Behavioral and oculomotor effects of scotoma awareness training in patients with central vision loss

Macular degeneration (MD), a pathology affecting central vision, is the primary cause of visual impairment in the Western world. Late-stage MD leads to blind spots in the central portion of the visual field (scotomas). Loss of central vision significantly hampers patients' daily activities, compromising their quality of life. MD patients spontaneously adapt to this condition by developing compensatory oculomotor strategies, with the most common being the adoption of a Preferred Retinal Locus (PRL), a peripheral region substituting for the fovea. However, time course of PRL development is often suboptimal, taking up to months, with some patients failing at developing one at all. Some visual rehabilitation interventions teach patients to develop and maintain a PRL; however, these protocols encounter challenges. MD patients are often unaware of the size, location, and shape of their scotoma, thereby hindering visual training outcomes. To better understand what training approaches may be efficacious, several studies have employed real-time eyetracking to simulate central vision loss as a model system for the study of compensatory oculomotor strategies in MD. This research showed that eye movement behaviors observed in MD, such as PRL development, can be observed in simulation of central vision loss as well. Importantly, these behaviors emerge after few hours of training, unlike the months usually required in patients, possibly due to the hard-edged, gaze-contingent occluder. Here, we investigated whether using gaze-contingent displays to help patients visualize the retinal scotoma on a computer screen in real-time while performing 10 sessions of a visual discrimination task, would increase scotoma awareness and promote rapid PRL development. We will present and discuss preliminary results from this scotoma awareness group compared to the same training in participants without the visualization of the scotoma, including PRL development and location across training sessions, and behavioral outcomes, such as reading speed and visual acuity.