Abstract
Abstract: :
Purpose: To compare the distribution and magnitude of higher order aberrations (HOAs) in Army helicopter flight applicants treated with LASIK or PRK (LASEK) to controls (standard applicants). To determine correlations of quality of optics with performance in flight training. Methods: HOAs were measured in 100 LASIK, 35 PRK and 40 controls using the COAS (Wavefront Sciences, Inc) and analyzed for a 5 mm pupil. Flight performance was graded by Instructor Pilots during 3 main phases (Primary, Instrument and Night) of Initial Entry Rotary Wing Training (IERW). Results: HO RMS for both refractive surgery groups were significantly greater than controls. Specific HOAs (SA, coma and trefoil) were not significantly different between LASIK and PRK subjects, but were significantly greater than controls, with sign shifts in horizontal coma and trefoil. HOAs correlated to differences in low contrast acuity (R2=0.12), but only weakly to flight performance (R2=0.05). Conclusions: Although vision is a key sense in flight, flight performance is multifactorial involving vision, cognition and coordination. HOAs after refractive surgery help to explain only a small percentage of performance. A higher correlation is anticipated for more visually–demanding flight scenerios (e.g. combat, urban or unaided night operations).
Keywords: refractive surgery: comparative studies • visual acuity