Instrumental activities of daily life in individuals with central visual field loss

Abstract

Introduction: Previous publications on quality of life in patients with age-related macular degeneration (AMD) report difficulties in performing vision-related daily tasks, such as reading, writing, and cooking, leading to a progressive loss of independence and decreased related functions. Patients with AMD also encounter more difficulties than do age-matched normally sighted individuals finding objects under crowded conditions. Studies on visual perception in central vision loss pathologies typically use 2D images of objects. However, images differ from the natural world in several ways, including the nature of the visual stimulus and the role of task demands. Our study assessed the ability of patients with AMD to accomplish a sequence of realistic actions using the eye movement technique. Methods: We monitored eye movements in 16 subjects with AMD and 16 age-matched normally sighted participants under two realistic active viewing conditions. Participants wore a head-mounted eye tracker, and were seated in front of a table with the objects required for accomplishing a familiar task (sandwich-making) and an unfamiliar task (model-building). The scenes contained both task-relevant and task-irrelevant objects. Temporal and spatial characteristics of gaze were compared for each group and task. Results: The results show that patients were able to perform both familiar and unfamiliar tasks, though patients were twice as slow, and less accurate than controls to copy the display model in the unfamiliar task. Patients exhibited longer gaze durations than controls on irrelevant objects in both tasks. They also looked longer at task-relevant objects and needed to manipulate the objects more in order to identify them. Although patients tended to place the task-relevant regions on a similar retinal location, there was no well-defined PRL (Preferred Retinal Locus). Conclusion: People with AMD exhibit difficulties in realistic actions but seem to establish compensatory strategies (e.g., object manipulation) to accomplish the task.

Meeting abstract presented at VSS 2013