Related Experiment Video
Updated: Aug 15, 2025
Author Spotlight: Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration
Published on: May 26, 2023
Ageing changes in retinal outer nuclear layer thickness and cone photoreceptor density using adaptive optics-free
Juliane Matlach1,2,3, Padraig Mulholland1,4,5, Marketa Cilkova1
1NIHR Biomedical Research Centre, Moorfields Eye Hospital & UCL Institute of Ophthalmology, London, UK.
Purpose:
To investigate age-related changes of the outer nuclear layer (ONL) thickness and cone density, and their associations in healthy participants using a modified, narrow scan-angle Heidelberg Retina Angiograph (HRA2).
Methods:
Retinal cones were imaged outside the fovea at 8.8° eccentricity and cone density was compared to ONL thickness measurements obtained by Spectral-Domain Optical Coherence Tomography (SD-OCT) at the same locations. Fifty-six eyes of 56 healthy participants with a median age (interquartile range, IQR) of 37 years (29-55) were included.
Results:
Median (IQR) cone count was 7,472 (7,188, 7,746) cones/mm2 and median (IQR) ONL thickness was 56 (52, 60) µm for healthy participants. Both cone density and ONL thickness were negatively associated with age: cone density, R2 = 0.16 (F(1,54) = 10.41, P = 0.002); ONL thickness, R2 = 0.12 (F(1,54) = 7.41, P = 0.009). No significant association was seen between cone density and ONL thickness (R2 = 0.03; F(1,54) = 1.66, P = 0.20).
Conclusion:
Cone density was lower, and ONL thinner, in older compared to younger participants, therefore, image-based structural measures should be compared to age-related data. However, cone density and ONL thickness were not strongly associated, indicating that determinants of ONL thickness measurements other than cone density measurements, and including measurement error, have a major influence.
