AIM: To compare the differences and correlations between different types of anisometropia, binocular visual acuity and biological parameters in school-age children.

METHODS: A total of 128 school-age children(6-12 years)with mild-to-moderate anisometropia were retrospectively analyzed. Subjects were divided into five groups according to anisometropia type. All participants underwent cycloplegic refraction, A-scan ultrasound biometry, and corneal topography. Refractive status, best-corrected visual acuity(BCVA), anterior chamber depth(ACD), lens thickness(LT), vitreous chamber depth(VCD), axial length(AL), corneal radius(CR), and ratio of AL and CR(AL/CR)were recorded. Kruskal-Wallis and Spearman rank correlation tests were then used for statistical analysis.

RESULTS: Hyperopic anisometropia had the greatest binocular vision difference(0.14±0.20). Myopic anisometropia had the greatest asymmetry in AL and VCD(0.56±0.41 and 0.56±0.39 mm, respectively). Anisometropia was positively correlated with BCVA, VCD, AL, and AL/CR(r=0.266, 0.379, 0.350, 0.263, respectively; P<0.05), and it was not significantly correlated with LT and CR(r=-0.019,-0.069, respectively; P>0.05), while no parameters had a statistically significant correlation with anisometropia in each group.

CONCLUSION: School-age children with hyperopic anisometropia showed the greatest difference of binocular acuity in the four types of anisometropia. The inter-ocular differences of biometric parameters in simple hyperopic or myopic anisometropia were mainly attributed to the asymmetry of VCD and AL, while the differences in ocular parameters were not statistically significant in school-age children with astigmatic anisometropia.