| Background and purpose:Amblyopia is due to abnormal visual experience in visual system development critical period of children and result in single eye or biocular best crrected visual acuity decreasing.There is no visiable organic disease in the patients' eye.The adult amblyopia patients hardly increase their visual acuity.Now,the visual perceptual trainning can increase the visual function of these patients shortly,but after stop the trainning,the visual function of amblyopia eye will decreas again.It is possible due to the visual central system can not utilize the visual information of amblyopic eye very well,and do not utilized it persistently.The visual attention play a key role in the visual informaiton processing and utilizing,so we infer that there is visual attention function deficits is amblyopes,and it result in weakly utilizing of visual information of amblyopic eye,and also result in hardly to increase the visual function of amblyopic eye.In another hand,in strabismic amblyopia,all of the eyeball movement function,fixation and binocularsynergy function was damaged,and it result in the eye ball movement related visual function deficits.Eye ball movement and fixation function is very important for visual attention funcion,but in strabismic amblyopes,the abnormal function of eye ball movement and fixation would result in the deficits of visual attention function.Therefore,we suppose that: in strabismic amblyopia,the visual attention deficits due to abnormal eye ball movement funcion is the key reason of visual funcion deficits in amblyopia.So,this study utilized the psychophysical and f MRI method to research the visual attention function of adult strabismic amblyopes,and observed whether there is visual attention related brain areas dificits in this disease.We hope to declare the visual function deficits characteristics and the cortical bases of related brain funcion deficits.Methods:1.Utilizing the motion-driven attention speed threshold task to measure the speed threshold of amblyopic and fellow eye of amblyopes and the dominant and non-dominant eye of normal subjects,to prove whether there is visual attention function deficits in amblyopic eye;2.Utilizing the bottom-up motion-driven attention task and top-down saccade task and f MRI method to collect the brain function change of adult strabismic amblyopes and normal subjects when they are doing the 2 visual attention tasks,and analyze whether there is functional deficits in the visual attention related brain areas;3.Based on the f MRI data of motion-driven attention task and saccade task to analyze the functional connectivities in different visual attention related areas to research whether there is dificits in functional connectivities;4.Utilized the resting fMRI method to research the correlation of V1 and whole brain and compared the difference between amblyopia patients and normal subjects.Results:1.In the motion-driven attention speed threshold task,the speed threshold of amblyopic eye is significantly lower than the fellow eye and the dominant/ non-dominant eye of normal subject;the speed threshold of fellow eye is not different with the two eyes of normal subject;there is no difference between the two eyes of normal subject.It show that in adult strabismic amblyopia,there is motion-driven visual attention deficits of amblyopic eye comparing with fellow eye and dominant/ non-dominant eye of normal subject.2.In the motion-driven attention task,the activiation intensity and speed of V1 of amblyopic eye is not significantly different with the fellow eye,dominant eye and non-dominant eye;the activation intensity and speed of IPS and FEF area of amblyopic eye is significiantly lower than the fellow eye,dominant eye and non-dominant eye;the activation intensity and speed of V1,IPS and FEF offellow eye is not significantly difference with the two eyes of normal subject;the activation intensity and speed of V1 IPS and FEF of dominant/ non-dominant eye of normal subject is not significantly difference.It show the in bottom-up visual attention task,the V1 area function of amblyope is normal,but the function of visual attention related areas(FEF and IPS)is deficits.3.In saccade task,the activiation intensity and speed of V1,IPS and FEF area of amblyopic eye is significantly lower than the fellow eye,dominant eye and non-dominant eye;the activiation intensity and speed of V1,IPS and FEF area of fellow eye is not significantly differenct with the two eyes of normal subjects;the activiation intensity and speed of V1,IPS and FEF area of dominant/ non-dominant eye of normal subject is not significantly difference.It show that in top-down visual attention task,the function of V1 area and visual attention related area(FEF and IPS)is deficits.4.In the motion-driven attention task,the functional connectivity of both side V1 and IPS of amblyopic eye is not significantly difference with the fellow eye,dominant eye and non-dominant eye;the functional connectivity of the ipsilateral FEF of amblyopic eye with the contralateral FEF and both side IPS is significantly weaker than the fellow eye,but it is not significantly different with the two eyes of normal control;all of the functional connectivity of fellow eye is not significantly different with the two eye of normal subject;all of the functional connectivity of dominant/ non-dominant eye of normal subject is not significantly difference.It show that when the amblyopic eye do the bottom-up visual attention task,the function connectivity of V1 and IPS area is not dificit.The visual attention network deficits of amblyopic eye is the ipsilateral FEF was relatively isolated in bottom-up visual attention task.The function connectivity V1 IPS and FEF of the fellow eye of amblyope in bottom-up visual attention task is normal.5.In saccade,all of the functional connectivity of amblyopic eye,fellow eye,dominant eye and non-dominant eye is not significantly difference.It show that the all of the functional connectivity of V1 IPS and FEF in top-down visual attention task is normal.6.In resting,the functional connectivity of V1 with itself and the around cortical areas of amblyope is significantly decreased comparing with normal subject;but the functional connectivity of V1 with default network is significantly increased comparing with normal subject.It is another brain function base of visual attention deficit.Conclusions:1.In adult strabismic amblyopia,there is motion-driven visual attention deficits of amblyopic eye comparing with fellow eye and dominant/ non-dominant eye of normal subject.2.The amblyopic eye function of V1 area is normal in bottom-up visual attention function,but it is dificits in top-down visual attention function.3.The visual attention related areas(FEF and IPS)function is weaker than the 3 groups of control eye in bottom-up and top-down visual attention tasks.It is the first brain function base of visual attention dificits.4.The main characteristic of the function connectivity of amblyopic eye is that the amblyopic eye ipsilateral FEF was relatively isolated in bottom-up visual attention task,but the function connectivity is normal in top-down task.It is the second brain function base of visual attention dificits.5.In resting,the functional connectivity of V1 with default network is significantly increased,but with itself and the around cortical areas of amblyope is significantly decreased.It is the third brain function base of visual attention dificits.6.The function connectivity of V1 and IPS of amblyopic eye is normal in both of bottom-up and top-down visual attention tasks. |
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