). Methods: Thirty-nine eyes of 21 myopia patients (between -3.25 D and -11.00 D) whose ages were 19-32 years were included in the study. The RK procedures were performed in standard Russian style. Results: The average spherical equivalent cycloplegic refractions were -5.49 D ± 2.08 (SD) preoperatively, -1.64 ± 1.59 D in the short-term (3.41 ± 1.46 months) and -1.40 ± 1.71 D in the long-term (30.72 ± 4.36 months) follow-up period. There was no statistically significant difference between these values at the short- and long-term follow-up measurements (t = -1.57, P = .12). Conclusions: The refractive changes following RK performed at high altitude occur through a combination of both the direct effect of reduced barometric pressure and the edematous corneal expansion because of hypoxia. An ophthalmologist performing RK surgery at high altitude must consider the long-lasting therapeutic effects of high altitude surgery compared to surgery at sea level. Copyright © 2001 Japanese Ophthalmological Society.