Macular pigment optical density in an ageing Irish population: The Irish longitudinal study on ageing

Purpose: The 3 carotenoids lutein, zeaxanthin, and meso-zeaxanthin, which account for the 'yellow spot' at the macula and which are referred to as macular pigment (MP), are believed to play a role in visual function and protect against age-related macular degeneration (AMD) via their optical and antioxidant properties. This study was undertaken to compare MP optical density (MPOD) in a population aged ≥50 years with MPOD values from a normative database of subjects aged 18-60 years. Methods: Seventy-nine subjects were recruited into this pilot study (The Irish Longitudinal Study on Ageing-TILDA). MPOD was measured using heterochromatic flicker photometry. Retinal fundus photographs, lifestyle data and general health data, were also obtained. Results: The mean ± SD age of the 79 subjects recruited into this study was 65 ± 11 years. There was a moderate, but statistically significant, age-related decline in MPOD at 0.5° in the TILDA data (r = -0.251, p = 0.045), which remained upon merging with a normative database of an additional 462 subjects aged between 18 and 67 years (r = -0.179, p = 0.000). Conclusions: We report an inverse association between MPOD and increasing age. Longitudinal data in a larger cohort of participants are required to satisfactorily investigate the relationship between the optical density of this pigment and age, and with risk for development and/or progression of AMD. This pilot study represents a first step in this endeavour.