Examining the concordance of retinal ganglion cell counts generated using measures of structure and function

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)
67 Downloads (Pure)


Purpose: There are several indirect methods used to estimate retinal ganglion cell (RGC) count in an individual eye, but there is limited information as to the agreement between these methods. In this work, RGC receptive field (RGC-RF) count underlying a spot stimulus (0.43°, Goldmann III) was calculated and compared using three different methods. Methods: RGC-RF count was calculated at a retinal eccentricity of 2.32 mm for 44 healthy adult participants (aged 18–58 years, refractive error −9.75 DS to +1.75 DS) using: (i) functional measures of achromatic peripheral grating resolution acuity (PGRA), (ii) structural measures of RGC-layer thickness (OCT-model, based on the method outlined by Raza and Hood) and (iii) scaling published histology density data to simulate a global expansion in myopia (Histology-Balloon). Results: Whilst average RGC-RF counts from the OCT-model (median 105.3, IQR 99.6–111.0) and the Histology-Balloon model (median 107.5, IQR 97.7–114.6) were similar, PGRA estimates were approximately 65% lower (median 37.7, IQR 33.8–46.0). However, there was poor agreement between all three methods (Bland–Altman 95% limits of agreement; PGRA/OCT: 55.4; PGRA/Histology-Balloon 59.3; OCT/Histology-Balloon: 52.4). High intersubject variability in RGC-RF count was evident using all three methods. Conclusions: The lower PGRA RGC-RF counts may be the result of targeting only a specific subset of functional RGCs, as opposed to the coarser approach of the OCT-model and Histology-Balloon, which include all RGCs, and also likely displaced amacrine cells. In the absence of a ‘ground truth’, direct measure of RGC-RF count, it is not possible to determine which method is most accurate, and each has limitations. However, what is clear is the poor agreement found between the methods prevents direct comparison of RGC-RF counts between studies utilising different methodologies and highlights the need to utilise the same method in longitudinal work.

Original languageEnglish
Pages (from-to)1338-1352
Number of pages15
JournalOphthalmic and Physiological Optics
Issue number6
Early online date6 Sept 2022
Publication statusPublished (in print/issue) - 1 Nov 2022

Bibliographical note

Funding Information:
This work was supported by a PhD studentship from the Department for the Economy, Northern Ireland (VS) and in part by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology (PJM, RSA). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.

Publisher Copyright:
© 2022 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.


  • Retinal Ganglion Cell Count
  • Peripheral Grating Resolution Acuity
  • Structure-Function Relationship
  • peripheral grating resolution acuity
  • structure-function relationship
  • retinal ganglion cell count


Dive into the research topics of 'Examining the concordance of retinal ganglion cell counts generated using measures of structure and function'. Together they form a unique fingerprint.

Cite this