A practical method for measuring macular pigment optical density

PURPOSE. Increasing evidence indicates that the macular pigments (MP) protect the central retina and may retard macular disease. For that reason, a practical method for measuring MP that does not require elaborate optics and can be applied to diverse populations by operators with a modest amount of experience was developed and validated. METHODS. A small tabletop device based on light-emitting diodes (LEDs) as the light source with electronic controls was constructed. Macular pigment a-as measured with the tabletop device with a 1 degrees test stimulus at 460 nm using heterochromatic flicker photometry, and the results were compared with measurements using a traditional three-channel Maxwellian view system with a xenon-are source. RESULTS. Macular pigment density of 30 subjects (age range, 16 - 60 years) was measured with both stimulus systems. Macular pigment measured with the LED tabletop device in free view was highly correlated with MP measured in Maxwellian view (y = -0.03 + 1.06x, r = +0.95). The average absolute difference between the two techniques was 0.04 (SD: 0.03). The new technique was not significantly affected by variations in lens optical density, pupil size, or small head movements. CONCLUSIONS. Pspchophysical measurement of MP provides a unique opportunity to make repeated noninvasive assessment of the concentration of a protective nutrient in the retina. The availability of this new device should make this measurement technology accessible to a wide variety of investigators for application to diverse populations.