Macular Pigment and Retinal Thickness in the Second Carotenoids in Age-Related Eye Disease Study (CAREDS2), an ancillary study of the Women’s Health Initiative

Abstract

Purpose : Macular pigment (MP), comprised of lutein and zeaxanthins, may protect the retina against age-related changes and pathology by reducing light damage, and protecting against oxidative stress. Retinal thickness has been observed to decrease with age, as a result of apoptosis of photoreceptors and other neural cells. Previously reported relationships between macular pigment optical density (MPOD) and central retinal thickness are inconsistent and limited to cross-sectional studies. We describe relationships of MPOD to thickness of the central subfield (CST) an average of 15 years later.

Methods : This analysis includes 861 eyes of 440 women, aged 53-86 years, with MPOD measured at CAREDS baseline (2001-2004) and CAREDS2 follow-up (2016-2018). Spectral domain optical coherence tomography images were obtained at CAREDS2, and segmented using automated software with manual correction (Heidelberg Spectralis, Heidelberg, Germany). MPOD measures at baseline and follow-up were obtained using customized heterochromatic flicker photometry; measures at 0.5^o degrees from the foveal center (reference: 7^o) are used in the analyses. Relationships of MPOD to the thickness of the neural retina in the central 1 mm subfield were analyzed using Generalized Estimating Equations (GEE).

Results : Mean CST in the CAREDS2 cohort was unrelated to age, but was 5.1% greater (mean±SD: 266+2 vs. 253+30 um; P_trend <0.0001) in women in the highest compared to the lowest MPOD quartiles at baseline (range: 0.5 to 1.0 vs. 0 to 0.2 optical density units). Associations were attenuated in women with intermediate or worse age-related macular degeneration. Mean CST was also greater in women who increased MPOD between baseline and follow-up (mean±SD CST among women in lowest vs highest quintiles for MPOD change: 273±3 vs 280±3; P_trend 0.009.) Eyes with yellow-tinted intra-ocular lenses (IOLs) placed since baseline had slightly higher CST than those with clear IOLs (mean±SD: 255±3 vs 262±2 µm; P_trend = 0.04).

Conclusions : Greater mean retinal thickness in CAREDS2 participants, after 15 years of follow-up, was associated with higher MPOD, greater increases in MPOD, and the insertion of yellow-tinted IOLs. These results are consistent with previous evidence suggesting that protection against visible light damage may preserve retinal integrity.

This is a 2020 ARVO Annual Meeting abstract.