Novel methods to assess ocular motor behavior of patients with amblyopia

Amblyopia occurs in 3 – 5% of the population and is defined as a unilateral or bilateral loss of vision resulting from abnormal visual stimulation during the early years of visual development. In clinics, the diagnosis of amblyopia largely relies on a decreased monocular or binocular visual acuity, the absence of any pathology that would explain the visual deficit, and the presence of an amblyogenic factor (usually strabismus or anisometropia). However, several other visual functions such as contrast sensitivity, stereopsis, eye movements or visual processing are also affected in amblyopia. This work is focused on the effects of amblyopia on eye movements. There are extensive research studies which have reported ocular motor deficits in the amblyopic and fellow eyes, such as longer saccadic latencies and reduced saccadic amplitudes, low pursuit gain, or fixation instability. These studies have been done in very controlled laboratory conditions, presenting visual stimuli on a computer screen and recording eye movements with an eye-tracker. Although these findings are relevant in the context of basic research on the neural mechanisms of amblyopia, the consequences of these ocular motor deficits in daily life are unknown. In this work, eye movements of children with amblyopia will be measured with a portable eye-tracker while they do naturalistic tasks which require a combination of visuospatial abilities. Their ocular motor behavior will be compared to that of age-matched typically developing children to determine how amblyopia affects their performance in daily life activities. This work is part of a bigger project that the research group VISPEC (Visual Optics and Spectral Imaging Group) from the CD6 (Centre for Sensors, Instruments and Systems Development) is carrying out at the moment.