Age-dependence of the objective optical and mechanical accommodative response measured using a combined dynamic autorefractor and OCT system

Abstract

Purpose : To develop approaches to restore accommodation, research has focused on studying the age-related changes leading to presbyopia. Prior studies have quantified changes in lens shape in response to static accommodative demands, but there is limited data on the relation between lens shape and objective accommodation, and the dynamics of lens shape changes. The goal of this study is to quantify the age-dependence of the optical and biometric accommodative response using a custom-built combined autorefractor and OCT system.

Methods : Accommodative responses of 12 subjects aged 20 to 66 years (mean spherical equivalent refraction −1.67 ± 2.30 D, range -6.25 to 1.75 D) were measured using a device that combined a fixation target providing a controlled ramp accommodation stimulus, wavefront-based autorefractor, and an extended-depth OCT system that acquires images of the anterior segment and lens. Subjects were presented with a 12 D ramp stimulus at a speed of 0.5 D/s. Wavefront measurements and cross-sectional OCT images were acquired sequentially in real-time during the ramp at 33 Hz and 4.7 frames/s, respectively. Three runs were performed on each subject. Lens thickness was quantified from the OCT images using a semi-automatic segmentation software. The following parameters were quantified versus age: maximal accommodation, lens thickness change, accommodation response vs stimulus, lens thickness per D stimulus, and the relation between lens thickness change and optical accommodative response.

Results : Refraction and lens thickness varied linearly with stimulus. The optical response to a given stimulus decreased with age at a rate of 0.023 D/D/year. (Figure 1C) There was no statistically significant age-dependence of the change in lens thickness per Diopter of accommodative response in pre-presbyopic eyes (Age <50 years, average: 0.032 mm/D). (Figure 1D)

Conclusions : The decrease in accommodative gain (response/stimulus) combined with constancy of the lens thickness per Diopter response lends further support to the theory that attributes presbyopia to age-related changes in the ability of the lens to change shape.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Figure 1: AR-OCT OCT data (12 D ramp stimulus, 0.5 D/s). A) Maximal accommodation vs age, B) lens thickness change vs age, C) accommodation response per D stimulus vs age, and D) thickness change per D of accommodation vs age.