Visual exploration of objects and scenes in patients with age-related macular degeneration

Abstract

Objective: Studies on people with age-related macular degeneration (AMD) have shown that they are able to detect briefly displayed objects and scenes with high accuracy (above 80%). However, in everyday life we explore our environment to search and to recognize objects. We assessed visual exploration in people with AMD during the identification of objects and scenes.

Method: Twenty patients with AMD, fifteen age-matched and twelve young controls participated. We used colored photographs of isolated objects, natural scenes and objects in scenes, displayed centrally on a monitor. Participants were asked to name the objects and scenes. Ocular movements were recorded during the identification task. Scan paths, saccades, fixations, and accuracy were also recorded.

Results: People with AMD exhibited lower accuracy (by about 30%). Eye movement parameters were impaired with a larger number of saccades, shorter fixation durations and a larger scan path than controls.

Conclusions: Our results are consistent with studies on artificial scotoma in normally sighted people showing that a central scotoma impairs oculomotricity. In contrast to detection tasks, people with central vision loss exhibit impaired performance in identification of objects and scenes (62 to 66%). Eye movement studies suggest that the lower accuracy in patients is likely due to the use of peripheral vision and instability of fixation.

Keywords: Basse vision; Central scotoma; Dégénérescence maculaire; Eye movement; Low vision; Macular degeneration; Mouvement oculaire; Object recognition; Reconnaissance des objets; Scene; Scotome central; Scène.