Considering cataract surgery and reduction of dementia in Europe

Dementia is a progressive deterioration in cognitive function not related to normal ageing and secondary to different diseases. It results from various diseases and injuries affecting the brain. The most commonly affected areas include memory, visuospatial function, perception, orientation, language, attention and problem solving.

The progression of the manifestations is usually slowly deteriorating, but it changes depending on the different types of dementia. The manifestations include behavioural and psychological symptoms. Behavioural symptoms include agitation, restlessness, inappropriate conduct, sexual disinhibition and aggressiveness. Psychological symptoms include depression, hallucinations and delusions, apathy and anxiety.¹ There is no cure for dementia, even with nonpharmacologic and pharmacologic management. Nonpharmacologic management includes physical activities, social stimulation, intellectual activities, exercise and socialisation. Pharmacologic treatment may offer limited improvement in Alzheimer and Parkinson disease.^1,2,3

The main cause is the increase in the aging population. In Europe, more than one-fifth is older than 65 years, and the life expectancy is 81.3 years. The prevalence of dementia is related to aging, from 60 to 64 years is 0.6%; 65 to 69 years is 1.3%; 70 to 74 years is 3.3%; 75 to 79 years is 8%; 80 to 84 years is 12.1%; 85 to 89 years is 21.9%, and older than 90 years is 40.8%.4 In Europe, the number of people living with dementia is estimated to be 9,780,678: 6,650,228 women and 3,130,449 men, representing 1,9% of the total population. The number of people with dementia in Europe will nearly double by 2050, increasing to 18,846,286.⁴

Cataracts by the numbers

Cataracts are the number one cause of preventable blindness, causing worldwide advanced vision loss in 65.2 million people and blindness in 20 million. Their prevalence increases with age, ranging from 4% at ages 55 to 64 to 92% at age 80 and older. Cataract surgery is the most effective and common procedure in all medicine. More than 30 million people undergo the surgery every year.⁵

Europe has a population of more than 513.5 million, performing annually 4.7 million cataract surgeries. Different areas and countries have different demographic distributions and access to surgery, realities, and resources. Most countries performed 1.000 surgery or more per 100.000 inhabitants, but others were doing less than 400 surgeries,⁶ which is a significant disparity. (Figure 1)

Cataract removal to reduce dementia

Lee studied prospectively 3038 adults 65 years or older with cataracts and followed up until the development of dementia. The patients who received cataract surgery had 30% less risk of dementia for 10 years.⁷

Cataract surgery can improve symptoms of dementia by enhancing visual acuity and secondary visuospatial orientation-related dementia test results. In addition, patients with dementia and poor vision often have a more active lifestyle after cataract surgery. Patients previous to cognitive impairment and with it may benefit in the short and long term. Assessing the visual function of patients is a key factor, and considering cataract surgery when appropriate may help reduce the risk of dementia.^7-10 Considering the benefits of cataract surgery, even in dementia, it is critical to do more research on the topic, evaluate big data and make cost-analysis cases.

There is much work to do to prevent dementia. Forty percent of dementia cases are preventable considering numerous factors, including correcting sensory impairments, having social connections, good education, regular physical activity, reducing obesity and diabetes, BP control, reducing air pollution, preventing head injury, limiting alcohol and avoiding smoking.¹¹

It is considered that 1.8% of dementia cases are associated with vision impairment.¹² Eighty-percent of vision impairment occurs in adults aged 50 years and older, and 90% of cases are preventable, with cataracts being a crucial factor.¹³ With this evidence, we have more reasons to promote cataract surgery in the older population with dementia risk.

Cataract surgery on time is an efficient option for our patients to facilitate an independent life, better care and fewer costs. From the public healthcare perspective, the cost of the operation is minimal compared with the costs of dementia, that range from 2,687 EUR to 15,468 EUR per individual every year.¹⁴ Public authorities have to be aware of the importance of cataract surgery to benefit patients and communities and offer more resources.

Francesc March de Ribot, MD, PhD, FEBO

E: march.professor@gmail.com

March de Ribot is an ophthalmology consultant at Girona and Otago University, Spain. He has no relevant financial disclosures.

Alper Bilgic, MD, FEBO

E: drbilgicalper@yahoo.com

Dr Bilgic is an ophthalmology consultant at Alpha Vision Augenarzt Practice in Bremerhaven and Dorum, Germany. He has no relevant financial disclosures.

References

1. WHO. Global action plan on the public health response to dementia 2017 – 2025. ISBN: 978-92-4-151348-7

2. Arvanitakis Z, Shah RC, Bennett DA. Diagnosis and management of dementia: review. JAMA. 2019;322(16):1589-1599.

3. Watt JA, Goodarzi Z, Veroniki AA et al. Comparative efficacy of interventions for reducing symptoms of depression in people with dementia: systematic review and network meta-analysis. BMJ. 2021;372:n532.

4. Prevalence of Dementia in Europe. 2019. Accessed January 4, 2023. https://www.alzheimer-europe.org/dementia/prevalence-dementia-europe

5. Liu YC, Wilkins M, Kim T, Malyugin B, Mehta JS. Cataracts. Lancet. 2017;5;390(10094):600-612.

6. Eurostat data. Accessed January 4, 2023. https://ec.europa.eu/eurostat/web/products-eurostat-news/-/ddn-20191204-1

7. Lee CS, Gibbons LE, Lee AY, et al. Association between cataract extraction and development of dementia. JAMA Intern Med. 2021:e216990.

8. Chen SP, Bhattacharya J, Pershing S. Association of vision loss with cognition in older adults. JAMA Ophthalmol. 2017;135(9):963-970.

9. Zheng DD, Swenor BK, Christ SL et al. Longitudinal associations between visual impairment and cognitive functioning: the Salisbury Eye Evaluation study. JAMA Ophthalmol. 2018;136(9):989-995.

10. Tamura H, Tsukamoto H, Mukai S et al. Improvement in cognitive impairment after cataract surgery in elderly patients. J Cataract Refract Surg. 2004;30(3):598-602.

11. Livingston G, Huntley J, Sommerlad A et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet. 2020;396(10248):413-446.

12. Ehrlich JR, Goldstein J, Swenor BK et al. Addition of vision impairment to a life-course model of potentially modifiable dementia risk factors in the US. JAMA Neurol. 2022;79(6):623-626.

13. GBD 2019 Blindness and Vision Impairment Collaborators; Vision Loss Expert Group of the Global Burden of Disease Study. Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study. Lancet Glob Health. 2021;9(2):e144-e160.

14. Meijer E, Casanova M, Kim H, Llena-Nozal A, Lee J. Economic costs of dementia in 11 countries in Europe: Estimates from nationally representative cohorts of a panel study. Lancet Reg Health Eur. 2022;20:100445.