Comparison of changes in ocular aberrations with accommodation and accommodative facility

Abstract

Aims/Purpose: This study aimed to analyse whether a relationship exists between subjectively measured monocular Accommodative Facility (AF), the magnitude of the revolution‐symmetric Zernike coefficients C20, C40 and C60, and the objectively measured Accommodative Response (AR).Methods: A total of 66 eyes, from 33 healthy young volunteers (26 women and 10 men) with a mean age of 25.12 ± 3.40 years (range age 20–30) participated in this study. Three measurements were made for each eye with the aberrometer Hartmann‐Shack (IRX3, Imagine Eyes, Orsay, France). The stimulus vergence was increased from 0 to 5 D (near vision) in steps of 0.5 D. The AR for each Zernike coefficient was calculated as the difference between the value at 5 D and the value at 0 D, for 4.0 mm pupil size. Monocular assessment of AF was assessed monocularly and conducted at 40 cm ± 2.00 D flippers. Statistical analysis was performed to determine a relationship between the Zernike coefficients, AR and AF. The coefficient of determination (R‐squared) was calculated to measure the proportional amount of variance.Results: The results showed that the highest values of R‐squared were obtained for the C20 coefficient measured at 5D of accommodation (R2 = 0.196, p < 0.01). Lower values were obtained for C40 and C60. The R‐squared values decreased from 0D (R2 = 0.097, p = 0.10) to 5D (R2 = 0.044, p = 0.60) for C40. However, there was an increase in R‐squared values from 0D (R2 = 0.0081, p = 0.47) to 5D (R2 = 0.058, p = 0.05) for C60.Conclusions: No clear trends were found when comparing the Zernike coefficients C20, C40 and C60, analysed in three stages of accommodative demand compared with the accommodative facility measured.The Zernikes coefficients analysed do not explain the differences in AF in this sample of young adult healthy eyes. However, there was found a trend that deserves further investigation.