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Titolo:
Parallel pathways, noise masking and glaucoma detection: behavioral and electrophysiological measures
Autore:
Yates, JT; Leys, MJ; Green, M; Huang, W; Charlton, J; Reed, J; Di, BZ; Odom, JV;
Indirizzi:
W Virginia Univ, Robert C Byrd Hlth Sci Ctr, Dept Ophthalmol, Morgantown, WV 26506 USA W Virginia Univ Morgantown WV USA 26506 thalmol, Morgantown, WV 26506 USA AL AOCOC, Brooks AFB, TX USA AL AOCOC Brooks AFB TX USAAL AOCOC, Brooks AFB, TX USA
Titolo Testata:
DOCUMENTA OPHTHALMOLOGICA
fascicolo: 3-4, volume: 95, anno: 1998,
pagine: 283 - 299
SICI:
0012-4486(1998)95:3-4<283:PPNMAG>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
OPEN-ANGLE GLAUCOMA; OPTIC-NERVE FIBERS; CONTRAST DISCRIMINATION; OCULAR HYPERTENSION; EFFICIENCY; PERIMETRY; DENSITY; COLOR; AGE;
Keywords:
early detection; glaucoma; ideal observer; magneocellular pathway; noise; parallel pathways; parvocellular pathway; signal detection theory;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Odom, JV W Virginia Univ, Robert C Byrd Hlth Sci Ctr, Dept Ophthalmol, POB9193, Morgantown, WV 26506 USA W Virginia Univ POB 9193 Morgantown WV USA 26506 wn, WV 26506 USA
Citazione:
J.T. Yates et al., "Parallel pathways, noise masking and glaucoma detection: behavioral and electrophysiological measures", DOC OPHTHAL, 95(3-4), 1998, pp. 283-299

Abstract

Purpose: We tested the hypothesis that because of their reduced neural efficiency, glaucoma patients should have increasingly impaired thresholds as external noise is added to a stimulus. Method: We compared the performance of 20 normals (mean age = 39 years) with that of 15 patients with early glaucoma or at very high risk for glaucoma (mean age 45 years). All patients had normal visual acuity. Contrast thresholds were measured on two sets of tasks: (1) behavioral and (2) sweep visually evoked potentials (VEPs). Two stimuli were used (a) 7.5 Hz reversing gratings of 0.69 cpd, and (b) 5.5 cpdgratings. Noise was binary and contrast varied from 0 to 80%. Psychophysical thresholds were determined using a staircase which employed a spatial four alternative forced choice procedure (4AFC) and converged on 50% correct. Sweep VEP thresholds were determined by extrapolation to zero volts as a function of log contrast. Results: Differences between normal subjects and patie nts with early glaucoma were not significant without noise. Both the absolute size of the difference and its significance increased as noise level increased. For the behavioral thresholds these trends were clearer with the 5.5 cpd grating, while for the sweep VEPs they were more clear for the 0.69 cpd grating. Conclusion: The performance deficit of glaucoma patients which may be minimal under normal testing conditions is magnified when external noise is added to the stimulus. VEPs and psychophysical thresholds showinteresting differences in their sensitivity to this effect. Implications for the early detection of glaucoma are discussed.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 14/07/20 alle ore 08:57:38