The Application Of Multifocol Electroretinogram In Early Diagnosis Of Diabetic Retinopathy

Objective:To evaluate the effect of multifocal electroretinogram(mf-ERG) in detecting the early retinal abnormalities in diabetic patients and to provide evidences and ways for the prevention and cure of diabetic retinopathy.Methods:The first and second order kernel(FOK,SOK) responses of mf-ERG were recorded on each eye of 30 normal control subjects(56 eyes)and 32 diabetic patients without retinopathy(58 eyes) and 21 mild non-proliferative diabetic retinopathy(42 eyes) by GT-2000NV visual electro-physiologic system. The stimulating pattern is composed of 63 units,which united to be a concentric circular array of black and white.The amplitude and implicit time of each local retinal responses were derived and compared amang the three groups.Vision test,slit lamp microscope, direct ophthalmoscope,non-contact tonometer, fundus photography and FFA were also performed on each eye. The implicit time and amplitudes of a wave and b wave and response densities of b wave were analyzed by SPSS11.5 software. Difference is considered significant at P<0.05.Results:1.FOK response: In NDR group, the overall amplitudes of b wave in the sum response were reduced significantly. The implicit time of a wave were increased significantly in ring 0.The implicit time of b wave were increased significantly in inferior-temporal quadrant(IT) and superior-temporal quadrant(ST). The overall amplitudes of a wave were reduced significantly in ring 0～3 and IT and ST.The overall amplitudes of b wave were reduced significantly in ring 0 and ring 2.The response densities of b wave were reduced significantly in ring 0. In DR group, the implicit time of a wave and b wave were increased significantly in the sum response and the overall amplitudes of them were reduced significantly.The implicit time of a wave were increased significantly in ring 0 and IT and ST.The implicit time of b wave were increased significantly in ring 0～3 and IT and ST.The overall amplitudes of a wave were reduced significantly in ring 0～2 and IT and ST. The overall amplitudes of b wave were reduced significantly in ring 0～4 and IT and ST. The response densities of b wave were reduced significantly in ring 0～2 and IT and ST and superior-nasal quadrant(SN)(p<0.05).2.SOK respose: In NDR group, the implicit time of b wave in the sum response were increased significantly.the overall amplitudes of a wave in the sum response were reduced significantly. The implicit time of a wave were increased significantly in ring 0～1. The overall amplitudes of b wave were reduced significantly in ring 0～1 and IT. The response densities of b wave were reduced significantly in SN and ST. In DR group, the implicit time of b wave were increased significantly in the sum response.The overall amplitudes of a wave and b wave were reduced significantly in the sum response.The implicit time of a wave were increased significantly in ring 0 and inferior-nasal quadrant(IN).The implicit time of b wave were increased significantly in ring 0.The overall amplitudes of a wave were reduced significantly in ring 1 and IT. The overall amplitudes of b wave were reduced significantly in ring 0～2 and IT. The response densities of b wave were reduced significantly in ring SN and IT and ST(p<0.05).Conclusion:1.The early changes of retinal function in diabetic eyes with mild NPDR or without retinopathy can be detected objectively and quantitatively by the mf-ERG even before retinopathy.2. The mf-ERG is a sensitive method which can provide evidences and ways for the prevention and cure of diabetic retinopathy.3. FOK response may be more sensitive to SOK response in detecting early diabetic retinopathy.