[Subjective detection of visual field defects using the noise-field on a home TV set in low-tension glaucoma]

The usefulness of the Noise-Field Test was studied in 196 normal eyes and 146 eyes of low-tension glaucoma patients (including 74 eyes of early glaucoma) who had never perceived their filed defects. The noise-field spontaneously generated on a 21-inch home television screen through a non-transmitting channel was utilized for the test. A white mark 5 mm in diameter was stuck on the center of the screen as a fixation point. At a distance of 30 cm, the subjects were asked to watch the screen, gazing at the fixation point with one eye for 3-5 seconds, checking to see whether the flickering area on the noise-field diminished or disappeared. The test was performed 3 times on each eye. In 136 glaucoma eyes, the field defects detected by static perimetry (Humphrey) were clearly identified in the Noise-Field Test. In normal eyes, a scotoma was noted on the blind spot in 6 eyes, The sensitivity and specificity was 93.2% and 96.9%, respectively. The Noise-Field Test can be an excellent method in screening for low-tension glaucoma which is easily missed by tonometric screening only.