Association Between Aging and Dark Adaptation Measured with an Augmented Reality Head-Mounted Device

Abstract

Purpose : To assess the correlation of age with the capacity to adapt to darkness on normal subjects using a modified augmented reality head-mounted device (HMD).

Methods : Ninety-six healthy subjects aged 19 to 85 had their dark adaptation (DA) tested using the HMD. Participants with ocular conditions that could impact DA, such as age-related macular degeneration, were excluded from the study. Heru re:Vive software (Heru, Inc., Miami, FL) was used within a Magic Leap 1 (Magic Leap, Plantation, FL) device, which was modified with a light shield and neutral density filter to create a dark testing environment, and a dark adaptation accessory system (DAAS) to administer the flashes. The subject’s spherical equivalent distance correction was applied. The subject underwent two calibration steps. The first was for fixation monitoring, and the second ensured proper bleaching of the desired location of the retina. The DAAS administered the appropriate number of flashes dependent on the measured pupil size. The subject was then shown stimuli in the bleached region of varying brightness until a threshold measurement was obtained. The generated test reports include a plot of the measured sensitivity thresholds over time and a DA index (DAI) calculated as the ratio of the mean threshold between 3 and 4 minutes to the mid-point between that time interval.

Results : Figure 1 demonstrates a significant decrease in the DAI with increasing age, with an average reduction of 0.00353 in the DAI per year (R= -0.416, 95% CI: -0.212 to -0.620, p <0.0001, Pearson correlation). This indicates that the DA function deteriorates with age. Statistical testing of age group differences (Group 1: <60, Group 2: ≥60) showed that the DAI was significantly different between the two groups (p<0.0001, Mann Whitney U test), with noticeably lower DAI values in the older (Group 2) (median DAI = 0.7229) compared to the younger (Group 1) (median DAI = 0.7886).

Conclusions : Our results show that DA functions significantly decrease after age 60, consistent with prior studies. Further research is needed to distinguish between the expected effects of aging and those of other eye diseases on DA.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.