Extracting spacing-derived estimates of rod density in healthy retinae

Heather Heitkotter; Emily J Patterson; Erica N Woertz; Jenna A Cava; Mina Gaffney; Iniya Adhan; Johnny Tam; Robert F Cooper; Joseph Carroll

doi:10.1364/BOE.473101

Extracting spacing-derived estimates of rod density in healthy retinae

Biomed Opt Express. 2022 Dec 5;14(1):1-17. doi: 10.1364/BOE.473101. eCollection 2023 Jan 1.

Authors

Heather Heitkotter^{1

2}, Emily J Patterson^{3

2}, Erica N Woertz⁴, Jenna A Cava⁵, Mina Gaffney⁶, Iniya Adhan⁷, Johnny Tam⁸, Robert F Cooper^{5

6}, Joseph Carroll^{1

5

6}

Affiliations

¹ Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.
² These authors contributed equally to this work.
³ UCL Institute of Ophthalmology, University College London, London, UK.
⁴ John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.
⁵ Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.
⁶ Joint Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, USA.
⁷ School of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
⁸ National Eye Institute, National Institutes of Health, Bethesda, MD, USA.

Abstract

Quantification of the rod photoreceptor mosaic using adaptive optics scanning light ophthalmoscopy (AOSLO) remains challenging. Here we demonstrate a method for deriving estimates of rod density and rod:cone ratio based on measures of rod spacing, cone numerosity, and cone inner segment area. Twenty-two AOSLO images with complete rod visualization were used to validate this spacing-derived method for estimating density. The method was then used to estimate rod metrics in an additional 105 images without complete rod visualization. The spacing-derived rod mosaic metrics were comparable to published data from histology. This method could be leveraged to develop large normative databases of rod mosaic metrics, though limitations persist with intergrader variability in assessing cone area and numerosity.

Abstract

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