Neurophysiology of visual system development

Research

The research group aims at studying the neurophysiological basis of the visual system development, with a focus on amblyopia and strabismus.

Amblyopia is caused by a mismatch between the images sent to the visual cortex by each eye during the critical period of the visual system development (i.e., before 7 or 10 years old, depending on the studies). This mismatch derives from strabismus, anisometropia, or an organic cause, such as ptosis or congenital cataract.

Amblyopia causes suppression of the non-dominant eye, a decreased visual acuity in the suppressed eye, and an altered binocular vision. Thus, amblyopia is associated with an abnormal functioning of the ventral pathway resulting in low reading performance, among other visual deficits. The dorsal pathway is also affected, leading to difficulties in visuomotor skills, such as grasping or balance.

Strabismus generally derives from an abnormal neuromuscular control of eye movements. It may be caused by nerve palsies or abnormalities, such as in the Duane retraction syndrome. This syndrome has been described as the consequence of a congenital anomaly of the 6th cranial nerve nuclei with aberrant innervation by supply from the 3rd cranial nerve.

Research topics of the group include (i) analysis of the extent to which the ventral and dorsal pathways are affected in amblyopia, (ii) the differences in the alteration patterns according to amblyopia etiologies, and (iii) the neuroanatomic correlates of these patterns. The study of the dorsal pathway includes a variety of clinical topics, particularly the analysis of saccades and pursuit in the Duane retraction syndrome and in amblyopia.

Ongoing projects:

  • Anatomic lesions in amblyopic populations at the level of the retina and the brain
  • Face and word recognition in control and amblyopic populations
  • Oculomotor control of saccades and pursuit in amblyopic patients
  • Spontaneous consecutive exotropia following childhood esotropia
  • Recurrence after surgical management of exotropia