When planning cataract surgery, most people think of it as a fairly straightforward procedure. And in many cases, it is. But if you or a loved one lives with a neurodegenerative disease—like Parkinson’s, multiple sclerosis (MS), or even more advanced dementia—the situation changes. Suddenly, it’s not just about the cloudy lens anymore. It’s about tremors, poor fixation, altered communication, and complex medication regimens. In this guide, we’re going to walk through how cataract surgery is carefully adapted in these neurologically complex cases, and what you can do to prepare and protect your vision.
Understanding the Intersection of Neurology and Ophthalmology
When we talk about neurodegenerative diseases, we’re referring to conditions that involve progressive deterioration of the nervous system. This includes Parkinson’s disease, MS, Huntington’s disease, amyotrophic lateral sclerosis (ALS), and various forms of dementia. What many people don’t realise is that these conditions often have direct or indirect effects on the eyes—even before cataracts become an issue.
For example, patients with Parkinson’s might struggle with reduced blink rate, leading to dry eye symptoms. Those with MS may have optic neuritis or reduced visual fields. And individuals with advanced dementia might not be able to articulate their vision issues at all. So when cataracts come into the picture, the usual surgical planning becomes far more nuanced. It’s about tailoring the procedure not only to the eye, but also to the neurological challenges that could impact the outcome.
Why Cataracts Are Especially Problematic in Neurological Conditions
Cataracts can quietly exacerbate the difficulties already faced by people with neurological illnesses. Visual processing is already compromised in many of these diseases, and any additional barrier—like a cloudy lens—can make communication, mobility, and quality of life even harder.
Take Parkinson’s, for example. Visual contrast sensitivity is often reduced, making it difficult for patients to judge depth or identify objects in low lighting. Add a cataract to the mix, and this impairment can become debilitating. Similarly, MS can cause rapid vision fluctuations, so even subtle cataracts can lead to dramatic swings in visual clarity, confusing both patients and caregivers.
Moreover, vision plays a major role in balance and mobility—already compromised in many neurodegenerative conditions. Cataracts reduce this stabilising input, increasing the risk of falls and accidents. That’s why cataract surgery, while technically elective, becomes clinically important in this context.
Fixation Instability: A Key Surgical Challenge
Fixation stability refers to the eye’s ability to maintain a steady gaze during a visual task. In neurodegenerative patients, this can be significantly disrupted. Parkinson’s disease, for instance, can cause saccadic intrusions—quick, involuntary movements that make it hard for the eye to stay focused. MS may result in nystagmus, a rhythmic oscillation of the eyes that further complicates fixation.
For cataract surgeons, this is a major consideration. Steady fixation is crucial during phacoemulsification (the technique used to break up and remove the cloudy lens). Any sudden eye movement can increase the risk of complications like posterior capsule rupture or zonular dehiscence.
In some cases, the surgeon may need to modify their approach. This could include using iris hooks or capsular tension rings to stabilise the eye, or even converting to a manual extracapsular technique if control is poor. Preoperative planning often involves detailed discussion with the patient and carer about their ability to cooperate during the procedure—and in many cases, this is assessed during biometry or slit-lamp exams.
Managing Tremors and Involuntary Movements
Tremors are common in Parkinson’s, essential tremor, and other movement disorders. While they might not directly affect the eye, they can have major implications for surgery. A hand or head tremor can interfere with positioning during the procedure or compromise the sterility of the surgical field. In some cases, the patient may need mild sedation or physical supports (like neck pillows or limb restraints) to keep them still and comfortable.
Interestingly, some studies suggest that deep brain stimulation (DBS) used in advanced Parkinson’s may reduce ocular tremors, making fixation slightly more stable. However, DBS can also complicate anaesthesia planning, as we’ll see next.
Postoperative care must also factor in tremors. Eye drops may be harder to self-administer, so carers need to be fully briefed. An eye shield may be necessary at night to prevent accidental rubbing or injury.
Ocular Surface Dysfunction: More Than Just Dry Eyes
Many neurological conditions are associated with poor blink rates or incomplete lid closure, which can lead to dry eye syndrome or exposure keratopathy. Parkinson’s patients, for instance, may blink less frequently, reducing the eye’s ability to maintain a healthy tear film. MS patients might have reduced corneal sensation, increasing their risk of unnoticed abrasions.
