Remapping the Visual Field to Aid Reading with Central Scotomas

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Project Summary Age-related macular degeneration (AMD) typically produces extensive central vision loss, leading to difficulty in reading, navigating, and other critical tasks. Current assistive devices for vision with central scotomas, while promising, are limited in effectiveness. This proposal aims to fill this gap by advancing understanding of remapping, a method that improves the effectiveness of patients’ residual vision by shifting information from inside the central blind spot (scotoma) to intact locations in the visual field. Only a handful of past studies have examined remapping, including just a single study of patients. Our group recently demonstrated the method’s promise, showing that it can improve reading substantially in observers with simulated field loss. Critically, patients differ widely in the shape of their scotomas, and the quality of their vision across the visual field. This variability imposes severe limitations on the “one size fits all” remapping approaches used in prior work, that simply shift the image away from the scotoma center. If, for example, a patient’s preferred retinal location (used for high acuity tasks) is near the lower left edge of their scotoma, shifting text upward or rightward may not aid reading as much as shifting it downward, as the latter will place the text in regions of best visual acuity. This proposal will test the value of personalized remappings, which shift the image in a way that is optimized for each patient’s residual vision. The remappings are constructed using a novel letter recognition perimetry task, which measures performance across the visual field: The personalized remappings are constructed to shift text to maximize observers’ total letter recognition ability. Proposed work will first test the hypothesis that personalized remapping can improve single word recognition. Single word reading will be measured with a variety of scotoma sizes, shapes, and PRL locations. Performance with personalized remapping will be compared to that with traditional remapping and no remapping in both control observers with simulated scotomas and people with macular degeneration. Proposed work will also test the hypothesis that personalized remappings can improve free reading. Reading speed, error rates, and eye movement patterns will be measured in a sentence reading task, and in free reading of natural images containing text. Preliminary data support the value of remapping generally, and the potential of the letter recognition perimetry task for building personalized remappings. Results of this proposal will provide the first thorough testing of remapping, and will also inform models of peripheral reading in patients and controls. The proposed studies will develop and evaluate a novel method for assisting people with low-visions, tailored to their individual residual performance. Personlaized remapping may also be incorporated into practical visual aids to improve daily visual function and quality of life.