Purchase this article with an account.
P Thienprasiddhi, VC Greenstein, C Chen, EZ Karam, JM Liebmann, R Ritch, DC Hood; Multifocal VEP Responses in Glaucoma Patients With Unilateral Hemifield Defects . Invest. Ophthalmol. Vis. Sci. 2002;43(13):2180.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To determine whether the multifocal visual evoked potential (mfVEP) technique can detect damage in the unaffected normal hemifields of glaucoma patients with unilateral hemifield defects, as defined by HVF 24-2. Methods: mfVEPs were obtained from 30 control subjects and 10 patients with open-angle glaucoma (OAG). The patients with OAG had unilateral hemifield defects, based on the HVF 24-2. HVF hemifields were considered abnormal if 2 or more adjacent points in the total deviation probability plot exceeded 1%, or 3 or more adjacent points exceeded 5%. The difference between the HVF total deviation values for two eyes (diffHVF) was calculated and compared to the normal data. From this a probability plot was obtained . Monocular mfVEPs were obtained from each eye using a pattern-reversal dartboard array with 60 sectors, the diameter of the display was 44.5 deg. The electrodes were placed at the inion (I), 4 cm above I, and 1 cm above and 4 cm either to the left or right side of I. An interocular mfVEP ratio [RMS amplitude(OD)/RMS amplitude(OS)] was obtained for each pair of responses. These ratios were compared to those from the control group, and a probability plot similar to that of the HVF was obtained [2,3]. The diffHVF and mfVEP hemifields were considered abnormal if 2 or more adjacent points exceeded 3SD, or 3 or more adjacent points exceeded 2SD. Results: None of the 30 control subjects had mfVEP hemifields defined as abnormal by our criteria. All OAG patients had abnormal mfVEPs in the hemifields defined as abnormal by HVF 24-2. In the patients’ unaffected hemifields (defined by HVF), 4 of the 10 patients had abnormal mfVEPs. With the diffHVF, 4 patients showed an abnormality in the unaffected hemifields as defined by HVF, 2 of these patients also had abnormal mfVEPs. Conclusion: The mfVEP is able to detect visual field defects in glaucoma patients [3,4]. Defects can be detected with the mfVEP in areas with normal perimetry results. 1. Johnson & Fry (1999) ARVO 2. Hood et al, (in press) Doc Oph 3. Hood et al (2000), IOVS 4. Graham et al (2000), J Glau. CR: None. Support: NIH/NEI grant EY02115.
This PDF is available to Subscribers Only