Lotfi Merabet, OD PhD MPH
Harvard Medical School
Professor of Ophthalmology
Jakobiec Endowed Chair in Ophthalmology, Massachusetts Eye and Ear
Director, The Laboratory for Visual Neuroplasticity, Schepens Eye Research Institute.
Associate Chief of Basic and Translational Research
Co-director of the Center of Excellence for Mobility Enhancement and Vision Rehabilitation.
Staff Optometrist, Vision Rehabilitation Service at Massachusetts Eye and Ear and Spaulding Rehabilitation Hospital.
Biography
Lotfi Merabet is a clinician-scientist investigating how the brain adapts to ocular as well as brain-based visual impairment and blindness. He completed his doctorate in neuroscience (University of Montréal) and clinical doctorate in optometry (New England College of Optometry). He continued his post-doctoral training at Harvard Medical School, Boston University, and the MGH Martinos Center for Biomedical Imaging. This was followed by a master’s degree from the Harvard School of Public Health. He joined the clinical and research faculty of the Massachusetts Eye and Ear in 2010. He also serves on the Education Board of Directors and CVI Steering Committees of the Perkins School for the Blind, the Pediatric Eye Disease Investigator Group (Neuro-ophthalmology Workgroup), and co-chairs the NIH Expert Panel on CVI. His work is currently supported by the NIH/National Eye Institute.
Abstract
Cerebral visual impairment (CVI) is a brain-based visual disorder and the leading cause of pediatric visual impairment in developed countries. Despite this clear public health concern, our understanding of the functional visual profile and underlying neurophysiology of this condition remains poorly understood. In the setting of early neurological injury, children with CVI typically show deficits associated with higher-order visuospatial processing such as finding a target of interest within a complex scene. It remains unknown how manipulating task demands and other environmental factors influence visual search performance in this population. To address this gap, we have developed a series of novel and naturalistic virtual reality (VR)-based visual search tasks combined with eye tracking. We find that CVI is associated with decreased search efficiency and worsening performance with increased visual task demands when compared to neurotypical controls. Combined with neuroimaging modalities, these novel assessments allow for the characterization of the neural correlates associated with visuospatial impairments in CVI. The results may also have important clinical applications in assessing environmental factors that affect functional visual processing in CVI and identifying adaptations that may help performance.