Mapping the Binocular Scotoma in Macular Degeneration Cécile Vullings & Preeti Verghese

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Smith-Kettlewell Eye Research Institute Mapping the binocular scotoma in macular degeneration Cécile Vullings & Preeti Verghese

INTRODUCTION RESULTS When the scotoma is binocular, it often obscures objects of interest, causing individuals with macular degeneration (MD) to miss information. Furthermore, the majority of individuals with MD Coarse-to-fine manual selection of probed locations yields fine details of scotoma edges are unaware of their scotoma, which causes further difficulties in tasks of daily living. 30 B3 Seen (2/2) Here, we propose a method to map precisely the binocular scotoma. 20 Bilateral macular degeneration Missed (0/2) Monocular scotomas (SLO/OCT) Vertically flipped on the retina 10 Partially correct

Seen ﬁeld (deg) ertical visual (1/2) V Missed 0 0 20 40 0 20 40 0 20 40 0 20 40 0 20 40 0 20 40 Fixation Fixation Horizontal visual ﬁeld (deg) Fovea The size and shape of monocular scotoma from the eye-tracker is similar to the SLO map Mapping the blindspot with control participants Mapping the monocular scotoma with B and M participants METHODS C2 B3 Step 1: Screening

Visual acuity - Contrast sensitivity - Stereoacuity - Peripheral retinal loci (SLO) - Extent of monocular scotomas (SLO) - Location of foveal pits (OCT)

Participants: 6 with a binocular scotoma (B; age: 56-89), 3 with monocular scotomas (M; age: 75-79) and 3 controls (C; age: 61-74)

Step 2: Binocular scotoma mapping Eye-tracker SLO Eye-tracker SLO Eye-tracker SLO Eye-tracker SLO

Fixation [450 700] ms The size and shape of binocular scotoma from the eyetracker is similar to the Fixation loci were tightly Stimulus duration 200 ms Maintain fixation + button press estimate from the Ghahghaei-Walker algorithm clustered for all participants Response wait time 2000 ms Fixation [450 700] ms B4 B3 B1 B2 B3 Time Stimulus duration 200 ms Maintain fixation + button press - Eyelink 1000 - 6 sessions, on average - Fixation criterion based on fixation stability - 35 locations probed twice per session - Coarse-to-fine grid to probe visual field (40.36° x 30.27°) Kernel density estimate of fixation distribution M2 M3 Step 3: SLO-based binocular scotoma estimate 1° 5° eeec (Ghahghaei & Walker, 2016) 5° (Crossland et al., 2004)

Left eye (OS) Right eye (OD) Binocular B4 B5 B6 * Monocular map efrom the SLO decentration (deg) Y C2 C1 isual degrees with respect to PRL V 1) The monocular data were modelled using a nearest k (k=10). * Monocular map 5° efrom the SLO

Visual degrees with respect to PRL X decentration (deg)

2) The monocular maps were fitted according a variable threshold (here, t=0.5). CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES Ghahghaei & Walker (2016). SKERI-Optos: A graphical user interface to map - A regular eyetracker can be used to reliably and precisely assess the residual functional retina in We would like to thank Dr. Saeideh Ghahghaei for providing the script of the algorithm from scotoma and PRL with the Optos OCT/SLO. Journal of Vision, 16(4), 40-41. The algorithm uses the perimetry, fixation locus and foveal pit location from the SLO/OCT (21° x Ghahghaei & Walker (2016) and Dr. Don Fletcher for referring the patients who participated in Crossland, Sims, Galbraith & Rubin (2004). Evaluation of a new quantitative binocular vision. technique to assess the number of and extent of preferred retinal loci in macular 21°). The area of the binocular scotoma was estimated by aligning the monocular data on the - Determining the size and location of the binocular scotoma with respect to the fixation locus is key for this study. disease. Vision Research, 44, 1537-1546. foveal pits of each eye. assessing and training an appropriate strategy for eye movements in age-related macular degeneration. This work was supported by a Fulbright grant (CV) and a NIH grant NIH R01 EY029730 (PV). Contact: [email protected]