[Association between ocular dominance and refraction in myopic subjects]

Objective: To determine the association between ocular dominance and myopic-astigmatic characteristics in myopic subjects. Methods: Cross-sectional study. A total of 1 503 myopic subjects visiting from the myopiac clinic from December 2011 to December 2012 were included. The spheres and cylinders were recorded. The ocular dominance was determined by the hole-in-the-card test. The average spherical equivalent (SE) and the cylinder between the dominant eyes and the non-dominant eyes were compared with the paired t test. The associations between ocular dominance laterality and refractive characters were analyzed with the crosstab Chi-square test. Results: There were 527 males and 976 females in this study. The median (min, max) of age was 24 (17, 49) years old. Among the subjects, 66.00% (992/1 503) of subjects were right-eye dominant, while 34.00% (511/1 503) of subjects were left-eye dominant. The dominant eyes had significantly lower average sphere powers ［(-5.01±1.91) D vs. (-5.10±1.99) D］ and lower average cylinder powers ［(-0.70±0.68) D vs. (-0.76±0.73) D］ than the non-dominant eyes (t=2.976, 4.319; both P<0.01). In the subgroups of |ΔSE|≤0.50 D, 0.50 D<|ΔSE|≤1.00 D, 1.00 D<|ΔSE|≤2.00 D and |ΔSE|>2.00 D, respectively, the dominant eyes were lower myopic in 49.37% (355/719), 51.10% (163/319), 58.48% (100/171) and 65.56% (59/90) of the subjects. The inter-group difference was statistically significant (χ²=11.588, P=0.009). In the subgroups of |ΔCyl|≤0.25 D, 0.25 D<|ΔCyl|≤0.50 D and |ΔCyl|>0.50 D, the dominant eyes had lower astigmatism in 53.94% (89/165), 65.66% (65/99) and 69.70% (46/66) of the subjects, respectively. The inter-group difference was statistically significant (χ²=6.414, P=0.040). Conclusion: The ocular dominance laterality is significantly associated with lower myopia and lower astigmatism in the myopic subjects. (Chin J Ophthalmol, 2020, 56: 693-698).