Background/aims Macular pigment is thought to protect the macula against exposure to light and oxidative stress, both of which may play a role in the development of age-related macular degeneration. The aim was to clinically evaluate a novel cathode-ray-tube-based method for measurement of macular pigment optical density (MPOD) known as apparent motion photometry (AMP).
Methods The authors took repeat readings of MPOD centrally (0°) and at 3° eccentricity for 76 healthy subjects (mean (±SD) 26.5±13.2 years, range 18–74 years).
Results The overall mean MPOD for the cohort was 0.50±0.24 at 0°, and 0.28±0.20 at 3° eccentricity; these values were significantly different (t=−8.905, p<0.001). The coefficients of repeatability were 0.60 and 0.48 for the 0 and 3° measurements respectively.
Conclusions The data suggest that when the same operator is taking repeated 0° AMP MPOD readings over time, only changes of more than 0.60 units can be classed as clinically significant. In other words, AMP is not suitable for monitoring changes in MPOD over time, as increases of this magnitude would not be expected, even in response to dietary modification or nutritional supplementation.
- Age-related macular degeneration
- apparent motion photometry
- macular pigment
- macular pigment optical density
- Accepted 18 July 2010
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Funding HB was funded by a grant from the Macular Disease Society.
Competing interests None.
Patient consent Obtained.
Ethics approval Ethics approval was provided by the Aston University Human Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.