gms | German Medical Science

Background: To assess the foveal and total retinal macular pigment (MP) complement in healthy subjects and to monitor the stability of MP spatial distribution profiles for periods of up to two decades.

Methods: Measurements of MP retinal profiles were made by 51 subjects using the psychophysical technique of minimum motion photometry (test 460nm, comparison 580nm). Two foveal fields (0.9º and 2.2º diameter) and 11 annular segments (eccentricities from 0.8º to 7.5º) were used. The total complement within the central 15 degrees was estimated by numerical integration and compared with foveal values. Four subjects with widely different MP profiles underwent annual testing for periods of 21–25 years.

Results: Detailed examinations characterised a wide range of MP distribution profiles using motion photometry. There was a lack of correlation between peak MP optical density at the fovea and assessments of the total complement of MP within the central 15 or 21 degrees. Serial psychophysical assessments over periods of 21–25 years in 4 cases demonstrated a high degree of stability at all macular locations including the fovea; plots of peak MP optical density against time showed slopes ranging from -0.0026 to +0.0029.

Conclusions: The total amount of macular pigment cannot be accurately estimated from foveal values. Widely different MP distribution profiles in healthy subjects demonstrate a high degree of long-term stability in four subjects. This could be pertinent to studies that aim to monitor MP or fundus autofluorescence in disease, or modify MP through dietary supplementation.