For cataract surgeons, this means the ocular surface needs to be optimised before surgery. This might involve a short course of lubricating drops, anti-inflammatory drops, or punctal plugs. An unstable tear film can distort biometry readings, which are critical for selecting the right intraocular lens (IOL). Skipping this step could lead to incorrect lens power and a less-than-satisfactory visual outcome.
Postoperative healing is also more vulnerable when the surface is compromised. Special care must be taken to ensure wounds heal properly and inflammation is controlled.
Choosing the Right Anaesthetic Approach
Anaesthesia in neurologically complex patients isn’t always straightforward. General anaesthesia may carry additional risk in patients with Parkinson’s, particularly if they’re on multiple medications like levodopa, MAO-B inhibitors, or dopamine agonists. Some of these drugs can interact poorly with anaesthetic agents, leading to fluctuations in blood pressure, cardiac instability, or even neuroleptic malignant syndrome.
Local anaesthesia—usually a peribulbar or sub-Tenon’s block—is often preferred. It avoids the systemic risks of general anaesthesia and keeps the patient awake, which is ideal if they can cooperate. However, in some cases, tremors, anxiety, or cognitive impairment might make local anaesthesia unsafe or ineffective.
Sedation is a delicate balance. Too little, and the patient may move. Too much, and respiratory function or neurological status may worsen. It’s often best to involve an anaesthetist familiar with neurodegenerative conditions to tailor the approach accordingly.
The Role of IOL Selection in Neurological Patients
While most patients are offered monofocal lenses as standard, there are specific IOL considerations in patients with neurodegenerative conditions. For example, multifocal lenses require excellent visual attention and neuroadaptation, which may be impaired in Parkinson’s or dementia. These lenses split incoming light between multiple focal points and rely on the brain’s ability to adjust—a process that may be compromised in these patients.
Instead, surgeons may opt for monofocal or extended depth of focus (EDOF) lenses that offer a more stable visual experience. Toric lenses can correct astigmatism, but their alignment must remain precise. This can be risky in patients prone to postoperative head rubbing or eye misalignment.
Blue-light filtering lenses are sometimes considered for patients at risk of age-related macular degeneration, which can co-occur with neurodegenerative disorders. But this is still a debated topic and should be decided on a case-by-case basis.
Communication and Consent: Ethical and Legal Dimensions
Cognitive impairment is a key challenge when it comes to informed consent. Patients with dementia, for example, may not fully grasp the risks and benefits of surgery. In these cases, it’s important to involve family members or legally appointed healthcare proxies. The Mental Capacity Act 2005 (UK) provides a legal framework for making decisions on behalf of those who cannot consent.
But even before that point, doctors must gauge a patient’s understanding, repeat key points, and assess retention over time. Tools like the Mini-Mental State Examination (MMSE) can help assess decision-making capacity. Importantly, documentation needs to be meticulous. Every discussion, concern, and decision should be recorded clearly.
Respecting autonomy while ensuring safety can be a delicate line to walk. But it’s one that must be taken seriously in every single case.
Timing the Surgery: Sooner or Later?
There’s a tendency to delay elective procedures in patients with chronic illnesses. But in many cases, this can actually lead to worse outcomes. As neurodegenerative diseases progress, fixation worsens, motor control deteriorates, and cognition declines. If surgery is put off for too long, the window for safe, successful intervention may close.
Early cataract surgery—before these secondary issues worsen—can actually help prolong independence, improve mobility, and reduce carer burden. Of course, this depends on the stability of the underlying neurological condition. But the idea that surgery should always wait is no longer the default. In fact, in some cases, waiting may do more harm than good.
Postoperative Recovery: What to Expect and How to Manage It
Recovery in neurologically complex patients isn’t just about the eye—it’s about the whole system. Slower healing, reduced dexterity, and difficulties following drop regimens can all affect outcomes. Carers must be involved early, not just at discharge. Ideally, a written plan of drop timings, check-up dates, and warning signs should be provided.
Visual hallucinations, though uncommon, can occur postoperatively—especially in patients with Parkinson’s or Lewy body dementia. These may be temporary but can be distressing. Reassurance, documentation, and if needed, neurological input, are key.
Follow-up appointments may need to be more frequent. If transport is difficult, teleophthalmology follow-ups (for non-urgent checks) can be useful, particularly to confirm compliance or assess basic vision.
Coordinating Care with Neurology and Primary Teams
Cataract surgery doesn’t happen in isolation. For patients with neurodegenerative diseases, it should ideally be part of a broader, interdisciplinary care plan. This means working closely with neurologists, GPs, and sometimes physiotherapists or occupational therapists. Medication timing (especially for Parkinson’s), blood pressure control, and mental state monitoring all play a role in pre-op and post-op success.
