Focusing on the Patient with Dementia

Cataract patients often struggle to accurately describe their symptoms at the best of times. So, how can surgeons best manage when patients present with diminished mental function? How can ophthalmologists help as rates of dementia rise?

Cathleen M McCabe MD works with patients living with dementia, many of them in the advanced stages of the disease. With cataract surgery being associated with a 25–30% reduced risk of dementia, she notes that ophthalmologists can play a major role in mitigating the disease’s impact.

“Visual restoration can help support good brain health. We need to assess patients when they present with a cataract. Are they able to participate in decision making?” Dr McCabe said.

“Patients can be very anxious. I like to reassure them that they’re the boss of their eyeball,” she continued. “You should simplify the information you provide depending on the degree of cognitive impairment.”

Two types of characters with cataracts

Cataract patients affected by dementia can be split into two groups, according to Dr McCabe. The first, with early cognitive impairment, may not want to admit to a loss of vision because they fear losing their independence, and family members may prioritise other health issues.

The second group, affected by advanced cognitive impairment, may not be able to communicate loss of function at all. They present unique challenges, especially when it comes to intraocular lenses (IOLs). This means ophthalmologists must rely more on caregivers and family members.

“Patients with cognitive impairment oftentimes have a more restricted environment. They interact more with the intermediate environment than at distance. Often enough, the only time they need to wear glasses is when they’re seeing distance,” Dr McCabe said.

As such, Dr McCabe recommends using monofocal IOLs rather than simultaneous vision IOLs (SVLs), as the latter require more onerous adaptation. She also advises doctors to target emmetropia or mild myopia based on need, and in the case of the latter condition to consider nondiffractive SVLs along with monofocal.

Dementia is not a normal part of ageing

The mistake clinicians and people in general often make is assuming dementia is a normal part of ageing. It is not—it is just more likely to occur with ageing, much like declining vision.

Renate Claasen MD, a consultant in medicine for the elderly, points out that roughly a third of people living with dementia have a visual impairment, and 50% of people with dementia living in care homes have a visual impairment.

“Dementia can lead to social isolation, depression, and physical inactivity, the same as cataracts,” Dr Claasen said. “You can imagine how having both conditions could interact. Dementia isn’t a normal part of ageing, and it needs to be addressed.”

Dementia disrupts the visual signals the brain receives as its ability to process information decreases. With less processable stimuli, patients can start to see faces where none exist, their episodic memory based on vision becomes compromised, and they become significantly more likely to hallucinate.

The impact of these hallucinations in dementia patients is stark: Dr Claasen reported that hallucinations are present in 23% of cases of Alzheimer’s dementia, in 50% of patients affected by Parkinson’s disease dementia, and a staggering 80% of patients suffering from Lewy body dementia.

“We know that people living with dementia have an eightfold higher risk of falls and have a higher risk of injuries due to these falls. If falls result in a hip fracture, people living with dementia do way worse than people without dementia; they’re less likely to regain their walking ability and have a 67% higher risk of mortality,” Dr Claasen said.

“Cataract surgery reduces the risk of falls in older patients by approximately a third. We can’t always treat cognitive problems, but we can try to improve visual ability.”

Peaceful patient, peaceful practice

When it comes to operating on patients living with dementia to improve their vision, Dr McCabe favours minimising sedation use when possible, as this will reduce the risk of delirium. A topical or local anaesthetic should always be preferred, as this reduces the risk of postoperative cognitive dysfunction (POCD).

However, there will be patients for whom a local anaesthetic will not be possible due to the nature of their dementia. Dr McCabe recommended that if the patient exhibits severe dementia and/or agitation, the doctor should consider a general anaesthetic and immediate sequential bilateral cataract surgery (ISBCS).

“With ISBCS, there are fewer visits, a single anaesthesia exposure, and less need for the patient to adapt to the difference between the two eyes. This means there’s less concern for the patient when they’re wondering why one eye is functioning differently from the other,” Dr McCabe said.

“Ensuring a calm environment and providing verbal reassurance to the patient will ensure efficient surgery. I always have someone holding the patient’s hand.”

Issues with compliance also affect the medication stage. Dr McCabe believes it’s best to use tapered treatment regimes and consider using combination drops, and said that ‘dropless drops’—such as subconjunctival triamcinolone, intracameral antibiotics, and phenylephrine/ketorolac infusions—achieve the best results.

“A recent study found that inflammation and complications such as intraocular pressure spikes, changes in macular thickness, or risk of cystoid macular oedema and pain and discomfort were not statistically significantly different for a topical versus a droplet regimen. Patients uniformly liked this regimen better,” Dr McCabe said.

Health is holistic

Throughout it all, one must remember that patients don’t just have dementia, they are living with it. As such, a holistic approach is required, one that incorporates a fundamental understanding of what it’s like to live with the disease.

Dr McCabe is laser-focused on highlighting the importance of tailoring one’s schedule to the needs of patients and their caregivers. Keep things simple with monofocals and droplets, and support and always listen to caregivers.

“You must think about safety with anaesthesia—and eye protection. As for postoperative care, it’s essential to involve the caregivers and family too if you can,” Dr McCabe said. “Then you can consider the visual needs of the patient.”

Dr Claasen has long called for doctors across the medical spectrum to collaborate more closely in treating dementia, and she believes cataract surgery represents an excellent opportunity for greater cooperation.

“It’s good to realise that dementia and visual impairment often coexist and worsen each other’s impact. It’s essential to have a multidisciplinary approach, as this obviously impacts the day-to-day life of patients and their families,” Dr Claasen said.

Drs McCabe and Claasen presented at the 2025 ESCRS Annual Congress in Copenhagen.

Cathleen M McCabe MD is the Chief Medical Officer at Eye Health America, Florida, US. cmccabe13@hotmail.com

Renate Claasen MD is a consultant in geriatric medicine at Cambridge University Hospital, UK. renate.claasen@nhs.net