Abstract
Purpose :
The increase of spherical aberration with enlarging human pupils is discussed as a reason for a myopic refractive shift in mesopic light conditions. Aim of this study was to investigate the correlation between spherical aberration and subjective refraction in mesopic luminance.
Methods :
Right eyes of 96 subjects aged from 18 to 40 were analyzed in this prospective study. For aberrometric determination of spherical aberration and objective refraction data a Hartmann-Shack aberrometer Visionix VX 120 (Luneau Technology SAS, France) was used. Aberrometry data were collected for 3 mm and maximum pupil size. Subjective refraction was obtained under both, photopic and mesopic light conditions. In this course, pupil size was tracked with an infrared camera.
Results :
Aberrometric spherical equivalent change between 3 mm pupil size and maximum pupil size was -0.24 ± 0.32 D (p<0.001). In subjective refraction, spherical equivalent shift in mesopic light conditions was -0.28 ± 0.17 D (p<0.001). However, aberrometric refractive shifts were not comparable to subjective refractive shifts. There was a strong correlation between spherical aberration and pupil-size dependent aberrometric refractive shift (r=0.949, p<0.001) but a weak correlation between spherical aberration and subjective luminance-dependent refractive shift (r = 0.330, p<0.01).
Conclusions :
The impact of spherical aberration on subjective night myopia is not significant. According to the results of this study, for optometry, the relevance of theoretical physical calculation models based on aberrometry should be reconsidered.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.