Macular pigment measurement by heterochromatic flicker photometry in older subjects: the carotenoids and age-related eye disease study.

Julie Mares // Publications // Feb 01 2004

PubMed ID: 14744895

Author(s): Snodderly DM, Mares JA, Wooten BR, Oxton L, Gruber M, Ficek T; CAREDS Macular Pigment Study Group. Macular pigment measurement by heterochromatic flicker photometry in older subjects: the carotenoids and Age-Related Eye Disease Study. Invest Ophthalmol Vis Sci. 2004 Feb;45(2):531-8. PMID 14744895

Journal: Investigative Ophthalmology & Visual Science, Volume 45, Issue 2, Feb 2004

PURPOSE To develop a standardized protocol for measuring macular pigment optical density (MPOD) of experimentally naïve subjects by heterochromatic flicker photometry (HFP).

METHODS MPOD in eyes of 54 women, age 50 and 79 years (mean, 66), was studied. The spatial profile of MPOD was measured in the right eye, and two spatial points were also measured in the left eye. Forty-eight of these inexperienced subjects completed the protocol on two separate visits. For a subset of the group, the MPOD at two different wavelengths was measured.

RESULTS The test-retest correlation at 0.5 degrees eccentricity in the right eye was 0.9. On the second visit, more than 90% of the subjects were able to perform the HFP test with results that were consistent with the absorption spectrum of macular pigment. On the first visit, data from the inexperienced subjects deviated more from the expected relationships between the two wavelengths, presumably because they had less skill in performing the task. However, subjects with high or low macular pigment density were distinguished clearly.

CONCLUSIONS Reliable and meaningful measurements of macular pigment density in older subjects can be made using HFP, with a standardized protocol in the limited time available in large epidemiologic studies. This protocol will be made freely available to other researchers on request.