Accommodation-related Changes In The High-order Aberrations As A Function Of Myopia

Purpose:Ocular wavefront aberrations are influenced by many factors, and varied with accommodation. Purpose of this experiment is to investigate the changes in high-order aberrations (HOAs) during accommodation as the function of refractive error.Methods:This study enrolled65subjects (age range:18to28years old), and the spherical equivalent (SE) ranged from-0.50D to-8.75D without abnormal ocular finding. All the participants were divided into three groups depending on SE:low myopia group (Group1, n=23, SE:-0.50to-3.00D, mean±SD:-2.352±0.868D), moderate myopia group (Group2, n=23, SE:-3.25to-6.00D, mean±SD:-4.813±0.900D) and high myopia group (Group3, n=19, SE:-6.25to-9.00D, mean±SD:-7.342±0.895D). Accommodative stimulus were in the range of0to5D, with an increment of1D. The wavefront aberrations over natural pupil size were measured using Hartmann-Shack aberrometer. The changes in aberrations during accommodation for different groups and different pupil conditions (natural and fixed3.0mm pupil) were compared.Results:1. Under relaxed condition, there were no significant difference in pupil diameter, root-mean-square (RMS) of HOAs (HORMS), spherical aberration (SA) and coma among the three groups (P=0.056to0.973). HORMS were found positively correlated with SA and coma (r=0.504and0.625, respectively,P<0.001). For fixed pupil size, SE did not correlate with HORMS (r=-0.005, P=0.966) and coma (r=-0.036, P=0.780), but negatively correlated with SA (r=-0.230, P=0.035).2. During accommodation, HORMS for natural pupil size decreased in Group2(r=-0.210,P=0.029), but increased in Group3(r=0.205, P=0.046). Moreover, HORMS for fixed pupil size increased (r=0.232to0.407, P<0.05) and SA decreased (r=-0.203to-0.405, P<0.05) in the three groups. Coma increased with accommodation in Groups2and3(r=0.216and0.289, respectively, P<0.05).3. The pupil size decreased during accommodation (r=-0.324to-0.437, respectively, P<0.001). Under relaxed condition, the pupil size was negatively correlated with HORMS over fixed pupil size (r=-0.254, P=0.022).Conclusions:The ocular high-order aberrations mainly originated from spherical aberration and coma. The total high-order aberration, spherical aberration and coma changed during accommodation, and the trend of alternation increased with the refractive error. The pupil size reduced with accommodation and may play a role in controlling retinal image quality.