Visual Benefits Of Optical Or Occlusion Treatment In Monocular Amblyopia Assessed By Binocular Phase Combination Paradigm

Background and Objective Amplyopia is a common disease whose best corrected visual acuity is lower than contemporary which results form deprivation during visual development.Several studies have shown that patients with amblyopia not only have poor monocular visual function but also binocular visual deficits and stereopsis.Recently,researchers have switched their eyes from the monocular loss in amblyopia to binocular interactions.Several studies have shown the importance of suppression in the deficit of amblyopia.Previous amblyopic therapies can significantly improve visual acuity in most types of amblyopia.In this study we raise a further question: can the sensory eye balance of amblyopes also be restored by the traditional amblyopic treatments? The aim of this study is to assess monocular visual benefits and binocular visual benefits of optical or occlusion treatment in monocular amblyopia.Methods Monocular amblyopic patients were recruited from the department of Ophthalmology of the First Affiliated Hospital of Anhui Medical University(from April 2016 to October 2017).And they were newly diagnosed and had never received any treatment(includes spectacle wear or occlusion)before they participated in this study.All anisometropic amblyopia patients were asked to wear spectacles all day long for 2 months before the occlusion treatments.And we measured monocular and binocular visual benefits(including the best corrected visual acuity at distance,sensory eye balance and stereopsis)of optical treatment before the treatment and 1 month,2 months after the treatment.For the strabismic amblyopia and anisometropic amblyopia who have conducted 2 months optical treatment were treated by occlusion.We also measured monocular and binocular visual benefits(including the best corrected visual acuity at distance,sensory eye balance and stereopsis)of occlusion therapy before the treatment and 2 weeks,1 month,2 months,4 months,6 months after the treatment.For statistical analysis,SPSS 24.0 was used.The pre-and post-optical or occlusion treatment measures were compared using paired samples t-test.All the relationship was evaluated by using Pearson correlation analysis.Results(1)The mean visual acuity(in log MAR)of the amblyopic eyes of 14 anisometropic amblyopia before optical treatment was 0.59 ± 0.26(Mean ± SD;same for the following expressions)and it significantly improved to 0.44 ± 0.25 after two months of spectacle wearing(t(13)= 5.940,p < 0.001);The mean effective contrast ratio at balance point was 0.22 ± 0.11 before optical treatment and it significantly increased to 0.31 ± 0.09 after two months of spectacle wearing(t(13)=-3.289,p = 0.006);The mean stereopsis of the patients at baseline was 1670 ± 1399 arc seconds before optical treatment and it significantly increased to 947 ± 1351 arc seconds after two months of spectacle wearing(t(13)= 2.362,p = 0.034).(2)The mean visual acuity(in log MAR)of the amblyopic eyes of 33 monocular amblyopia before occlusion treatment was 0.60 ± 0.24(Mean ± SD;same for the following)and it significantly improved to 0.40 ± 0.21 after two months of occlusion(t(32)= 7.79;p < 0.001),0.30 ± 0.18 after six months of occlusion(t(32)= 11.34;p < 0.001);The mean effective contrast ratio at balance point of 33 monocular amblyopia before occlusion treatment was 0.23 ± 0.10 and it significantly improved to 0.37 ± 0.22 after two months of occlusion(t(32)=-3.335;p = 0.002),0.40 ± 0.23 after six months of occlusion(t(32)=-3.80;p = 0.001);The mean stereopsis of the patients at baseline was 1662 ± 1407 arc seconds and it significantly improved to 989 ± 1358 arc seconds after two months of occlusion(t(32)= 3.49;p = 0.001),967 ± 1368 arc seconds after six months of occlusion(t(32)= 3.47;p = 0.001).Conclusion(1)We conclude that optical treatment improves interocular sensory balance in anisometropic amblyopia as well as monocular acuity.Optical treatment is an efficient form of binocular therapy and a necessary first step in treating the binocular dysfunction that characterizes amblyopia.(2)Occlusion is also an effective treatment that can improve binocular visual function as well as monocular acuity in monocular amblyopia.