Multidisciplinary care planning ensures there are no surprises and that everyone is on the same page. A preoperative joint case review is sometimes helpful for complex cases—particularly when general anaesthesia or hospital admission may be required.
FAQ: Cataract Surgery in Neurodegenerative Conditions
- Can patients with Parkinson’s disease safely undergo cataract surgery?
Yes, most patients with Parkinson’s disease can safely have cataract surgery, but the procedure often requires additional planning. Surgeons must account for tremors, reduced fixation ability, and medication timing. The anaesthetic approach is usually local rather than general to reduce risks, and carers are often involved in the postoperative phase to help with eye drop administration and monitoring. Early surgery—before the disease progresses too far—can significantly improve quality of life. - How is cataract surgery adapted for patients with multiple sclerosis (MS)?
For patients with MS, eye movement issues such as nystagmus and reduced vision due to optic neuritis are key considerations. Ocular surface health is often compromised, requiring pre-surgical management with lubricants or anti-inflammatories. Intraocular lens choice is made cautiously, often avoiding multifocal lenses due to potential difficulty with neuroadaptation. Recovery might be slower, and coordination with neurology teams helps manage systemic symptoms and flare-up risk during the perioperative period. - Is general anaesthesia safe for patients with neurodegenerative diseases during cataract surgery?
While general anaesthesia is sometimes necessary, it’s generally avoided if possible due to the increased risks it poses for patients with conditions like Parkinson’s, advanced dementia, or ALS. These risks include respiratory complications, medication interactions, and post-operative confusion or delirium. Most ophthalmic surgeons will opt for local anaesthesia, such as a sub-Tenon’s block, paired with light sedation when needed. Each case is assessed individually, with input from an experienced anaesthetist. - What are the biggest challenges during cataract surgery for patients with dementia?
The most significant challenge is often communication. Patients with dementia may struggle to understand instructions or stay still during surgery. Preoperative discussions around capacity and consent are essential. Surgeons may modify the technique to accommodate fixation problems or anxiety, and additional support is needed post-surgery to ensure the patient doesn’t rub their eyes or miss follow-up appointments. In many cases, carer involvement is critical throughout the process. - Will cataract surgery improve balance and mobility in patients with neurological conditions?
Yes, clearer vision following cataract surgery can enhance balance and spatial awareness, which is especially beneficial for patients with neurological conditions that already impair motor function. For example, Parkinson’s patients often rely on visual cues for stability, and MS patients with visual field deficits may experience fewer navigation difficulties. While surgery won’t reverse the neurological disease, it can reduce fall risk and improve confidence in daily tasks.
Final Thoughts
Cataract surgery in patients with neurodegenerative conditions isn’t business as usual. It requires more planning, more collaboration, and more understanding of the unique ways the brain and eye interact. But when done thoughtfully, it can have an outsized impact—not just on sight, but on independence, confidence, and overall wellbeing.
So if you or someone you care for is dealing with both cataracts and a neurological diagnosis, don’t be discouraged. Speak to your GP, get an ophthalmology referral, and most importantly, ensure you’re working with a team that understands the full picture. If you’re considering undergoing cataract surgery in London with a specialist team experienced in complex neurological cases, we invite you to explore your options with us.
References
- Lichter, P.R. and Musch, D.C., 2020. Managing the ophthalmic complications of Parkinson’s disease. British Journal of Ophthalmology, [online] 104(6), pp.743–748.
- Erro, R., Stamelou, M. and Barone, P., 2016. The eye in Parkinson’s disease: from pathophysiology to clinical practice. Practical Neurology, [online] 16(3), pp.226–232
- Balcer, L.J., Miller, D.H., Reingold, S.C. and Cohen, J.A., 2015. Vision and vision-related outcome measures in multiple sclerosis. Brain, [online] 138(1), pp.11–27. Available at: https://academic.oup.com/brain/article/138/1/11/261759
- Wong, R., 2018. Surgical strategies for cataract in patients with poor fixation and neurological disorders. Eye, [online] 32, pp.1112–1117.
- Nguyen, V., McCluskey, P. and Coroneo, M., 2021. Ophthalmic considerations in neurodegenerative disease: a review of clinical challenges and surgical decision-making. Clinical and Experimental Ophthalmology, [online] 49(8), pp.779–789. doi:10.1111/ceo.13966