Aim 2 of Reaching with Central Field Loss
Crowding increases with eccentricity, and is most readily observed in the periphery. During natural, active vision however, central vision plays an important role. Measures of critical distance to estimate crowding are difficult in central vision, as these distances are small. Any overlap of...
Walker et al (Renninger, Psomadakis, Dang & Fletcher, 2008) suggested a novel method to estimate the monocular scotoma area from perimetry data in macular degeneration based on (i) an optic-disc based estimation of the location of the fovea and (ii) the increase in the receptive field size with eccentricity. Here, Dr Walker and I introduce a new GUI that applies this method to data from the Optos OCT/SLO. With OCT, it is sometimes possible to locate the foveal pit, giving a better estimation of the fovea. The GUI takes the perimetry, fixation stability and OCT image of each eye as input. It outputs the scotoma area and map relative to the PRL and the estimated fovea. This helps clinicians and researcher to have an objective measure of monocular scotoma and its geometric relation to the PRL and the estimated fovea. The GUI computes BCEA of the PRL and reports the fovea-PRL distance which is valuable information for PRL training. A prediction of the binocular scotoma map/area is computed, assuming that the foveae in the two eyes are aligned. This map informs the user of potential benefits of binocular vision. The GUI has been used by different labs, including ours, at the Smith-Kettlewell Eye Research institute. The GUI is available to the public. A user guide is provided.