Preliminary Study On Reading Acuity,binocular Acuity And Monocular Acuity

Objective To study the relationship among reading acuity,binocular acuity and monocular acuity experimentally.To analyze types,mechanism and forensic identification for traumatic visual loss.Methods(1)Experimental section Reading acuity,binocular acuity and monocular acuity were measured in subjects with acuity of at least 4.9(0.8)in each naked eye and degraded binocularly(Group A)and monocularly(Group B)with Bangerter filters.Group A uses Bangerter filters 0.1*0.2(0.1 and 0.2 stacked together),0.1,0.3 and 0.6.Group B uses Bangerter filters 0.1*0.2*0.2*0.3(0.1,0.2,0.2 and 0.3 stacked together),0.1*0.2,0.3 and 0.6.Interocular difference,binocular summation and the difference between reading acuiy and the better eye were counted.Correlation analysis and regression analysis were based on reading acuity,binocular acuity a nd monocular acuity.(2)Investigation section 109 cases of the evaluation for impairment and disability on traumatic visual loss were retrospectively analyzed,including interocular differences,anisometropia,left or right eye and the distributions of visual acuity,etc.Results(1)Experimental section 14 subjects(aged 19 to 22 years)were recruited.The male-to-female ratio was 3:4.?In Group A,Reading acuity was correlated with binocular acuity,the better eye acuity and the worse eye acuity(r=0.700,0.683,0.683,P<0.001).Binocular acuity was correlated with the better eye acuity and the worse eye acuity(r=0.860,0.891,P<0.001).In Group B,Reading acuity was correlated with binocular acuity,the better eye acuity and the worse eye acuity(r=0.544,P<0.001;r=0.572,P<0.001;r=0.041,P=0.714).Binocular acuity was correlated with the better eye acuity and the worse eye acuity(r=0.634,P<0.001;r=-0.008,P=0.939).?With vision degraded binocularly,the mean interocular difference was 0.6 line and t he mean binocular summation was 1 line;With vision degraded monocularly,the mean interocular difference was 8.6 line and the mean binocular summation was 0.2 line(Z=-5.091,P<0.001).Reading acuity was lower than binocular acuity.?3 In Group A,the regression equation between binocular acuity(Y)and the worse eye acuity(X1)was Y=0.973X1+0.219,P<0.001.The regression equation between binocular acuity(Y)and the better eye acuity(X2)was Y =1.018X2+0.039,P<0.001.The regression equation between binocular acuity(X3)and reading acuity(Yr)was Yr=0.867X3+0.144,P<0.001,R2=0.691.In Group B,the regression equation based on binocular acuity(Y),the worse eye acuity(X1)and the better eye acuity(X2)was Y =0.807X2+0.007X1+0.974,P<0.001,R2=0.574.The regression coefficient of the worse eye acuity had no statistical significance.The regression equation between binocular acuity(X3)and reading acuity(Yr)was Yr=0.449X3+2.451,P<0.001,R2=0.405.(2)Investigation section The male-to-female ratio was 5.8:1,mainly 30~59 years of age.The ratio of monocular versus binocular injuries was 17.17:1.The ratio of left versus right injured eye was 1.39:1 in intentional injury cases.115 eyes were injured,83 of which were in low vision or blindness.95 patients(87.16%)had large interocular differences(?3 lines).There were 43 patients(39.45%)with anisometropia?1.00 D,of which 23 patients were more than 6.00 D.The ratio of hyperopic anisometropia was the highest,accounting for 44.19%(19/43).Conclusion Reading acuity was highly correlated with both binocular acuity and the better eye acuity,while weakly correlated with the worse eye acuity.Interocular difference may reduce binocular summation.Interocular differences and anisometropia are common in practice.Functional vision should be considered when developing the expertise standard.