Clinical Study Of The Binocular Vision And Accommodation In Anisometropic Amblyopia

ObjectiveTo evaluate the changes of binocular vision and accommodation after occlusion in anisometropic amblyopia patients. Compare and analyze:(1)differences of different depths of amblyopia before treatment.(2) differences between amblyopia and control. Explore the relationship of those differences with degree of amblyopia and time of therapy.MethodsAmblyopia group:Forty patients aged from7to15years old were selected from outpatient service patients who visited Tianjin Eye Hospital from September2013to February2014.All patients went on refraction examination and filed a spectacle prescription before occlusion.Corrected vision of the worse eye was no more than0.8.Corrected vision of the fellow eye was no less than1.0and the refractive error were no more than±0.50DS.The spherical equivalent anisometropia of the two eyes was more than+1.50DS. The difference of the two eyes was more than2lines.All patients were divided into mild, moderate and severe three groups on the degree of amblyopia.The follow-up time was three months.Control group:Thirty-five volunteers aged from7to20years old whose monocular vision was no less than0.9, monocular refractive error were no more than±0.50D.Each patient had0.5%pyrazole card amine compound mydriatics refraction examination and had retinoscopy refraction.Based upon retinoscopy results,full correction glasses were given and then coved the fellow eye.Following examinations were carried out before occlusion, one and a half month,three months after occlusion.Which included the best corrected vision, binocular vision,distance and near stereopsis,accommodative facility(AF),distance and near deviation,AC/A ratio,positive and negative relative accommodation (PRA/NRA),accomrnodative amplitude (AMP), accommodative response(AR). Compare these parameters among different amblyopia groups, before and after occlusion therapy. Then analyze the causes of the differences. A P value<0.05was considered statistically significant(SPSS for Windows, Version17.0).Results1. There were no differences between amblyopia and control at following aspects: male-female ratio, age, distance and near deviation(P>0.05).2. Differences of binocular vision and near stereopsis among different amblyopia groups were significant (P<0.05). while that of distance and near convergence/divergence function was not evident(P>0.05). Differences of binocular and amblyopic eye’s AMP,accommodative lag(AL),AF,binocular PRA among different degrees of amblyopia were statistically significant(P<0.01).3. Distance convergence/divergence vision were examined by triple prism,their break points did not change much after one and a half months(P>0.05),3months later the differences were statically significant(P<0.05).Near divergence by Base in triple prism,their break points did not change much after one and a half months(P>0.05),while three months later the difference was evident(P<0.05).Near convergence by Base out triple prism,the differences of their blur points and break points were significant(P＜0.05),and more evident three months later(P<0.01).Compared to control group,all the breakdown points were higher,and the differences of the two groups were statistically significant(P＜0.05).(as indicated of chart7).Compared amblyopia to control,differences of distance deviation and binocular AL of them were both significant(P＜0.05),while they were insignificant after three months’ occlusion (P>0.05).Differences of amblyopic eye’s vision,binocular fusion and stereopsis compared to nonocclusion were significant(P <0.01).Near exodeviation and AL decreased much.When compared to nonocclusion and control,differences of binocular CMP,AF,PRA,AL and AC/A ratio were statistically significant(P＜0.05)..4. AF,AMP and AL of amblyopic eye and the fellow eye were compared before and after one and a half months’ treatment,and found that differences were all significant(P<0.01). The differences were still evident after3months(P<0.05).Differences of all the accommodation parameters of the two eye of control were statistically insignificant(P>0.05).Every eye’s AF and AMP of amblyopic patients and AL of amblyopic eye were compared to control before and after treatment,differences were all statistically significant(P<0.05).There were not evident differences of AL between of amblyopias’fellow eye and control before and after treatment(P>0.05)Conclusions 1. There were evident difference of binocular vision and accommodation function among different degrees of amblyopia.The worse the amblyopia,the worse binocular vision and the lower accommodation.Influence on distance and near convergence/divergence of the degree of amblyopia was not evident.2. Binocular vision and accommodation function of anisometropic amblyopia patients were both damaged. All improvements of binocular vision and accommodation function were evident after occlusion and the longer the time was, the more evident the effect.4. Accommodation of amblyopic eye stayed lower than the fellow eye and normal eye before and after treatment.The fellow eye also show worse accommodation function than the normal eye.