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Abstract #9213 Published in IGR 5-2
Multifocal visual evoked potential responses in glaucoma patients with unilateral hemifield defects
Thienprasiddhi P; Greenstein VC; Chen CS; Liebmann JM; Ritch R; Hood DCAmerican Journal of Ophthalmology 2003; 136: 34-40
PURPOSE: To determine whether the multifocal visual evoked potential (mfVEP) technique can detect damage to the visual system in the unaffected hemifields of patients with glaucoma and unilateral hemifield defects. DESIGN: Experimental study. METHODS: Monocular mfVEPs and achromatic automated perimetry (AAP) were obtained in both eyes of 16 patients with open-angle glaucoma and unilateral hemifield defects. The mfVEPs were obtained using a pattern-reversal dartboard array with 60 sectors; the entire display was 44.5° in diameter. For each pair of mfVEP responses an interocular ratio of root-mean-square amplitude was calculated. These values were compared with the mean values obtained from 30 control subjects. Probability plots for MfVEP were derived. A cluster analysis was used to determine whether an mfVEP hemifield was normal or abnormal. RESULTS: Three of 60 (5.0%) mfVEP hemifields from control subjects had significant mfVEP deficits based upon a cluster of abnormal points. Significant mfVEP deficits were detected in the affected AAP hemifield in 15 of 16 (93.8%) glaucoma patients and in six of 16 patients in hemifields with apparently normal AAP. The percentage of hemifields with abnormal mfVEPs, but normal AAP, was significantly higher for the glaucoma patients than for the controls (37.5 versus 5.0%, p < 0.001, Χ2). In glaucomatous eyes with achromatic visual fields defects limited to one hemifield, the mfVEP technique can detect evidence of glaucomatous damage in the unaffected hemifield.
Dr. P. Thienprasiddhi, Department of Ophthalmology, The New York Eye and Ear Infirmary, New York, NY 10003, USA
Classification:
6.7 Electro-ophthalmodiagnosis (Part of: 6 Clinical examination methods)
