Abstract
Purpose:
To observe the characteristics of electrophysiology in Chinese patients with leber’s hereditary optic neuropathy(LHON) .
Methods:
Twelve patients with the mean age of 28 year-old (range from 13 to 59) were diagnosed as LHON by mitochondrial DNA test. We compared the electrophysiology test results of these subjects to normal value.
Results:
Eight patients had the Flash Visual Evoked potential(FVEP) and implicit time of P2 wave were all within the normal range. Seven patients had the Pattern Visual Evoked Potential and 4 of them showed mildly prolonged P100 implicit time, 3 had moderately prolonged P100 implicit time. Nine patients had Pattern Electroretinogram (PERG) test and 6 of them showed reduced value of N95/P50 in both eyes while the P50 amplitude were normal. Nine patients had the Flash Electroretinogram(FERG) and the results were all normal. Eight patients had Multifocal Electroretinogram (mfERG) and six of them manifested the decrease of amplitude density within 10°of macula area while higher amplitude between 10° to 30°. Two patients had reduced amplitude density of the whole 30°of macular area. OCT in eight patients showed decreased ganglion cells and IPL complex layer in macular and retinal nerve fiber layer (RNFL) around optic disc. Eight patients had the Visual Field (VF) test and the VFs demonstrate visual field defect around blind spot. After the treatment of idebenone and coenzyme Q, two eyes of two patients showed mild improvement in BCVA, PVEP implicit time and mfERG amplitude density.
Conclusions:
In these LHON patients, the decrease of N95/P50 ratio in PERG showed the damage of ganglion cells, which was confirmed by the structural loss by OCT in macular ganglion cells layer and RNFL around optic nerve head. mfERG showed impaired retinal function in macula area. The latency time of FVEP usually did not delay but the PVEP showed mild prolonged P100 implicit time.