Changes of refraction power and higher-order aberrations under mesopic and photopic conditions in myopic eyes

Yi SONG; Yan WANG; Tong CUI; Jiaonan MA

ABSTRACT

Objective:

To investigate the changes of refraction power and higher-order aberrations under mesopic and photopic vision conditions.

Methods:

A cross-sectional study was performed.Seventy-one eyes of 71 patients with myopia or myopic astigmatism were enrolled in Tianjin Eye Hospital from February 6 to 28 in 2017.Spherical diopter, cylindrical diopter and higher-order aberrations were examined with NIDEK OPD Scan-Ⅲ.The pupil size, refractive power, total higher-order aberrations and Zernike aberration coefficients were compared between mesopic and photopic conditions.The study protocol was approved by an Ethics Committee of Tianjin Eye Hospital.Written informed consent was obtained from each subject prior to any medical examination.

Results:

The mean pupil diameter of the photopic conditions was significantly smaller than that of mesopic condition ( t=-66.730, P<0.001). The mean spherical equivalent (SE) were (-6.85±2.75)D and (-6.50±2.38)D under mesopic and photopic conditions, and mean cylindrical diopter were (-1.27±0.91)D and (-0.84±0.76)D, respectively, with statistically significant differences between the two conditions (both at P<0.001). There was no significant difference in spherical diopter between photopic and mesopic conditions ( P=0.212). The root mean square (RMS) values of total higher order aberration, total trefoil, total coma and total spherical aberration under mesopic condition were significantly higher than those under photopic condition (all at P<0.001), and the RMS values of Zernike aberration coefficients were significantly increased in mesopic condition compared with the photopic condition (all at P<0.001).

Conclusions:

Both refractive power and higher-order aberrations in photopic condition are higher than those in mesopic condition.