advertisement
Abstract #13598 Published in IGR 8-2
Multifocal visual evoked potential in normal eyes and the primary glaucoma
Dong X-F; Wang P-B; Xia Z-H; Tan Q; Xia X-B; Huang P-GInternational Journal of Ophthalmology 2006; 6: 110-113
AIM: To study the characteristic of the normal multifocal visual evoked potential (mfVEP) and to test the ability of mfVEP in detecting glaucoma using the mfVEP from normal is subjects, glaucomatous patients. METHODS: mfVEPs of 32 normal eyes (n = 21) and 58 eyes (n = 37) with pr imary glaucoma were recorded with the Vision Monitor electrophysical apparatus by the second kernel analysis. Humphrey automated visual fields (HVF) were also obtained from the eyes with glaucoma to determine the correlation between them. RESULTS: 1. The study showed that signals in the center zone of the normal had the largest amplitudes (194.32 ± 126.21nV/deg2 ). There was little effect of age on the amplitudes and latent time and no difference was found between the two eyes, while the amplitudes of female (19.41 ± 5.27 nV/deg2 ) were larger than that of the male (10.12 ± 2.83 nV/deg2 ) (P < 0.05); 2. There was significant interindividual variability (the coefficient of variation was 43.05%) in mfVEP amplitudes in the normal subjects but the variability within two eyes of the same individual was small; 3. The amplitudes of eyes with glaucoma were smaller than that of the normal eyes and significantly statistical difference were found in the 0-10° ring zone (P < 0. 05) while no difference of the latent time was observed between them; 4. If the two eyes of one patient with glaucoma were damaged to the same extent, the amplitudes of the two eyes were almost the same; while not to the same extent the amplitudes were different. 5. The summation values of mfVEP amplitudes and HVF mean deviation values was strongly correlated (rs = -0.487, P = 0.000). The established glaucoma eyes with field defect were also confirmed in the mfVEP and the correlation of the topographic location was good. CONCLUSION: The large individual variability of mfVEP responses limits the detecting of the early field defect by the simple signal comparison between the normal subjects and the patients with glaucoma. By using intereye asymmetry analysis the early visual field defect may be detected as for the damages within the two eyes are not the same or only one eye is damaged. The measurement is not applicable to both eyes damaged to the same extent. For the established glaucomatous eyes, the amplitudes of the mfVEP descend and has a strong correlation with the MD value, which to some extent may offset the shortage of the automated visual field. LA: Chinese
Dr. P.-B. Wang, Department of Ophthalmology, Xiangya Hospital, Central-South University, Changsha 410008 Hunan Province, China
Classification:
6.7 Electro-ophthalmodiagnosis (Part of: 6 Clinical examination methods)
