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The refractive changes and long-term (3 years) results of radial keratotomy performed at high altitude
T Yaşar1, S Simşek, O F Yilmaz
1Department of Ophthalmology, Faculty of Medicine, The University of Yüzüncü Yil, Van, Turkey.
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.
