An evaluation of two candidate functional biomarkers for AMD

Area of Science:

• Ophthalmology
• Visual Science
• Biomarker Research

Background:

• Age-related macular degeneration (AMD) is a leading cause of vision loss.
• Early detection and monitoring of AMD are crucial for effective management.
• Functional biomarkers are needed to assess visual function changes in AMD.

Purpose of the Study:

• To assess the intersession repeatability of the Colour Assessment and Diagnosis (CAD) test and a 14-Hz flicker test.
• To establish benchmark data for these tests in healthy individuals.
• To evaluate their potential as functional biomarkers for AMD.

Main Methods:

• 30 healthy adults underwent visual function testing using CAD and 14-Hz flicker tests on two separate days.
• Intersession repeatability was determined by calculating the coefficient of repeatability (CoR).
• RG and YB CAD thresholds and 14-Hz flicker contrast thresholds were measured.

Main Results:

• Coefficients of repeatability (CoR) were calculated: 0.39 CAD units for RG, 0.43 CAD units for YB, and 0.015 for 14-Hz flicker.
• Small but consistent learning effects were observed between visits (4.72% RG, 6.33% YB, 13.3% 14-Hz flicker).
• The CoR values were relatively small compared to the mean thresholds, indicating good repeatability.

Conclusions:

• The CAD and 14-Hz flicker tests demonstrate acceptable repeatability in healthy adults.
• These tests provide valuable data for assessing clinical significance in repeated measures.
• Sufficient training is recommended in clinical trials to mitigate learning effects.