An Assessment of the Contrast Sensitivity in Patients with Ametropic and Anisometropic Amblyopia in Achieving the Corrected Visual Acuity of 1.0

Both visual acuity (VA) and contrast sensitivity (CS) are important parameters for measuring visual function. In this research, we investigated the CS of patients with ametropic or anisometropic amblyopia, whose corrected visual acuity (CVA) recovered to 1.0. Fifty-five cases with amblyopia and 22 control cases with a normal visual acuity of 1.0 were enrolled. The CS of the patients whose ametropic amblyopia had recovered to a CVA of 1.0 at 18 cpd spatial frequency was still lower than that of the normal control group under both photopic and scotopic conditions (P = 0.001, 0.025), but there were no significant differences at low- and middle-spatial frequencies. The CS of amblyopic eyes of the patients with anisometropic amblyopia was lower than that of the normal control group at the 18 cpd spatial frequency under photopic conditions (P = 0.005), and at the 6 cpd, 12 cpd, and 18 cpd spatial frequencies under scotopic conditions (P = 0.008, <0.001, 0.004, respectively). The CS between the amblyopic eyes and the sound eyes of patients with anisometropic amblyopia presented significant differences at the 6 cpd, 12 cpd, and 18 cpd spatial frequencies under scotopic conditions (P = 0.025, 0.045, 0.019, respectively). We suggest that amblyopia treatment should involve not only the correction of VA but also the improvement of CS.