Investigation Of The Asymmetry Analysis Of Multifocal Visual Evoked Potentials In Early Diagnosis Of Glaucoma

ObjectiveTo study the characteristic of multifocal visual evoked potentials response between the two eyes of control subjects ; and study the change of the interocular asymmetry of mVEP in primary open angle glaucoma and high risk patient with suspected glaucoma ;to determine the efficacity in diagnosis , detection and follow up of early glaucomatous damage. MethodsThe pattern mVEP of both eyes of 30 POAG patients , 24 suspected glaucoma patients and 30 control subjects were recorded by VERIS Science^? 4.2 Multifocal Visual Evoked Response Imaging System. The amplitudes and latencies of P waves were analyzed. All subjects were recorded visual fields in both eyes with OCTOPUS 101 perimeter in the same day that they were recorded the mVEP with VERIS Science? 4.2.The pattern mVEP and visual fields of 3 control subjects were recorded in four separate days.A response asymmetry coefficient (RAC) were determined for both latencies and amplitudes each quadrant of VEP fields. Result1. The waveform, amplitudes and latencies in the two eyes of mVEPin control subjects are almost identical.2. The repeat reliability of the RAC value of mVEP of control subjects was studied. In a certain normal subject, at each quadrant of VEP field, the RAC value showed little variability between tests.3. At each quadrant of VEP fields, the RAC value of the amplitudes of POAG patients increased compared with suspected glaucoma patients and control subjects .While At each quadrant of VEP fields, the RAC value of the latencies of POAG patients patients increased compared with suspected glaucoma and control subjects. At the inferotemporal quadrant of VEP fields, the RAC value of the latencies of suspected glaucoma patients increased compared with control subjects .4. There is the correlationship between the amplitudes RAC value of mVEP and the interocular comparison of mean sensitivity of visual field in POAG patients were studied. The amplitudes RAC values in POAG patients increased with the interocular difference of MS values increased; The latencies RAC values in POAG patients reduced with the interocular difference of MS values increased.Conclusion1. The symmetry of waveform > amplitudes and latencies in the two eyes of mVEP in control subjects are good.2. The RAC value of mVEP show good repeat reliability in control subject; so it can be used to follow up the suspected glaucoma patients and detect the early glaucomatous damage .