Abstract
Purpose :
Recent contrast sensitivity (CS) studies have shown that CS can discriminate AMD disease severity and that it is associated with quality-of-life in patients with AMD. The purpose of this study was to test the usability and compare the contrast sensitivity function (CSF) measured among AMD disease groups using a novel contrast testing approach based in a virtual reality (VR) headset.
Methods :
Prospective cross-sectional observational study enrolled patients with AMD (exudative or non-exudative) between June 2023 to October 2023. CSF testing based on a radial sweep test was performed in each eye under mesopic conditions using a prototype gaze tracking-based VR headset (Varjo Aero, Varjo Helsinki, Finland). The radial sweep test presents to the test eye multiple moving circular patches of different contrast and spatial frequencies (PMID 33369613). The system detects threshold sensitivity by analyzing the observed eye gaze data. The area under curve (AUC) of the log CSF and best-corrected distance Snellen visual acuity (BCVA) were tested monocularly in each eye. AMD type was assessed using Spectralis OCT B-scans and clinical records. Descriptive statistics comparing AUC by AMD groups were reported. Linear regression analyses were used to evaluate the association between AUC and BCVA.
Results :
A total of 66 eyes of 33 subjects (mean age 78.9 ± 8.1 years; 21 females) with AMD completed monocular CSF testing. AUC of log CSF (mean ± SD) were worst in eyes with GA (19.9 ± 12.7, N=9) followed by neovascular AMD (32.5 ± 14.0, N=25) and early/ intermediate AMD (44.0 ± 12.4, N=32). Worse BCVA was moderately correlated with poor AUC (Pearson r = 0.42, p<0.001). In 25 eyes with BCVA of 20/20 (38% of eyes in the cohort), AUC values ranged from 5 to 58 (42.6 ± 14.1) suggesting a range of variability of poor CSF even in eyes with normal central visual acuity. AUC of log CSF did not differ between phakic and pseudophakic eyes (39.3 ± 14.5, N=26 vs 34.4 ± 15.8, N=40).
Conclusions :
In this pilot study, CSF objectively measured with the novel gaze tracking-based VR headset showed a trend to differentiate among AMD groups. The test was objective, quickly administered, and broadly acceptable across a large age range and lens status tested in this study. Ongoing normative and AMD studies may help support its use as a functional outcome for clinical trials aimed at treating AMD.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.