| Objective: To study the changes of configuration and position of the ciliary body of normal human eyes in spontaneous far-to-near accommodation. To analyze the differences of the anterior segment of eye among groups with different refractive error, and to investigate the differences of the changes of the ciliary body in spontaneous accommodation among groups with different refractive error.Methods: The pictures of the ciliary body area of 56 normal human eyes were captured by ultrasound biomicroscopy(UBM) when the subjects focused on far and near optotypes respectively. Measure the configuration-related parameters and the position-related parameters of the ciliary body in all the pictures, compare the parameters of non-accommodation and accommodation states using Paired t-test. Then divide the subjects into three groups: emmetropia, low and medium myopia, high myopia. Measure in the UBM pictures the corresponding parameters of the anterior segment of non-accommodation and accommodation states respectively, compare the parameters among the three groups using One-Way ANOVA. Next, calculate the change amplitude of all the parameters from non-accommodation toaccommodation states. Compare the change amplitude of the parametersamong the three groups using One-Way ANOVA. And the change amplitudeof the parameters was correlated with diopter by Bivariate Correlation andPartial Correlation.Results:A. During accommodation, the ciliary process turned longer and narrower,and it moved inward and forward. And the angle of anterior chamberdiminished(P<0.05).B . In non-accommodation state, the ciliary cody was thicker, moreposteriorly in myopia than in emmetropia, and the angle of anterior chamberwas wider in myopia(P<0.05 ).C. During accommodation, the change amplitude of the configuration andposition of the ciliary body was minor in myopia than in emmetropia(P<0.05).The configuration change amplitude was correlated with diopter.Conclusions: During accommodation, the ciliary process of human eyemoved inward and forward, to accord with the Helmholtz theory. Theround-muscle plays major part in accommodation. During accommodation,the change amplitude of the configuration and position of the ciliary bodywas minor in myopia than in emmetropia. The ciliary body was thicker andmore posteriorly in myopia than in emmetropia. This gives us a hint thatdeteriorating of myopia may be caused by the adynamia of the ciliary muscle.We could treat myopia through training ciliary contracting power. |
