Falls and dementia in the elderly – is cataract surgery part of the solution?

This article was prepared by Dr Sheck's research assistant and approved by Dr Sheck.

Age-related health issues, such as cataracts, dementia and falls, can have a debilitating effect on an elderly person’s quality of life. In particular, vision impairment can reduce a person’s ability to perform self-care tasks and increase their risk of falls, fractures, and cognitive decline. Cataracts, a common eye condition characterised by the clouding of the lens, affects 20% of people aged over 65 and is the leading worldwide cause of preventable blindness and low vision. Cataract surgery represents a beneficial and cost-effective treatment option for restoring vision acuity and reducing the risk of falls in the elderly. Additionally, recent research has reported a compelling link between cataract surgery and cognitive function, with those patients undergoing cataract surgery having a 30% reduced risk of developing dementia.

Cataract surgery in New Zealand

Despite being deemed a highly successful surgery with a low complication rate, access to cataract surgery remains limited in New Zealand. Compared to similar Organisation for Economic Co-operation and Development (OECD) countries, cataract surgery in New Zealand is often performed on patients with lower vision and more advanced cataracts due to limited resources and a lack of funding. The threshold for patients to receive publicly funded surgery in New Zealand is also restrictive, with a mean visual acuity of 6/30 (corresponding to 20% perfect vision) required before becoming eligible, although the Auckland region tends to refer patients prior to this threshold being reached. Consequently, patients present with advanced cataracts at the time of surgery, raising the risk of surgical complications. Moreover, patients may have experienced a significant deterioration in their quality of life prior to surgery. It is also worth noting that Māori and Pacific Island populations typically present at a younger age and with worse visual acuity at the time of surgical assessment than their NZ European counterparts. Geographical disparity is a further consideration. Te Whata Ora Health New Zealand set their own eligibility thresholds, and the absence of a nationwide threshold leads to regional variation in access to publicly funded cataract surgery.

Dementia in New Zealand

In New Zealand, dementia affects 8% of people aged over 65 years, with Māori and Pacific Island populations having disproportionately higher rates and earlier onset, when compared to NZ Europeans. The prevalence of dementia is set to increase over the coming decades due to our ageing population, and with it, an increase in the associated economic costs, which are currently running at NZ$3.6 billion/year. No curative treatments exist for dementia, so it is even more important to find ways to reduce disease risk or delay disease onset. 

Can cataract surgery lower the risk of dementia?

Vision impairment is recognised as an important risk factor for dementia, with vision loss increasing the odds of dementia by nearly 3-fold. With cataracts being the primary cause of vision loss, the recent study published in JAMA Internal Medicine linking cataract surgery with a reduced dementia risk is particularly relevant. This was a prospective cohort study examining the rate of dementia in over 3000 participants with cataracts aged over 65 years. Cataract surgery was performed on half the study population (46%), and these patients were found to have a 30% lower risk of developing dementia over a 10-year period (hazard ratio, 0.71; 95% CI, 0.62-0.83; P<0.001). The reasons underlying this reduction in risk are yet to be fully elucidated; however, it is thought that restoring sensory stimulation to the brain via cataract surgery is a major contributing factor. Improving an individual’s vision so that they can re-engage with social and physical activities is also thought to help protect against cognitive decline in the elderly. 

Can cataract surgery reduce the risk of falls in the elderly?

Vision impairment is well recognised as a contributing factor to the risk of falls in the elderly, and patients with cataracts have nearly a 3-fold increase in the risk of falls. Falls can result in adverse events, such as hip fractures and head injuries, and falls associated with hospitalisations increase the likelihood of nursing home admissions and can lead to a decline in overall health. Interventions that can reduce the risk of falls are an important health initiative to preserve the health and well-being of the older population. As demonstrated by a recent meta-analysis, surgery provides an effective solution for those patients with cataracts, reducing the risk of falls by one-third. A study published by the New Zealand Medical Journal favours cataract surgery as a cost-effective treatment option for preventing falls in patients with cataracts.

Some final thoughts

Many of my patients are reluctant to undergo cataract surgery, viewing themselves as too old or not wishing to go through the perceived hassle of cataract removal. However, cataract surgery is considered a routine, safe and effective surgery for restoring vision impairment associated with cataracts. Surgery may improve an individual’s balance, gait and overall mobility, creating an overall better quality of life. Coupled with evidence that cataract surgery can reduce a patient’s risk of dementia and falls, surgery is an attractive intervention with many benefits when looking to preserve the wellbeing of our elderly population. Age should not be perceived as a barrier to undergoing this potentially transformative surgery.  

About Dr Leo Sheck

Dr Sheck is a RANZCO-qualified, internationally trained ophthalmologist. He combined his initial training in New Zealand with a two-year advanced fellowship in Moorfield Eye Hospital, London. He also holds a Doctorate in Ocular Genetics from the University of Auckland and a Master of Business Administration from the University of Cambridge. He specialises in medical retina diseases (injection therapy), cataract surgery, ocular genetics, uveitis and electrodiagnostics.