Abstract
Accurate clinical assessment of Macular Pigment Optical Density (MPOD) using Heterochromatic Flicker Photometry (HFP) requires the HFP stimulus be presented at or near a specific “ideal” frequency. If the frequency is too low, fusion never occurs and the task is difficult for naive patients. If the frequency is too high, fusion occurs in a wide range of values, and measurement error is high. Determining this frequency is time consuming and difficult to determine in a clinical setting. Critical Flicker Fusion (CFF) frequency is easy to assess using standard densitometry equipment in naive patients. By correlating CFF and the “ideal” frequency for HFP densitometry for a given densitometer, HFP frequency selection can be made quickly and accurately from the comparatively easier CFF assessment. A methodology for determining “ideal” HFP frequency was developed using a Macular Metrics II (tm) Macular Pigment Optical Densitometer. “Ideal” HFP frequencies show positive correlation to CFF frequency allowing a straightforward algorithm to be derived.