Biomarkers - Retinal Function
Retinal Function
This section documents carotenoid biomarkers relevant to retinal and macular health.
Retinal Function Biomarkers
Click each heading to expand details of this biomarker.
Overview
What is it? Lutein is a dietary xanthophyll carotenoid found particularly in green leafy vegetables and other foods. It accumulates in tissues including the retina, where together with zeaxanthin it forms macular pigment, and has antioxidant properties.
Research relevance: Can be used to investigate carotenoid and nutritional status and their associations with visual and macular health. In ageing research, circulating lutein can also be examined in relation to cognitive function and other age-related health outcomes.
Sample type: Frozen, photo-protected K2EDTA blood plasma
Sample Collection / Handling
Plasma isolated from 10 mL of fresh whole blood, maintained at 2–4°C for 24–48 hours after blood collection and subsequently frozen at −80°C. A 1 mL plasma aliquot was protected from light by wrapping in tinfoil and stored at −80°C.
Assay / Measurement
Method: Reversed-phase high-performance liquid chromatography (HPLC). Method validation used NIST 986e Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum Reference Standard, with quality checks performed using control plasma samples.
Equipment / analyser: HPLC system
Laboratory: Macular Pigment Research Group, Vision Research Centre, Waterford, Ireland
Measurement Characteristics
| Characteristic | Value |
|---|---|
| Units | umol/L |
| Measurement range | 0.0021- 3.0000 mmol/L |
| Lower detection limit | 0.0021mmol/L |
| Assay CoV | 0.04 |
Collection Waves
| Biomarker | Wave 1 | Wave 2 | Wave 3 | Wave 4 | Wave 5 | Wave 6 |
|---|---|---|---|---|---|---|
| Lutein (Macular Carotenoid) | X |
Reference
- Buscemi, S., Corleo, D., Di Pace, F., Petroni, M.L., Satriano, A. and Marchesini, G. (2018) ‘The effect of lutein on eye and extra-eye health’, Nutrients, 10(9), p. 1321. doi:10.3390/nu10091321.
Example TILDA Papers
- Feeney J, O’Leary N, Moran R, O’Halloran AM, Nolan JM, Beatty S, Young IS, Kenny RA. Plasma Lutein and Zeaxanthin Are Associated With Better Cognitive Function Across Multiple Domains in a Large Population-Based Sample of Older Adults: Findings from The Irish Longitudinal Study on Aging. J Gerontol A Biol Sci Med Sci. 2017 Oct 1;72(10):1431-1436. https://doi.org/10.1093/gerona/glw330
- O’Halloran AM, Laird EJ, Feeney J, Healy M, Moran R, Beatty S, Nolan JM, Molloy AM, Kenny RA. Circulating Micronutrient Biomarkers Are Associated With 3 Measures of Frailty: Evidence From the Irish Longitudinal Study on Ageing. J Am Med Dir Assoc. 2020 Feb;21(2):240-247.e5. https://doi.org/10.1016/j.jamda.2019.06.011
- Moran R, Nolan JM, Stack J, O’Halloran AM, Feeney J, Akuffo KO, Kenny RA, Beatty S. Non-Dietary Correlates and Determinants of Plasma Lutein and Zeaxanthin Concentrations in the Irish Population. J Nutr Health Aging. 2017;21(3):254-261. https://doi.org/10.1007/s12603-016-0729-7
Other References
- Nolan JM, Loskutova E, Howard AN, Moran R, Mulcahy R, Stack J, Bolger M, Dennison J, Akuffo KO, et al. Macular pigment, visual function, and macular disease among subjects with Alzheimer’s disease: an exploratory study. J Alzheimers Dis. 2014;42:1191-202. https://doi.org/10.3233/jad-140507
Overview
What is it? Zeaxanthin is a dietary xanthophyll carotenoid found in foods including leafy green vegetables, yellow and orange fruits and vegetables, and egg yolk. Together with lutein, zeaxanthin accumulates in the retina where it forms part of the macular pigment and has antioxidant properties.
Research relevance: Can be used to investigate carotenoid and nutritional status and their associations with visual and macular health. In ageing research, circulating zeaxanthin can also be examined in relation to cognitive function and other age-related health outcomes.
Sample type: Frozen, photo-protected K2EDTA blood plasma
Sample Collection / Handling
Plasma isolated from 10 mL of fresh whole blood, maintained at 2–4°C for 24–48 hours after blood collection and subsequently frozen at −80°C. A 1 mL plasma aliquot was protected from light by wrapping in tinfoil and stored at −80°C.
Assay / Measurement
Method: Reversed-phase high-performance liquid chromatography (HPLC). Method validation used NIST 986e Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum Reference Standard, with quality checks performed using control plasma samples.
Equipment / analyser: HPLC system; specific equipment not provided
Laboratory: Macular Pigment Research Group, Vision Research Centre, Waterford, Ireland
Measurement Characteristics
| Characteristic | Value |
|---|---|
| Units | umol/L |
| Measurement range | 0.0027- 5.0000 mmol/L |
| Lower detection limit | 0.0027mmol/L |
| Assay CoV | 0.068 |
Collection Waves
| Biomarker | Wave 1 | Wave 2 | Wave 3 | Wave 4 | Wave 5 | Wave 6 |
|---|---|---|---|---|---|---|
| Zeaxanthin (Macular Carotenoid) | X |
Reference
- Buscemi, S., Corleo, D., Di Pace, F., Petroni, M.L., Satriano, A. and Marchesini, G. (2018) ‘The effect of lutein on eye and extra-eye health’, Nutrients, 10(9), p. 1321. doi:10.3390/nu10091321.
Example TILDA Papers
- Feeney J, O’Leary N, Moran R, O’Halloran AM, Nolan JM, Beatty S, Young IS, Kenny RA. Plasma Lutein and Zeaxanthin Are Associated With Better Cognitive Function Across Multiple Domains in a Large Population-Based Sample of Older Adults: Findings from The Irish Longitudinal Study on Aging. J Gerontol A Biol Sci Med Sci. 2017 Oct 1;72(10):1431-1436. https://doi.org/10.1093/gerona/glw330
- O’Halloran AM, Laird EJ, Feeney J, Healy M, Moran R, Beatty S, Nolan JM, Molloy AM, Kenny RA. Circulating Micronutrient Biomarkers Are Associated With 3 Measures of Frailty: Evidence From the Irish Longitudinal Study on Ageing. J Am Med Dir Assoc. 2020 Feb;21(2):240-247.e5. https://doi.org/10.1016/j.jamda.2019.06.011
- Moran R, Nolan JM, Stack J, O’Halloran AM, Feeney J, Akuffo KO, Kenny RA, Beatty S. Non-Dietary Correlates and Determinants of Plasma Lutein and Zeaxanthin Concentrations in the Irish Population. J Nutr Health Aging. 2017;21(3):254-261. https://doi.org/10.1007/s12603-016-0729-7
Other References
- Nolan JM, Loskutova E, Howard AN, Moran R, Mulcahy R, Stack J, Bolger M, Dennison J, Akuffo KO, et al. Macular pigment, visual function, and macular disease among subjects with Alzheimer’s disease: an exploratory study. J Alzheimers Dis. 2014;42:1191-202. https://doi.org/10.3233/jad-140507