Visual exploration of objects and scenes in people with Stargardt disease and macular degeneration

Abstract

Introduction: Lesions of the macula result in loss of central vision and a dependence on low resolution peripheral vision. Most studies in people with central field loss have focused on reading which constitutes the main complaint of patients, though questionnaires of quality of life indicate impairments in daily living activities. Some studies have also reported impairments in face and in object detection or recognition tasks. Little is known about how people with central visual field loss explore realistic images. Methods: We recorded eye movements (scan paths, saccades and fixations) and naming times in patients with juvenile maculopathy (Stargardt disease, mean acuity 1/20), in patients with age related macular degeneration (AMD mean acuity 2.6/10) and in normally sighted age-matched controls (mean acuity 9.1/10). Colored photographs (32.5 X 25.8° of visual angle) of isolated objects, of natural scenes and of objects in scenes were centrally displayed for 2 sec. Eye movements were recorded with an eye tracker (SMI). Results: On average naming accuracy was higher by 30% for controls than for both AMD and Stargardt patients. This difference was equivalent for isolated objects and for objects in scenes. The proportion of fixations in regions of interest was lower in people with maculopathy than in controls. The number of saccades was larger for AMD patients than for Stargardt patients and for controls. Discussion: The results suggest that an abnormal pattern of visual exploration might contribute to deficits in object and scene recognition in both people with Stargardt disease and AMD.

Meeting abstract presented at VSS 2013