Ageing changes in retinal outer nuclear layer thickness and cone photoreceptor density using adaptive optics-free imaging. Issue 3 (May 2023)

• Record Type: Journal Article
• Authors: Matlach, Juliane; Mulholland, Padraig; Cilkova, Marketa; Chopra, Reena; Shah, Nilpa; Redmond, Tony; Dakin, Steven C; Garway-Heath, David F; Anderson, Roger S
• Is Part Of: European journal of ophthalmology. Volume 33:Issue 3(2023)
• Page Start: 1434
• Page End: 1442
• Publication Date: 2023-05
• Subjects: Cone imaging -- outer nuclear layer -- OCT -- imaging; Ophthalmology -- Periodicals; Eye -- Diseases -- Periodicals; 617.7005
• DOI: 10.1177/11206721221144477
• Languages: English
• ISSNs: 1120-6721

Abstract

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/mm 2 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, R 2 = 0.16 (F(1, 54) = 10.41, P = 0.002); ONL thickness, R 2 = 0.12 (F(1, 54) = 7.41, P = 0.009). No significant association was seen between cone density and ONL thickness (R 2 = 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.