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Updated: Jun 16, 2026
A Workflow to Quantitatively Determine Age-Related Macular Degeneration Lesion-Specific Variations in Fundus Autofluorescence
Published on: May 26, 2023
Concept of a functional retinal locus in age-related macular degeneration
Noburu Shima1, Samuel N Markowitz, Sophia V Reyes
1Low Vision Service (University Health Network Hospitals), Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.
Purpose:
Preferred retinal loci used for eccentric fixation in patients with age-related macular degeneration (AMD) may be different from the eccentric neighbouring loci of highest retinal sensitivity. This study was designed to highlight the conceptual difference between the 2 and the concept of a functional retinal locus encompassing both the preferred retinal locus and the locus with highest retinal sensitivity.
Design:
Prospective, nonrandomized, observational case series.
Participants:
We recruited 15 adults with documented AMD, low vision, and best-corrected visual acuity of 20/50-20/400 in the better eye.
Methods:
Automated microperimetry methods were used to assess topographic retinal sensitivity and location of preferred retinal loci.
Results:
Mean (SD) age for the group was 85.1 (6.5) years. Mean (SD) best-corrected visual acuity measured was 0.88 (0.25) logMar units (20/150). The mean (SD) eccentricity of the preferred retinal locus used for fixation was different from the eccentricity of the area with highest retinal sensitivity in the same eye (7.53 degrees [2.47 degrees ] vs 9.30 degrees [2.93 degrees ], respectively; p < 0.0003). The oculomotor efficiency score measured 82%. The mean (SD) retinal sensitivity at the preferred retinal loci was inferior to that of loci with highest retinal sensitivity (5.83 [4.26] vs 8.60 [3.06] dB, respectively; p < 0.0007). The highest correlation was measured between potential visual acuity estimates and estimates of retinal sensitivity at the highest retinal sensitivity loci (p < 0.0048).
Conclusions:
Preferred retinal loci and highest retinal sensitivity loci are not identical in AMD cases. A new concept of functional retinal locus is proposed to define their relation. A new concept of an oculomotor efficiency score is proposed to define oculomotor abilities when macular function is lost.
