THE LINK BETWEEN CHOLESTEROL AND EYE HEALTH

Cholesterol, particularly high-density lipoprotein cholesterol (HDL-C), has long been recognized for its role in heart health. However, emerging evidence is now shedding light on the important role it plays in age-related eye diseases. As we age, conditions such as age-related macular degeneration (AMD), cataracts, glaucoma, and diabetic retinopathy (DR) become increasingly prevalent. Research suggests that cholesterol levels may influence the pathogenesis and progression of these conditions, highlighting the need for better understanding and management of cholesterol for preserving eye health.

Cholesterol and Age-Related Macular Degeneration (AMD)

Age-related macular degeneration (AMD) is one of the leading causes of vision loss in older adults. Recent genetic studies have identified a surprising connection between HDL-C and AMD. A large-scale study using Mendelian randomization across European and Asian populations found that higher HDL-C levels were associated with an increased risk of advanced AMD. Specifically, a 1 standard deviation increase in HDL-C levels resulted in a 17% increased risk for Europeans and a 58% increased risk for Asians (Fan et al., 2017).

This finding challenges the traditional belief that higher HDL-C levels are protective. Instead, it suggests that elevated HDL-C may contribute to AMD pathogenesis, making it a potential target for future therapeutic strategies aimed at preventing or treating the disease.

Cholesterol, Cataracts, and Oxidative Stress

Cataracts, which cause the clouding of the eye’s lens, are another age-related condition linked to cholesterol. Research has shown that high cholesterol, particularly HDL-C, may contribute to cataract formation through oxidative stress pathways. Oxidative stress damages the proteins in the lens, leading to cloudiness and impaired vision. Studies have suggested that HDL-C’s antioxidant properties might not be sufficient to counteract the oxidative damage in the lens, particularly when HDL levels are elevated (Betzler et al., 2020).

The relationship between cholesterol and cataracts requires further investigation, but current evidence suggests that managing cholesterol levels could be crucial for preventing cataract formation as part of an overall strategy for maintaining eye health.

HDL-C and Glaucoma

Glaucoma, a condition characterized by optic nerve damage and often elevated intraocular pressure, has also been studied in relation to cholesterol levels. Some studies have explored the antioxidative effects of HDL-C in glaucoma, given its potential to protect against oxidative stress, a known contributor to glaucoma’s progression. However, the current literature is inconclusive, with some studies finding no significant link between cholesterol levels and glaucoma risk (Betzler et al., 2020).

While the potential role of HDL-C in glaucoma remains unclear, continued research is necessary to better understand how cholesterol might influence the development and progression of this vision-threatening condition.

Cholesterol and Diabetic Retinopathy (DR)

Diabetic retinopathy (DR) is another age-related eye disease that has been linked to lipid metabolism. Research has shown that patients with diabetes who have elevated cholesterol levels, particularly high HDL-C, are at an increased risk for DR. This condition results from damage to the blood vessels in the retina, and cholesterol may exacerbate this process through inflammation and oxidative damage. The relationship between HDL-C and DR suggests that managing lipid profiles could help prevent or slow the progression of retinopathy in diabetic patients (Betzler et al., 2020).

Cholesterol and Cognitive Decline

In addition to its role in eye health, cholesterol has been implicated in cognitive decline. High cholesterol, particularly LDL-C, is a well-known risk factor for cardiovascular disease, but recent studies suggest that it may also contribute to the development of dementia. A major review study indicated that untreated vision loss, particularly due to cataracts or diabetic retinopathy, increases the risk of cognitive decline by up to 47% (Livingston et al., 2024). This suggests that maintaining eye health through cholesterol management may also have implications for cognitive function, especially in aging populations.

The Need for Balanced Cholesterol Management

The growing body of research underscores the need for a balanced approach to cholesterol management, not only for cardiovascular health but also for preserving eye health. High levels of HDL-C, once thought to be protective, may increase the risk of age-related ocular diseases like AMD, cataracts, and diabetic retinopathy. Managing cholesterol levels through diet, lifestyle changes, and medical intervention is crucial to prevent these conditions and preserve vision as we age.

Vision Care encourages everyone to monitor their cholesterol levels and schedule regular eye check-ups, particularly if they are at higher risk for age-related eye diseases. By understanding the links between cholesterol and eye health, we can take proactive steps to reduce the risk of vision loss in the future.

References

Betzler, B.K., et al., 2020. High-density lipoprotein cholesterol in age-related ocular diseases. Biomolecules, 10(4), p.645. https://doi.org/10.3390/biom10040645

Fan, Q., et al., 2017. HDL-cholesterol levels and risk of age-related macular degeneration: A multiethnic genetic study using Mendelian randomization. International Journal of Epidemiology, 46(6), pp.1891-1902. https://doi.org/10.1093/ije/dyx189

Livingston, G., et al., 2024. Vision loss and high cholesterol recognised as dementia risk factors. The Lancet, 31 July 2024. https://doi.org/10.1016/S0140-6736(24)01296-0

Runz, H., et al., 2021. HDL-C and its influence on oxidative stress in glaucoma. Vision Research, https://doi.org/10.1016/j.visres.2020.11.001

Gorski, M., et al., 2023. Cholesterol and its impact on diabetic retinopathy progression. Diabetic Retinopathy Journal, https://doi.org/10.1016/j.diare.2023.03.001