The Study On The Accommodation Stimulus Response Of The Juvenile Myopes And The Effect Of M-receptor Antagonist On The Accommodation

Part oneThe Study on the differences in accommodation stimulus response between juvenile myopes and emmetropesObjective To investigate the differences in accommodation stimulus response between juvenile myopes and emmetropes.Methods 163 subjects(aged from 5 to 15) under full correction of refractive errors with glasses viewed targets displayed at five different distances:6.0m,0.5m,0.33m,0.25m,0.20 m (163 subjects under monocular condition; 24 subjects under binocular condition). Accommodative responses were measured in the right eye with open-field autorefractor WAM-5500.Results 1.The slopes of the ASRCs for myopes was significantly shallower than the slope for emmetropes(p=0.0418); 2.Comparing three subsets of myopes with the emmetropes (F=28.14, P=0.000), no signifcant difference was detected in the slopes between the emmetropes and mild or severe myopes (p=0.135 and p=0.957, respectively). Otherwise,There existed a signifcant difference in the slopes between the emmetropes and moderate myopes(p=0.000).The slopes were not different signifcantly among the three subsets of myopes; 3 There is no signifcant difference in the slopes of the ASRCs between viewing under binocular condition and under monocular condition (p=0.0418). Conclusions Decreased ASRs may play a signicant role in the development of EOM. with early-onset myopia. No changes in the ASRs was found in the progression of myopia.The accommodative response was not more accurate under binocular conditions than under monocular conditions.Part twoThe effect of 0.5%raceanisodamine on accommodation and pupil sizeObjective To investigate the effect of 0.5%raceanisodamine on accommodation and pupil size.Methods 44 subjects (aged 7-17 years) were devided into two groups: raceanisodamine group and Mydrin-P group. Accommodation stimulus responses of two groups were measured in the right eye with open-field autorefractor at four different distances:6.0m,0.5m,0.25m,0.17 m. Biometric changes of anterior segment in raceanisodamine group were measured in the right eye at 0,-2D,-4D,-6D accommodated states.Results There was a signnicant difference in slope of accommodation stimulus response curves between pre- and post-administration of Mydrin-P (t=15.281, p=0.000), no significant difference in slope was found between pre- and post-administration of 0.5% raceanisodamine (t=1.865, p=0.692). Difference in pupil diameter between pre- and post-administration of 0.5% raceanisodamine was statistically significant at an accommodative stimulus of 0,-4D,-6D (p=0.022,p =0.007,p=0.006).No signicant difference was found between pre- and post-administration of 0.5% raceanisodamine in lens thickness at an accommodative stimulus of 0,-2D,-6D (p=0.303,p=0.168,p=0.230) and in anterior chamber depth at an accommodative stimulus of 0,-2D,-4D,-6D (p=0.681,p=0.376,p=0.468,P=0.876).Conclusions 0.5% raceanisodamine can dilate pupil and has little cycloplegic effect.