OBJECTIVE: Refractive changes at high altitude that occur after radial keratotomy (RK) may be caused by hypoxia or hypobaria. DESIGN: A prospective study was performed to evaluate the effects of hypoxia on RK and non-RK corneas. PARTICIPANTS: There were 20 RK and 20 control eyes. INTERVENTION: These eyes were subjected to ocular surface hypoxia using an air-tight goggle system at sea level for 2 hours. MAIN OUTCOME MEASURES: Keratometry, cycloplegic refraction, and pachymetry were evaluated using repeated measures analysis of variance. RESULTS: A significant hyperopic shift (P < 0.0001) and corneal flattening (P < 0.0013) occurred in all subjects with RK compared with those of control subjects. Corneal thickening occurred symmetrically in both groups. CONCLUSIONS: These results suggest that refractive changes in subjects with RK occur at high altitude as a direct result of corneal hypoxia.
OBJECTIVE: Refractive changes at high altitude that occur after radial keratotomy (RK) may be caused by hypoxia or hypobaria. DESIGN: A prospective study was performed to evaluate the effects of hypoxia on RK and non-RK corneas. PARTICIPANTS: There were 20 RK and 20 control eyes. INTERVENTION: These eyes were subjected to ocular surface hypoxia using an air-tight goggle system at sea level for 2 hours. MAIN OUTCOME MEASURES: Keratometry, cycloplegic refraction, and pachymetry were evaluated using repeated measures analysis of variance. RESULTS: A significant hyperopic shift (P < 0.0001) and corneal flattening (P < 0.0013) occurred in all subjects with RK compared with those of control subjects. Corneal thickening occurred symmetrically in both groups. CONCLUSIONS: These results suggest that refractive changes in subjects with RK occur at high altitude as a direct result of corneal hypoxia.
Authors: M P Van Akin; O M Lantz; A M Fellows; Christine Toutain-Kidd; Michael Zegans; J C Buckey; A P Anderson Journal: Front Physiol Date: 2022-08-31 Impact factor: 4.755