To compare high order aberrations and analyze corneal posterior surface stability of student pilots who have undergone corneal refractive surgery, and to evaluate the safety and stability of civil aviation student pilots enrolled after lowering the standard of corneal refractive surgery.

Student pilots who underwent candidate physical examination and annual physical examination at the Civil Aviation General Hospital and Civil Aviation Flight University of China Medical Appraisal Center from September 2017 to July 2018 were investigated. Fifty student pilots (100 eyes) who did not undergo corneal refractive surgery and had uncorrected visual acuity≥1.0 were randomly selected as a normal control group, and 67 student pilots (131 eyes) who had undergone corneal refractive surgery were selected as an experimental group, including 29 (56 eyes) undergoing femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), 22 (43 eyes) undergoing laser subepithelial keratomileusis (LASEK), and 16 (32 eyes) undegoing small incision lenticule extraction (SMILE). Uncorrected visual acuity, diopter, contrast sensitivity, tear film break-up time (BUT), and corneal topography were examined. The changes of central anterior chamber depth, eye axis length, and lens thickness before and after surgery were compared. The visual effects and corneal biological parameters of the normal control group, those who had undergone corneal refractive laser surgery, and those who chose different surgical procedures were analyzed.

There was no significant difference between the normal control group and the experimental group in contrast sensitivity or BUT (P>0.05). In the experimental group, the total high-order aberration, spherical aberration, coma, and trefoil aberration significantly increased 6 months after operation (P<0.05). There were significant differences in total high-order aberration, spherical aberration, and coma between groups (P<0.05), but there was no significant difference in trefoil aberration among the three groups. Compared with the LASEK group, the higher-order aberration and spherical aberration differed significantly in the FS-LASIK group (P<0.05), although coma and trefoil aberration were not significantly different (P>0.05). There was no significant difference in corneal posterior surface height or eye axis length between groups, but lens thickness increased significantly (P<0.05) and central anterior chamber depth decreased significantly (P<0.05).

CRS is safe and effective for civil aviation student pilots. FS-LASIK can significantly improve the higher order aberration of student pilots after surgery, which is worthy of application and promotion.