Factors Influencing Contrast Sensitivity Function in Myopic Eyes

PURPOSE To evaluate the factors affecting the area under the log contrast sensitivity function (AULCSF) in healthy myopic eyes. METHODS We retrospectively examined 201 eyes of 201 consecutive subjects (age, 31.8 ± 7.4 years (mean ± standard deviation)) with myopic refractive errors of -1.25 to -8.25 diopters (D). From the contrast sensitivity data, the area under the log contrast sensitivity function (AULCSF) was calculated. Stepwise multiple regression analysis was used to assess the factors affecting the AULCSF. RESULTS The mean AULSCF was 1.09 ± 0.09 (0.89 to 1.55). Explanatory variables relevant to the AULCSF were, in order of influence, the objective scattering index (OSI) (p = 0.018, partial regression coefficient B =  -0.032) and logMAR CDVA (p = 0.022, B =  -0.209) (adjusted R(2) = 0.231). No significant correlation was seen with other clinical factors such as gender, manifest refraction, pupil size, lens density, corneal HOAs, or ocular HOAs. CONCLUSIONS Although the great majority of the variance remains unexplained, eyes with lower OSI and better CDVA are more predisposed to show higher contrast sensitivity function. These results indicate that not only CDVA but also intraocular forward scattering may play some role in predicting the contrast sensitivity function in myopic subjects.