Clinical Ability of High Frequency Pattern VEP and Flicker ERG Examination to Detect Glaucomatous Visual Field Change

PURPOSE: We investigated whether pattern visual evoked potential (VEP) and flicker electroretinogram (ERG) are helpful in detecting the progression of glaucomatous field defect on standard automated perimetry. METHODS: We investigated 50 eyes with primary open-angle glaucoma (POAG) (n=18), glaucoma suspect (n=21), and control (n=11) tested with high frequency pattern VEP and flicker ERG at first visit in our hospital from 1998 to 2002. The results were applied as a prospective study. RESULTS: Thirteen eyes (study group) showed progressive defects, whereas 37 eyes (control group) showed no progression. The hit ratio, sensitivity and specificity were 78.0%, 84.6% and 75.7%, respectively, according to retino-cortical time (RCT) of 88 msec using the receiver operating characteristic curves. The mean survival time for the group with RCT less than 88.0 msec (41.95 months) was longer than that for the group with RCT more than 88.0 msec (31.0 months). The group which had more than 88.0 msec in RCT showed a hazard ratio of glaucomatous field defect progression of 7.855 compared to the other group (RCT: difference between P100 latency in VEP and a wave implicit time in ERG). CONCLUSIONS: Our study showed that high frequency pattern VEP and flicker ERG were significant in the progression of glaucomatous field defect.

Clinical Ability of Heidelberg Retinal Tomograph Examination to Detect Glaucomatous Visual Field Change

PURPOSE: We assessed whether Heidelberg retinal tomograph(HRT)is helpful in predicting the progression of glaucomatous field defect. METHODS: The periodic HRT and visual field results were obtained from 103 patients with primary open angle glaucoma (POAG) or glaucoma suspect who had been in our hospital from 1998 to 2000. Except 45 patients who had undergone ocular operation or had a follow-up of less than 1 year, 58 patients (48 eyes with POAG and 29 eyes with glaucoma) were selected. RESULTS: For glaucoma patients, the sensitivity and specificity to HRT on progression of glaucomatous field defect showed 35.7% and 33.3%, respectively. Their positive predictive value was 78.9%, and negative predictive value 6.9%. According to the results obtained after adjusting the cutoff value of classification score in HRT to -0.32 through the ROC curve, the sensitivity and specificity of progression in the glaucomatous field for glaucoma patients were changed to 57.1% and to 33.3%. Furthermore, the positive predictive value was 86% and the negative predictive value was 10% after the adjustment above. CONCLUSIONS: Our results showed that there was no significant correlation between HRT and progression of glaucomatous field defect in POAG patients or glaucoma suspect patients.