Abnormal Involuntary Eye Movements in the “Lazy Eye” Disease Amblyopia Linked to Changes in Subcortical Regions of the Brain

The neural mechanism underlying amblyopia, also called “lazy eye” is still not completely clear. A new study now reports abnormal eye movements of the lazy eye, which suggests that disturbed functioning of eye movement coordination between both eyes and not primarily the dysfunction of the visual cortex may be a cause of amblyopia (Xue-feng Shi et al.).

Little is known about oculomotor function in amblyopia, or “lazy eye,” despite the special role of eye movements in vision. A group of scientists has discovered that abnormal visual processing and circuitry in the brain have an impact on fixational saccades (FSs), involuntary eye movements that occur during fixation and are important for the maintenance of vision. The results, which raise the question of whether the alterations in FS are the cause or the effect of amblyopia and have implications for amblyopia treatment, are available online in advance of publication in the November issue of Restorative Neurology and Neuroscience.

“Although FSs are of great functional significance in neural coding, visual perception, and visual task execution, their behavioral characteristics in visual and neurological disease have been rarely studied,” says lead investigator Xue-Feng F. Shi, MD, PhD, of the Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, College of Clinical Ophthalmology, Tianjin Medical University, and the Department of Pediatric Ophthalmology and Strabismus, Tianjin Eye Hospital, Tianjin, China. “We carried out quantitative and detailed analysis of fixational saccades in amblyopia for the first time.”