title: Binocular glaucomatous visual field loss and its impact on visual exploration--a supermarket study.
abstract: Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i) assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii) to identify factors influencing the performance, and (iii) to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP), and ten healthy-sighted control subjects (GC) were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as "passed" or "failed" with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item). Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s) to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p < 0.001). Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD) area than patients who failed (t-test, p < 0.05). According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a "time-effective" compensatory mechanism during the present supermarket task.
authors.affiliation: Computer Engineering Department, University of Tübingen, Tübingen, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Sippel
authors.affiliation: Computer Engineering Department, University of Tübingen, Tübingen, Germany.
authors.forename: Enkelejda
authors.initials: E
authors.lastname: Kasneci
authors.affiliation: Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Aehling
authors.affiliation: Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Heister
authors.affiliation: Computer Engineering Department, University of Tübingen, Tübingen, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rosenstiel
authors.affiliation: Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Competence Centre "Vision Research", Study Course "Ophthalmic Optics/Audiology", University of Applied Sciences Aalen, Aalen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schiefer
authors.affiliation: Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Department of Ophthalmology, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Elena
authors.initials: E
authors.lastname: Papageorgiou
mesh_terms: D000203:Activities of Daily Living; D000222:Adaptation, Physiological; D000368:Aged; D016022:Case-Control Studies; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010364:Pattern Recognition, Visual / Q000502:physiology; D011788:Quality of Life; D011930:Reaction Time; D012607:Scotoma / Q000503:physiopathology*; D013647:Task Performance and Analysis; D014785:Vision, Ocular / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields