[Sensitivity and specificity of masked field campimetry]

Patients with circumscribed visual field defects are able to perceive the scotomata immediately while looking at randomly distributed black and white squares (12' x 12') flickering on a VDU with a high frequency (approximately 30 Hz), resulting in a stimulus field comparable to the white-noise field on a TV screen without reception. In 368 eyes of 368 patients with varying lesions of the visual pathway the results of white-noise field campimetry were compared with those of conventional threshold-related, slightly suprathreshold automated grid perimetry. Rate of detection (sensitivity) was 84.2% in conventional perimetry and 80.7% in white-noise field campimetry, respectively. The results are not significantly different (p > 0.1; McNemar test). Examinations in 198 eyes of 198 persons without any indication of a visual pathway defect allowed a definition of the normal range of white-noise field campimetry to be made. The specificity of this new method was 82.3%. The outcome of this most extensive study on sensitivity and specificity of noise field campimetry is compared with other publications. The results presented emphasize the capabilities of this new method as a screening test. They encourage the initiation of a field study using the noise field stimulus broadcasted to home TV sets.