DTI Application And Study Of Visual Pathway In Children With Congential Esotropia

Objective: To study the application value of magnetic resonance diffusion tensor imaging(DTI)in visual pathway of congential esotropia(CE).Materials and methods: DTI imaging was performed in 21 CE children(13 males and 8females),and 21 healthy volunteers(13 males and 8females)with macthed age,gender and education.The fractional anisotropy(FA),the mean diffusivity(MD),the axial diffusion tensor(AD),and the vertical diffusion tensor(RD)of optic chiasma,corporis callosi splenium and bilateral ophthalmic tract,Lateral Geniculate Nucleus,optic radiation(white matter fiber tract under visual cortex in broadmann area 17 region)were obtained.The diopter of equivalent sphere mirror as a clinical indicator was collected.The statistical analysis was performed.To explore the changes of DTI parameters in children with congential esotropia and to compare the differences between them.To find the correlation between the changes of FA values and the clinical indicators.Results:(1)There were no significant differences between the left and the right of ophthalmic tract,Lateral Geniculate Nucleus and optic radiation in all relevant paremeters of CE group(P>0.05).(2)Compared with the control group: The FA value were no significant differences at optic chiasma of CE group(P>0.05).The FA value decreased and the value of MD value and AD value increased in the group of CE at corporis callosi splenium and bilateral ophthalmic tract,Lateral Geniculate Nucleus,optic radiation(P<0.01).RD value increased in the group of CE at optic chiasma,corporis callosi splenium and bilateral ophthalmic tract(P<0.01).(3)The correlation analysis of the changes of the visual pathway FA value in the CE group and the diopter of equivalent sphere mirror: There was a linear negative correlation between FA values and the diopter of the equivalent lens in optic radiation(r=-0.738,P<0.01).There was no linear correlation between FA value and the diopter of the equivalent lens in optic chiasma,corporis callosi splenium,ophthalmic tract,Lateral Geniculate Nucleus.Conclusion:(1)white matter of visual pathway of CE children are changed obviously,suggesting that the myeloid sheath of white matter fibers are varying degrees of damaged or poorly developed.(2)The variation amplitude of the DTI parameter value of the optic radiation is relatively large and there is a negative correlation between the FA value and the diopter.It suggest that white matter fiber in the optic radiation of visual pathway may be more easily and seriously affected by the strabismus.The change of the FA value can reflect the severe range of the children's visual impairment to a certain extent.(3)DTI-based fiber imaging can directly reflect the changes in the microstructure of the white matter fiber bundle,and provide a quantifiable index.It has a good application and research value for children with congenital esotropia.