Mobile app Aston contrast sensitivity test

Abstract

Background

Contrast detection is an important aspect of the assessment of visual function; however, clinical tests evaluate limited spatial frequencies and contrasts. This study validates the accuracy and inter‐test repeatability of a swept‐frequency near and distance mobile app Aston contrast sensitivity test, which overcomes this limitation compared to traditional charts.

Method

Twenty subjects wearing their full refractive correction underwent contrast sensitivity testing on the new near application (near app), distance app, CSV‐1000 and Pelli–Robson charts with full correction and with vision degraded by 0.8 and 0.2 Bangerter degradation foils. In addition repeated measures using the 0.8 occluding foil were taken.

Results

The mobile apps (near more than distance, p = 0.005) recorded a higher contrast sensitivity than printed tests (p < 0.001); however, all charts showed a reduction in measured contrast sensitivity with degradation (p < 0.001) and a similar decrease with increasing spatial frequency (interaction > 0.05). Although the coefficient of repeatability was lowest for the Pelli–Robson charts (0.14 log units), the mobile app charts measured more spatial frequencies, took less time and were more repeatable (near: 0.26 to 0.37 log units; distance: 0.34 to 0.39 log units) than the CSV‐1000 (0.30 to 0.93 log units). The duration to complete the CSV‐1000 was 124 ± 37-seconds, Pelli–Robson 78 ± 27-seconds, near app 53 ± 15-seconds and distance app 107 ± 36-seconds.

Conclusions

While there were differences between charts in contrast levels measured, the new Aston near and distance apps are valid, repeatable and time‐efficient method of assessing contrast sensitivity at multiple spatial frequencies.

Key words:

• contrast sensitivity
• CSV‐1000
• mobile app
• Pelli–Robson chart
• repeatability
• validity

Acknowledgement

TD and JSW have a financial interest in Aston EyeTech Ltd, which has commercialised the Aston Contrast Sensitivity Apps.