Abstract
Purpose: :
To evaluate the effect of change in higher order aberrations (HOAs) with accommodation on visual function in normal and post–LASIK eyes.
Methods: :
Twenty–three eyes of 12 patients who underwent LASIK (mean age, 30.3 yrs; mean refraction, –0.61 D) and 20 eyes of 10 normal patients (mean age, 30.5 yrs; mean refraction, –0.53 D) were included. The mean correction was –3.81 D in the LASIK group. Distance and near (33 cm) visual acuity (VA) with and without correction and distance and near (33 cm) contrast sensitivity (CS) with correction were measured. HOAs were measured with accommodative stimulus of 0, 1, 3, and 5 D using remodeled ARK–10000 (Nidek, Aichi, Japan). The root mean square of total HOAs, coma–like aberrations, trefoil–like aberrations, and spherical aberration were evaluated at each measurement. Pupil size was measured using an open–view–type pupillometer (FP–10000, TMI, Tokyo, Japan).
Results: :
There were no significant differences in distance and near VA between the groups. The near CS was comparable to or higher than the distance CS in both groups. Coma–like aberrations did not change significantly with accommodation in both groups. There was a significant difference between 0 D and 5 D in total HOAs and trefoil–like aberrations, although the absolute value was small in each. Spherical aberrations decreased significantly in both groups, but the absolute value was small in each. The pupil size in near fixation differed significantly from that in distance fixation in both groups.
Conclusions: :
The amount of change in HOAs with accommodation is too small to affect visual performance, suggesting that no major problem in near visual function occurs if the target correction is determined based on wavefront aberrations measured in distance fixation before wavefront–guided LASIK.
Keywords: refractive surgery: LASIK • refractive surgery: optical quality • contrast sensitivity