PATTERN ELECTRORETINOGRAM AND PERIPHERAL COLOR CONTRAST THRESHOLDS INOCULAR HYPERTENSION AND GLAUCOMA - COMPARISON AND CORRELATION OF RESULTS

Aims-Both pattern electroretinogram and peripheral colour contrast thr esholds have been shown to be abnormal in glaucoma and ocular hyperten sion. This study evaluates each of these tests as tools for the early diagnosis of glaucoma, compares and contrasts the results, and examine s the relation between the two tests in a large cohort of ocular hyper tensive patients. Methods-Transient and steady state pattern electrore tinograms and peripheral colour contrast thresholds were performed in 45 normal, 37 glaucomatous, and 206 ocular hypertensive eyes. The resu lts were analysed using receiver operating characteristic curves, toge ther with evaluation of sensitivity and specificity of the tests. The relation between the two tests was examined by direct statistical corr elation of the results. Results-All tests showed high sensitivity and specificity for discriminating between normal and glaucomatous eyes. H owever, there was a significant difference between the two tests for t he number of ocular hypertensives considered as abnormal. Forty per ce nt of ocular hypertensives had abnormal pattern electroretinogram comp ared with 30% with abnormal peripheral colour vision. Peripheral colou r contrast thresholds showed a significant correlation with both trans ient and steady state pattern electroretinogram. Conclusion-Both of th ese tests have been shown to be promising new tools for the early dete ction of glaucoma but the number of ocular hypertensive patients showi ng abnormal results is rather higher than expected considering the nat ural history of the condition. Sensitivity in ocular hypertension may be increased by using a combination of both tests. The significant cor relation between these psychophysical and electrophysiological tests i s discussed.