The aim of this study was to investigate effects of refractive correction on the visual acuity and binocular visual function in ametropic children.

A total of 156 children (312 eyes) with anisometropic amblyopia and ametropic amblyopia recruited from November 2017 to September 2018 in Beijing Tongren Eye Center, Beijing Tongren Hospital affiliated to Capital Medical University were analyzed prospectively with non-randomized control. Among of them, there were 70 male (140 eyes) and 86 female (172 eyes) with an average age (5.7±1.6) years-old (ranged from 3 to 12 years-old). According to the nature of anisometropia and ametropia, they were divided into anisometropic amblyopia group and ametropic amblyopia group. The uncorrected visual acuity, best corrected visual acuity (BCVA), refractive status, optometry under ciliary paralysis were examined. All children were given prescription glasses according to their age and refractive status, and the BCVA and optometry under ciliary paralysis, near and far stereopsis and perception examination were performed after refractive correction for 3 months. The age, equivalent spherical lens, best corrected visual acuity, stereoacuity, cross non cross parallax and static stereopsis were performed normality test. Continuous variables conforming to normal distribution were expressed by ±s, and compared using independent t test. Different eyes of the same patient and before and after refractive correction were compared using paired t test. Otherwise, indices were expressed by median and upper and lower quartiles, and compared using non-parametric test. Countable data such as gender, telestereopsis and dynamic stereopsis was expressed by cases and percentage, and compared using Chi-square test.

There were 112 cases (224 eyes) with anisometropic amblyopia and 44 cases (88 eyes) with ametropic amblyopia. There was no statistically significant difference in gender distribution between two groups (χ²=2.88, P>0.05). There was statistically significant difference in age distribution (t=-5.28, P<0.05). In anisometropia amblyopia group, the BCVA of children before and after the referactive correction for 3 months were (0.42±0.23), (0.29±0.16), respectively; for ametropia amblyopia group, those were (0.49±0.18), (0.33±0.15), respectively. The BCVA was significantly higher than that before correction with significant difference (t=-6.84, -7.50; P<0.05). The BCVA of different subtype′s anisometropia amblyopia group such as hyperopia, astigmatism and hyperopia combined with astigmatism were (0.28±0.16), (0.23±0.13), (0.37±0.17), respectively; for ametropia amblyopia group, those were (0.37±0.14), (0.27±0.12), (0.39±0.19). There was statistically significant difference between subgroups before and after correction (t=-3.25, -4.02, -6.48, -4.62, -6.08, -2.91; P<0.05). The positive distant stereoscopic vision of anisometropia amblyopia and ametropia amblyopia after correction were 33 cases and 21 cases, accounting for 29.46% and 47.73%, respectively with statistically difference between them (χ²=4.65, P<0.05). In anisometropia amblyopia group, near (stereopsis acuity, crossed disparity, non-crossed disparity), static stereoscopic vision and perceptual eye position (level large eye position, vertical large eye position, level small eye position, vertical smal eye position) were (2.38±0.57)″, (3.45±0.41)″, (3.44±0.40)″, (2.56±0.34)″, (47.10±43.17) pls、(23.39±20.23) pls, (45.24±36.08) pls, and (25.30±20.60) pls. The ametropia amblyopia group performed better in the distant stereo vision and perceptual eye position, while the anisometropia amblyopia group performed better in the near stereo vision. There was statistically significant difference between groups (t=3.20, -2.72, -2.69, -2.87, -2.66, -2.13, -3.26, -2.02; P<0.05). The dynamic stereovision of anisometropia amblyopia group with no pass, low pass and high pass were 51 cases, 29 cases, 32 cases, accounting for 45.54%, 25.89%, 28.57%, respectively. There was non-significant difference between groups (χ²=4.43, P>0.05).

Short-term refractive correction was effective in the treatment of amblyopia in children, and there were differences in stereoscopic vision after refractive correction between amblyopia and anisometropia. Visual perception examination could be used to evaluate binocular visual function more comprehensively in clinical practice.