A saccadic choice task for target face detection at large visual eccentricities in patients with glaucoma
Résumé
Significance: Little is known about the perception of glaucomatous patients at large visual eccentricities. We show that the patients' performance drops beyond 40° eccentricity even for large images of scenes suggesting that clinical tests should assess the patients' vision at larger eccentricities than 24 or 30°. Purpose: Daily activities such as visual search, spatial navigation and hazard detection require rapid scene recognition on a wide field of view. We examined whether participants with visual field loss at standard automated perimetry 30-2 were able to detect target faces at large visual eccentricities. Methods: Twelve patients with glaucoma and 14 controls were asked to detect a face in a two-alternative saccadic forced choice task. Pairs of scenes, one containing a face, were randomly displayed at 10, 20, 40, 60 or 80° eccentricity on a panoramic screen covering 180° horizontally. Participants were asked to detect and to saccade towards the scene containing a face. Results: Saccade latencies were significantly slower in patients (264ms, CI: 222 to 306ms) than in controls (207ms CI: 190 to 226ms) and accuracy was significantly lower in patients (70% CI: 75% to 85%) than in controls (75.7% CI : 71.5% to 79.5%). Though still significantly above chance at 60°, the patients' performance dropped beyond 40° eccentricity. The controls' performance was still above chance at 80° eccentricity. Conclusions: In patients with various degrees of peripheral visual field defect, performance dropped beyond 40° eccentricity for large images at a high contrast. This result could reflect reduced spread of exploration in glaucoma.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)