Clinical evaluation of the MacuScope macular pigment densitometer
- Correspondence to Dr Hannah Bartlett, Ophthalmic Research Group, School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK; H.E.Bartlett{at}aston.ac.uk
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Contributors All named authors were involved in the conception and design of the study, analysis and interpretation of data, drafting the article and revising it critically for important intellectual content. All named authors gave final approval of the version published. HB and JA collected the data. FE provided training on data collection methods.
- Accepted 5 October 2009
- Published Online First 22 October 2009
Abstract
Background/aims The MacuScope uses a psychophysical technique called heterochromic flicker photometry to measure macular pigment optical density (MPOD). Our aim was to determine the measurement variability (noise) of the MacuScope.
Methods Thirty-eight normally sighted participants who ranged in age from 19 to 46 years (25.7±7.6 years) were recruited from staff and students of Aston University. Data were collected by two operators, HB and JA, in two sessions separated by 1 week in order to assess test repeatability and reproducibility.
Results The overall mean MPOD for the cohort was 0.47±0.14. There was a significant negative correlation between MacuScope MPOD readings and age (r=−0.368, p=0.023). Coefficients were 0.45 and 0.58 for repeatability, and 0.49 and 0.36 for reproducibility. For each pair of results, there was a significant positive correlation between mean and difference MPOD values.
Conclusions If MPOD is being monitored over time then any change less than 0.58 units should not be considered clinically significant as it is very likely to be due to instrument noise. The size of the coefficient appears to be positively correlated with MPOD.
Footnotes
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Competing interests None.
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Ethics approval This study was conducted with the approval of the Aston University Human Ethics Committee.
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Patient consent Obtained.
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Provenance and peer review Not commissioned; externally peer reviewed.
