The correlation of two different subjective image quality metrics to two different optical quality metrics

Abstract

Objective To investigate the correlation of two different subjective image quality metrics to two metrics of optical quality at dark background in the patients with myopia and myopic astigmatism and to determine the better metric for the visual performance. Methods This was a prospective clinical repeated study.One hundred and twenty-three right eyes of 123 subjects with the spherical equivalent refraction (SE) from-0.50 D to-10.00 D,cylinder from 0.00 to-2.50,age from from 17 to 47 years old were investigated in this study.Itracy wavefront aberrometer was used to measure the aberration.CSV-1000E and MFVA-100 were used to measure the contrast sensitivity and 100％,25％,10％ and 5％ contrast visual acuity under the dark background,and pupil size was recorded.The high-order Zemike aberrations,strehl ratio were calculated.The area under the log contrast sensitivity function (AULCSF) was calculated based on the data obtained with the CSV-1000E sine wave grating chart.The relationship between Zemike aberrations,strehl ratio and AULCSF,multi-function visual acuity (MFVA) under dark background were analyzed. Results Multiple linear regression analysis revealed that in the dark background,AULCSF was correlated to coma (F =5.161,P ＜0.05,R2=0.041) and strehl ratio (F =5.438,P ＜0.05,R2=0.043) respectively; 100％,25％,10％,5％ contrast visual acuity was associated significantly with spherical aberration (F1=5.709,P1＜0.05,R2=0.045; F2=6.863,P2＜0.05,R2=0.054; F3=10.815,P3＜0.01,R2=0.082; F4=8.687,P4＜0.01,R2=0.067) and strehl ratio (F1=13.363,P1＜0.01,R2=0.099; F2=17.663,P2＜0.01,R2=0.127; F3=23.298,P3＜0.01,R2=0.161; F4=26.865,P4＜0.01,R2=0.182). Conclusions To predict the visual performance,it seems that the different contrast visual acuity is much precise than AULCSF,low contrast visual acuity is more sensitive than high contrast visual acuity,and strehl ratio is a better metric than RMS at dark background. Key words: Higher-order aberration; Strehl ratio; Contrast visual acuity; Optical quality metric,Visual performance