Abstract
Purpose :
Recently, optical coherence elastography (OCE) was shown to be able to record the axial strain map in the human lens while undergoing microfluctuations associated with accommodation (MFs) in vivo. Here, we investigate the role of accommodation demand on the amplitude of MFs and their changes with age using a standard OCT system.
Methods :
Six participants, aged 24 to 54 years, were exposed to three successive accommodative stimuli: 0D, -2D, -4D. While focusing on a visual target positioned in line with the OCE system. A total of 128 consecutive spectral domain OCT B-scans were acquired during 4 seconds. Phase-sensitive processing was performed to quantify the axial strain induced between subsequent B-scans. Semi-automatic segmentation was performed to determine the lens thickness. A frequency analysis of the axial strain and thickness changes was also performed.
Results :
The average dominant frequency of MFs was 0.34 Hz. There was a significant correlation between the maximum axial strain amplitude of the MFs and both, the accommodation stimulus (r=-0.44, P=0.04) and age (r=-0.72, p<0.001). Similarly, the amplitude of macroscopic thickness variations during MFs correlated with age (r=-0.70, p<0.001). Multiple regression showed that MF strain amplitude decreases with age by -0.041 ‰/year (p<0.001) and increases with accommodative demand by 0.205 ‰/D (p=0.006). As expected, in participants of ≤45 years, the highest strains during MFs were observed in the lens nucleus and not in the lens cortex.
Conclusions :
OCE enables the quantification of the internal strain pattern that occurs during MFs with high spatial resolution, opening the possibility of investigating their role in accommodation and using this measurement as a tool to assess biological age.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.