Spherical aberration and accommodative insufficiency: Is there a Link?

Abstract

Given the relationship between spherical aberrations and accommodation, the study of these aberrations can be helpful to understand accommodative response in subjects with accommodative dysfunctions. The purpose of this study was to evaluate on-axis and off-axis changes of primary and secondary spherical aberrations, Z(4,0) and Z(6,0), with accommodation in subjects with accommodative insufficiency (AI). Ten subjects with AI and eleven without any accommodative dysfunction (control) participated in this study. On-axis defocus Z(2,0), Z(4,0), and Z(6,0) were obtained in both groups with a Hartmann–Shack aberrometer for the unaccommodated state and with 1.00 D, 2.44 D, 3.83 D, and 4.73 D of accommodative stimuli. Z(4,0) and Z(6,0) were also measured on 11.5◦ and 23◦ temporal, nasal, superior, and inferior retinal areas for unaccommodated state and for 2.44 D of accommodative stimulus. In the control group, Z(4,0) became more negative with accommodation and Z(6,0) became more positive, as was expected according to previous studies. This tendency was not observed in the group of subjects with AI group for Z(4,0) or for Z(6,0). No differences on off-axis Z(4,0) and Z(6,0) were observed between the groups. The changes of spherical aberrations with accommodation seem different in subjects with AI compared to those without any accommodative dysfunction. Those with AI do not present a decrease in Z(4,0) and an increase in Z(6,0) with accommodation as occurs in eyes without this type of dysfunction. Understanding how the optics of the eye changes with accommodation can be helpful to understand the origin of accommodative dysfunctions.