Macular pigment and functional vision in older patients

Introduction

Falls in older adults are commonly attributed to aging, reduced mobility, or outdated spectacle prescriptions. While these factors are relevant, such explanations often overlook a critical contributor: the quality of visual function.

In clinical practice, vision assessment remains heavily centered on visual acuity. However, many older patients with acceptable acuity continue to report difficulty navigating steps, walking in dim lighting, or adapting to glare. This discrepancy suggests that visual acuity alone does not adequately reflect real-world visual performance.

Emerging evidence supports a broader understanding of vision—one that includes functional components such as contrast sensitivity, depth perception, and visual processing. Within this framework, macular pigment optical density (MPOD) has gained attention as a potential link between nutrition, visual quality, and functional performance in aging.

Vision and falls: The role of functional visual parameters

Vision plays a central role in maintaining balance by providing continuous spatial information about the environment. When visual input is degraded, postural stability is compromised, increasing fall risk.

Importantly, studies have shown that contrast sensitivity and depth perception are more strongly associated with falls than visual acuity alone.¹ These functions are critical for detecting edges, steps, and subtle environmental hazards, particularly under low contrast or suboptimal lighting conditions.

At the same time, aging is associated with a natural decline in contrast sensitivity, especially under glare and mesopic conditions.² Depth perception may also deteriorate due to changes in binocular vision and neural processing. These deficits can occur even in patients with relatively preserved visual acuity.

This highlights a key clinical insight: Fall risk is closely linked to functional vision, not just refractive clarity.

MPOD as a determinant of visual quality

Macular pigment, composed of lutein, zeaxanthin, and meso-zeaxanthin, is uniquely positioned to influence visual quality. By selectively absorbing short-wavelength light and reducing intraocular scatter, macular pigment enhances the quality of the retinal image.

Higher MPOD has been associated with improved visual performance, including better visual acuity and enhanced performance under glare conditions.³ Importantly, MPOD also contributes to improved contrast perception by increasing the signal-to-noise ratio within the visual system.

In this context, MPOD can be viewed as a biological modulator of functional vision—one that directly influences the very parameters (contrast sensitivity and visual clarity under challenging conditions) known to be associated with fall risk.

Conversely, reduced MPOD may contribute to poorer visual quality, exacerbate functional deficits in aging, and be associated with age-related macular degeneration. In contrast, lower MPOD is often observed in affected individuals.³

From visual quality to functional performance

The significance of MPOD extends beyond optical effects. Lutein and zeaxanthin are also present in the brain, where they are believed to support neural processing and cognitive function.

Lower MPOD has been associated with reduced cognitive performance, including slower processing speed and diminished executive function.^4,5 These cognitive domains are essential for interpreting visual information and coordinating movement.

Furthermore, supplementation with macular carotenoids has been shown to improve eye–hand coordination and visuomotor performance.⁶These findings are particularly relevant to fall risk, as safe mobility depends on the integration of visual input with motor responses.

Thus, MPOD represents more than a retinal parameter: It reflects a functional axis linking vision, brain, and movement.

Nutritional considerations in older adults

Despite living in developed, food-rich environments, many older adults experience suboptimal nutrition. Based on Singapore research, approximately 22% of older individuals are at a moderate-to-high risk of malnutrition even with a readily accessible food source.⁷

Lower nutrition may be due to age-related physiological changes, including reduced appetite, altered taste, and impaired chewing or digestion, leading to limited nutrient intake. Social and economic factors further influence dietary patterns, often leading to reduced consumption of nutrient-dense foods.⁸

Therefore, it is vital to review the nutritional intake of older adults. As lutein and zeaxanthin are entirely diet-derived, inadequate intake may lead to reduced MPOD levels. This creates a direct pathway through which nutrition can influence visual quality and, potentially, functional performance.

Reframing lutein: Beyond retinal disease

Generally, lutein and zeaxanthin are traditionally associated with age-related macular degeneration. However, their role extends beyond disease prevention and into broader aspects of functional performance in daily life.

Within the visual system, these carotenoids enhance MPOD and improve visual quality, particularly under glare and reduced contrast conditions.³ Beyond the eye, lutein has been associated with improved brain function, including enhanced neural efficiency and cognitive performance in older adults.⁹

Importantly, emerging evidence suggests that macular carotenoids also influence visuomotor function. Supplementation with lutein, zeaxanthin, and related carotenoids has been shown to improve eye–hand coordination and visual processing efficiency.⁶ These functions are critical for everyday activities such as reaching, stepping, and navigating the environment—tasks that are directly relevant to mobility and fall risk in older adults.

