Older adults commonly experience a gradual loss of visual sharpness and depth perception with age, and the incidence of some eye health issues also increases. The health of the eyes may be as a direct result of problems of the eye itself, or elsewhere in the body.

What are cataracts?

Cataracts cloudy areas of the lens inside the eye, which are seen from the outside as whiteness inside the pupil, which is usually black. They are more common in elderly adults, with rates increasing 3% in middle-age to 40% at >75 years [1]. They form in one or both eyes, but don’t spread between eyes.

The function of the lens, like in a camera, is to focus images onto the light sensitive retina at the back of the eye. The lens is naturally flexible and muscles within the eye squash or stretch it automatically to help us focus. With cataracts, the density and hardness of the soft tissue inside lens increase. So the person with the cataract perceives what they see as blurry, hazy or less colorful, and with lower distance vision.

Cataracts are common in countries where there is a higher level of malnutrition than developed countries. Deficiencies in specific micronutrients such as carotenoids (e.g. beta-carotene, lutein, zeaxanthin, vitamin A, C, D, E and K [2-4], have been linked to cataract formation. Lifestyle factors such as smoking, or overexposure to UV light, cause cellular damage may also accelerate the natural aging process within the lens and exacerbate the problem.

What is glaucoma?

Glaucoma is the leading cause of reversible vision loss worldwide [5] and affects around 2.2% of the global population, but the risk increases over 60 years of age. It results from an increasing fluid pressure within the eye, which presses on the retina and optic nerve at the back of the eye, causing progressive vision loss.

The pressure increases because of accumulation of eye fluid in front of the lens (open angle glaucoma) or behind the lens (closed angle glaucoma), due to a problem with fluid drainage. This causes what is described as “tunnel vision” – where peripheral vision is darker or blurrier.

Lack of vitamin D in the diet has been associated with an increase in glaucoma risk [6, 7] and may be involved in the inflammatory processes that are increased with glaucoma, as well as diabetes and blood vessel problems. Excessive alcohol consumption has also been implicated in the elevation of intra-ocular pressures [7].

What is age-related macular degeneration (AMD)?

AMD, as the name suggests, is a breakdown of the macula, the middle part of the light sensitive retina at the back of the eye. The macula is responsible for detailed, close-up vision, and has a higher concentration of cone cells (cells that see under bright light conditions) and carotenoids such as lutein.

The degeneration occurs because of a thinning of the macula, build up of deposits, or pressure from small blood vessels behind the eye. These cause damage spots that result in blurriness of the middle of the visual field and difficulty in activities like reading and writing

Many studies have shown that improvements in the intake of carotenoids (lutein, zeaxanthin, beta carotene), omega-3’s and zinc reduced the likelihood of developing AMD [8]. While lifestyle factors such as smoking, UV and blue light over-exposure, obesity, high cholesterol and blood vessel health problems may play a negative role [9].

How do lifestyle factors affect ocular health?

The eye is a delicate part of the body and although there are naturally occurring change to eye function and vision, some lifestyle factors may push the envelope further. The eye might seem like it doesn’t do much, but in fact the retina has one of the most energy demanding roles in the body and is sensitive to processes such as photo-oxidation.

Older adults not only stay awake longer but may spend more time exposing their eyes to flat screen devices than similar age groups in previous decades. Some simple advice that may help would be to rest the eyes periodically and maintain a healthy diet and lifestyle approach.

References

1. Klein, B.E., R. Klein, and K.E. Lee, Incidence of age-related cataract: the Beaver Dam Eye Study. Arch Ophthalmol., 1998. 116(2): p. 219-25. doi: 10.1001/archopht.116.2.219.
2. Ravindran, R.D., et al., Inverse association of vitamin C with cataract in older people in India. Ophthalmology., 2011. 118(10): p. 1958-1965.e2. doi: 10.1016/j.ophtha.2011.03.016. Epub 2011 Jun 25.
3. Jiang, H., et al., Dietary vitamin and carotenoid intake and risk of age-related cataract. Am J Clin Nutr., 2019. 109(1): p. 43-54. doi: 10.1093/ajcn/nqy270.
4. Sella, R. and N.A. Afshari, Nutritional effect on age-related cataract formation and progression. Curr Opin Ophthalmol., 2019. 30(1): p. 63-69. doi: 10.1097/ICU.0000000000000537.
5. https://www.hopkinsmedicine.org/health/conditions-and-diseases/glaucoma.
6. Huynh, B., et al., Low systemic vitamin D as a potential risk factor in primary open-angle glaucoma: a review of current evidence. Br J Ophthalmol., 2021. 105(5): p. 595-601. doi: 10.1136/bjophthalmol-2020-316331. Epub 2020 Jun 30.
7. Goncalves, A., et al., Serum vitamin D status is associated with the presence but not the severity of primary open angle glaucoma. Maturitas., 2015. 81(4): p. 470-4. doi: 10.1016/j.maturitas.2015.05.008. Epub 2015 May 30.
8. Di Carlo, E. and A.J. Augustin, Prevention of the Onset of Age-Related Macular Degeneration. J Clin Med., 2021. 10(15): p. 3297. doi: 10.3390/jcm10153297.
9. Chakravarthy, U., et al., Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis. BMC Ophthalmol., 2010. 10:31.(doi): p. 10.1186/1471-2415-10-31.

from an Expert Author

George Thouas

BSc, MRepSc, PhD – Biomedical Scientist

George has worked as a medical researcher for 17 years in the university sector, at both Monash University health institutes, and The University of Melbourne. He spent 12 of those years in reproductive health and fertility research, in roles such as Clinical Research Associate, Clinical Embryologist, Post-graduate Demonstrator, Lecturer, and later as a Senior Research Fellow and Lab Manager. His doctoral thesis investigated the effects of mitochondrial damage in the oocyte. He also worked on improving the nutrient and growth requirements for in vitro fertilization and embryo development.

George has authored and coauthored more than 50 publications, including 1 book, 5 book chapters, 30 peer-reviewed journal reports and reviews, 6 patents, international scientific conference proceedings and health practitioner journal articles.

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