[White-noise field campimetry before and after artificial increase of intraocular pressure. Possible applications in diagnosis and evaluation of glaucoma].

A total of 173 eyes (visual field defect stages O-V) of 99 glaucoma patients were investigated by means of conventional threshold-oriented suprathreshold automated test point perimetry using the Tübingen Automatic Perimeter (TAP) and by means of white-noise-field campimetry (flickering random dot pattern) using the Tübingen Electronic Campimeter (TEC). Most eyes were affected by primary open-angle glaucoma (119) or low tension glaucoma (35). The concordance between the two methods was good in 65 eyes (37.6%). Sufficient in 32 (18.5%) eyes, poor in 32 cases (18.5%) and inadequate in 44 eyes (25.4%). Among the last group of 44 eyes, 32 perceived a scotoma in the noise field (NF) but did not show any pathologic defect in conventional automated test point perimetry: the opposite constellation was found in only 12 eyes. In most cases, scotoma in the NF showed a change in both brightness and motion (noise) perception. No clear relationship between the type of glaucoma and a certain constellation of the aforementioned NF specifications could be found. Complete lack of noise perception in the scotoma occurred more frequently in advanced glaucoma (stage > or = IV). In 110 eyes of 63 of the glaucoma patients, white-noise-field campimetry was carried out during artificial IOP elevation achieved by suction-cup oculopression: during steplike increases of the negative pressure in the suction-cup up to maximum of 375 mmHg the following stages could be seen (the percentage of eyes that perceived each phenomena over the negative pressure range is shown in brackets): change in NF perception compared with initial findings (96.4%); impairment of central noise-field perception (78.2%); concentric constriction of NF (61.8%); complete breakdown of noise (field) perception (42.7%). A further, quantitative classification of these eyes was possible by evaluation of the negative pressure in the suction-cup that led to any one of these NF phenomena. The results demonstrate the usefulness of white-noise-field campimetry as a very fast screening method for detecting glaucomatous visual field defects. It can also be performed as a pressure tolerance test and thus be used to classify glaucomatous risk stages.