Additionally, lutein exhibits antioxidant and anti-inflammatory properties that may help mitigate age-related decline.¹⁰

This broader perspective positions lutein not only as a retinal protective agent but also as a functional nutrient supporting visual performance, neurological processing, and coordinated movement in aging individuals.

Clinical implications: Why MPOD matters in practice

The established relationship between functional vision and fall risk highlights the need for a more comprehensive approach to visual assessment in older adults.

While contrast sensitivity and depth perception remain important clinical measures, they represent downstream functional outcomes. MPOD offers an upstream perspective by reflecting the underlying biological and nutritional factors that influence visual quality.

Despite its clinical relevance, MPOD assessment remains underutilized in routine optometric practice. This is notable given that it is a noninvasive, relatively quick, and patient-friendly technique that can be easily incorporated into clinical workflows. Unlike traditional measures that focus primarily on refractive status, MPOD provides simultaneous insight into retinal health, visual quality, and nutritional status.

Integrating MPOD evaluation into practice allows optometrists to move beyond a purely refractive model of care. It enables the identification of patients who may benefit from nutritional intervention, particularly in populations at risk of suboptimal dietary intake, such as older adults. When combined with functional vision assessment and targeted dietary or supplementation advice, MPOD becomes a valuable tool in supporting a more holistic approach to patient care.

In an aging society, such an approach is increasingly relevant. By incorporating MPOD into routine assessment, optometrists can contribute not only to improved visual performance but also to broader functional outcomes and overall quality of life in older adults.

Conclusion

Falls in older adults are multifactorial, with vision playing a central and modifiable role. While contrast sensitivity and depth perception are key contributors, they reflect broader underlying changes in visual function (Figure).

Expanding optometric care to include functional vision assessment and nutritional strategies—particularly the role of macular carotenoids such as lutein and zeaxanthin—offers a practical pathway to support healthy aging. In doing so, optometrists can move beyond refractive correction and play a more active role in enhancing the quality of life and maintaining functional independence in older adults.

References

1. Lord SR. Visual risk factors for falls in older people. Age Ageing. 2006;35(suppl 2):ii42-ii45. doi:10.1093/ageing/afl085

2. Herrero-Gracia A, Hernández-Andrés R, Luque MJ, Díez-Ajenjo MA. Age-related changes in contrast sensitivity function under different illumination conditions. Clin Exp Optom. 2025;108(7):880-885. doi:10.1080/08164622.2025.2483265

3. Puell MC, Palomo-Alvarez C, Barrio AR, Gómez-Sanz FJ, Pérez-Carrasco MJ. Relationship between macular pigment and visual acuity in eyes with early age-related macular degeneration. Acta Ophthalmol. 2013;91(4):e298-e303. doi:10.1111/aos.12067

4. Feeney J, Finucane C, Savva GM, et al. Low macular pigment optical density is associated with lower cognitive performance in a large, population-based sample of older adults. Neurobiol Aging. 2013;34(11):2449-2456. doi:10.1016/j.neurobiolaging.2013.05.007

5. Vishwanathan R, Iannaccone A, Scott TM, et al. Macular pigment optical density is related to cognitive function in older people. Age Ageing. 2014;43(2):271-275. doi:10.1093/ageing/aft210

6. Yoshida K, Sakai O, Honda T, et al. Effects of astaxanthin, lutein, and zeaxanthin on eye-hand coordination and smooth-pursuit eye movement after visual display terminal operation in healthy subjects: a randomized, double-blind, placebo-controlled intergroup trial. Nutrients. 2023;15(6):1459. doi:10.3390/nu15061459

7. Ye KX, Sun L, Lim SL, et al. Adequacy of nutrient intake and malnutrition risk in older adults: findings from the Diet and Healthy Aging Cohort Study. Nutrients. 2023;15(15):3446. doi:10.3390/nu15153446

8. Govindaraju T, Owen AJ, McCaffrey TA. Past, present and future influences of diet among older adults: a scoping review. Ageing Res Rev. 2022;77:101600. doi:10.1016/j.arr.2022.101600

9. Yagi A, Nouchi R, Butler L, Kawashima R. Lutein has a positive impact on brain health in healthy older adults: a systematic review of randomized controlled trials and cohort studies. Nutrients. 2021;13(6):1746. doi:10.3390/nu13061746

10. Ye J, Cheng J, Xiong R, et al. Effects and mechanisms of lutein on aging and age-related diseases. Antioxidants (Basel). 2024;13(9):1114. doi:10.3390/antiox13091114