Event Date
Wednesday, October 25th, 2023 – 12:00pm to 1:00pm
Speaker
Marcello Maniglia, PhD University of California Riverside, US
Host
Senior Scientist Preeti Verghese
Abstract
Macular Degeneration (MD) represents the leading cause of visual impairment in the Western World. Late-stage MD eventually leads to the development of a central region of blindness (scotoma), which compromises their ability to perform everyday life activities like reading and recognizing faces. Patients spontaneously cope with this challenge by adopting compensatory oculomotor strategies, including the development of a new fixation region in their healthy peripheral retina, called Preferred Retinal Locus (PRL), that they use as a functional replacement of the fovea. Given the role of the fovea as a perceptual and oculomotor reference in the healthy visual system, consequences of central vision loss are far-reaching.
Moreover, visual deficits in MD can be extensive yet subjectively subtle, often manifesting as distortions of the visual field or being masked by perceptual filling-in mechanisms. Patients are often unaware of characteristics of their visual deficits. Studies with simulated central vision loss in healthy participants suggest that increased awareness of these deficits could be beneficial for visual rehabilitation.
Hence, it becomes apparent that perception, eye movements and visual field awareness are all altered by loss of central vision. Therefore, characterization of MD and designing of rehabilitative interventions should address the multifaceted nature of this condition.
Here I will present a series of studies investigating perceptual, oculomotor and attentional characteristics of central vision loss, at baseline and after different training interventions. These interventions aimed at improving visual abilities, eye movements and scotoma awareness, in both patients with MD and healthy participants tested with gaze-contingent, simulated scotoma.
Taken together, results suggest that a multidimensional approach to low vision might hold the keys for a better understanding of the effects of central vision loss on perceptual, attentional and oculomotor systems. Furthermore, such approaches might help develop successful interventions for patients with MD.