HFP reproducibly measures MP spatial profile. Secondary peaks seen in the MP spatial profile cannot be attributed to measurement error and are associated with wider foveas. The slope of an individual's MP spatial profile is related to foveal slope, with a steeper MP distribution associated with a steeper foveal depression.

A central dip in the MP spatial profile, seen in older subjects and in cigarette smokers, may represent an undesirable feature of macular pigmentation. Further research is needed in this area.

The objective of the present study was to investigate whether weight loss is associated with changes in serum concentrations of lutein (L) and zeaxanthin (Z), and/or macular pigment optical density (MPOD). We recruited 104 overweight subjects into this randomised controlled weight loss study. For the intervention group (I group), weight was assessed weekly and body composition, including BMI (kg/m 2 ) and body fat (kg and percentage), was assessed at baseline, 6 and 12 months. Weight loss was encouraged using dietary and exercise programmes. MPOD was measured by heterochromatic flicker photometry and serum concentrations of L and Z by HPLC (at baseline, 1, 3, 6 and 12 months). The control (C) group was assessed at baseline and 12 months. Repeated-measures ANOVA (RMA) demonstrated significant weight loss in the I group over the study period (P¼ 0·000). There was no significant weight change in the C group (P¼0·993). RMA of dietary L and Z, serum L and Z, and MPOD demonstrated no significant time or time £ group interaction effect in any of these parameters (P.0·05 for all), with the exception of a significant decrease in the dietary intake of Z seen in both groups, over the study period (P,0·05). There was a positive and significant relationship between body fat loss (kg) and increase in serum concentrations of L in the I group (r 0·521; P¼ 0·006). Our finding that a reduction in body composition (e.g. fat mass) is related to increases in serum concentrations of L is consistent with the hypothesis that body fat acts as a reservoir for this carotenoid, and that weight loss can positively influence circulating carotenoid levels.

Purpose Studies investigating the relationship between macular pigment optical density (MPOD) and percentage body fat have consistently shown an inverse relationship between these variables. This study was designed to investigate changes in MPOD, and serum concentrations of lutein (L) and zeaxanthin (Z), in response to a weight loss. Methods We plan to recruit 100 subjects into this 12 month, multi‐visit, randomized‐controlled study. Adiposity was assessed by dual energy x‐ray absorbtiometry (DEXA), MPOD was measured using customised heterochromatic flicker photometry (cHFP). Dietary and exercise intervention was provided to subjects enrolled into the intervention group of this study. Inclusion criteria were: age 18‐60 years; body mass index > 28; absence of any ocular pathology; lack of a family history of age‐related maculopathy. Results To date, 93 subjects have been recruited. 22% of existing intervention subjects have lost ≥ 7 kgs in weight. A further 27% have lost up to 3.5 kgs in weight, and are maintaining this trend. Of note, preliminary statistical analysis of 11 subjects based on their 6 month data, indicate a positive, but statistically insignificant, relationship between MPOD and percentage body fat lost. Conclusion Preliminary results indicate a positive relationship between MPOD and weight loss. We await completion of this study and analysis of final results to allow us to comment further on this interesting relationship.