When it comes to cataract surgery, most people think it’s a fairly straightforward, high-success procedure. And in many cases, it is. But if you’re someone with a high body mass index (BMI)—specifically in the morbidly obese category—the experience can be quite different. This doesn’t mean you can’t have a successful outcome. It simply means your surgeon and anaesthetist need to make careful adjustments to ensure your safety and comfort throughout the process.
In this article, we’ll walk through the key concerns, adaptations, and evidence-based approaches that eye surgeons and anaesthesia teams use to provide the best possible care for patients with morbid obesity. Whether you’re a patient, carer, or medical professional, this guide should give you a clearer understanding of what’s involved.
Understanding Morbid Obesity and Cataract Surgery
Let’s begin with what we mean by “morbid obesity.” A person with a BMI of 40 or above falls into this category. It’s more than just a number—it reflects significant physiological changes that can influence many aspects of surgery. For ophthalmologists, performing a micro-precision procedure like cataract extraction becomes more complex due to body habitus, positioning limitations, and risks related to sedation.
The lens of the eye is still the target, but everything surrounding that—how the patient is positioned, how the airway is managed, how long the procedure takes—can be different. These added layers of complexity require thoughtful preoperative planning and customised equipment.
The Role of BMI in Surgical Ergonomics and Theatre Setup
One of the first challenges that arises when performing cataract surgery on a morbidly obese patient is the layout of the surgical theatre. The surgeon, microscope, operating table, and support staff all need to work within a very defined space. When body mass significantly limits table height, access, or reach, this can disrupt surgical ergonomics.
Operating microscopes are typically adjusted for specific eye-to-table distances. If a patient’s abdominal girth or chest size raises them higher on the table, the microscope might not have enough clearance or reach to focus properly. This might sound like a minor issue, but it can have serious consequences for the surgeon’s posture, visibility, and ultimately surgical accuracy.
To address this, some surgical units use custom bariatric operating tables that can be lowered further than standard tables and support higher weight loads. These modifications ensure that patient safety isn’t compromised while allowing the surgeon to work in a posture that minimises fatigue and enhances precision.
Positioning the Patient: Comfort, Access, and Airway Considerations
One of the most critical stages of cataract surgery is patient positioning. Standard cataract procedures are done with the patient lying flat in the supine position. But for patients with morbid obesity, lying flat for an extended period may be very uncomfortable or even dangerous. Large abdominal weight can press against the diaphragm, making it harder to breathe. If there’s associated obstructive sleep apnoea or respiratory compromise, the risks multiply.
In such cases, a reverse Trendelenburg position may be used. This involves tilting the upper body slightly upwards, reducing pressure on the chest and diaphragm and helping improve ventilation. The challenge, though, is that the eye still needs to be positioned appropriately for surgical access, so headrests and customised foam padding are often used to create the right angle.
The head and neck positioning must also allow for safe airway access. A flatter face angle can sometimes obscure the surgical view under the microscope, so the surgeon must work closely with the anaesthesia team to strike the right balance between airway security and ocular exposure.
Airway Management and Sedation Protocols
Most cataract surgeries are done under local anaesthesia, often with mild sedation. But in patients with morbid obesity, sedation can be riskier. Obesity affects how sedatives are distributed, metabolised, and cleared from the body. Plus, there’s an increased likelihood of airway collapse, especially in individuals with obstructive sleep apnoea.
The anaesthesia team must evaluate the airway thoroughly in advance. This may include assessing for a short neck, limited neck mobility, large tongue, and Mallampati score—all of which can predict difficulty in ventilation or intubation if general anaesthesia becomes necessary.
Some hospitals opt for monitored anaesthesia care (MAC) instead of full general anaesthesia in such cases. With MAC, the patient remains conscious but relaxed, and the anaesthetist remains prepared for rapid airway intervention if needed. Oxygen delivery is optimised, and careful dosing helps avoid over-sedation. It’s a balancing act between providing comfort and preserving airway control.
Challenges with Ocular Access and Surgical Angles
Apart from patient positioning, the actual act of reaching the eye during surgery may also present challenges. For patients with large chests or facial adiposity, the surgeon’s field of view may be limited. Additionally, large cheeks or periorbital fat can make it harder to retract the eyelids or properly insert surgical instruments.
To compensate, surgeons often use longer surgical instruments and specula designed specifically for deeper orbital access. Adjustable headrests and positioning pads can also be used to bring the eye closer to the plane of the microscope. In some extreme cases, surgeons may need to angle their instruments slightly more vertically than usual, which demands an even steadier hand and more careful control to avoid complications like posterior capsule rupture.
Preoperative Considerations and Systemic Risk Assessment
Before any surgical intervention, thorough preoperative screening is essential. This becomes even more important in patients with morbid obesity due to the higher incidence of co-morbidities like:
- Hypertension
- Type 2 diabetes
- Cardiovascular disease
- Obstructive sleep apnoea
- Fatty liver disease
All of these can affect healing, increase anaesthetic risk, or influence medication dosing. Blood sugar levels must be optimised, blood pressure stabilised, and any cardiac concerns investigated before surgery is scheduled. A detailed anaesthetic consult is non-negotiable.
In some cases, a multi-disciplinary approach is taken, involving the patient’s GP, endocrinologist, and respiratory specialist. A well-rounded assessment ensures that any hidden risks are surfaced and accounted for before entering the operating theatre.
The Role of Bariatric-Friendly Equipment
Not all surgical theatres are equipped to handle the specific needs of bariatric patients. Apart from adjustable operating tables, wider and reinforced surgical chairs are also required for postoperative assessments. Some ophthalmic units now stock:
- Heavy-duty surgical stretchers and wheelchairs
- Extra-wide theatre gowns and blood pressure cuffs
- Reinforced phacoemulsification handpieces
- Adjustable head stabilisers
These may sound like minor upgrades, but they make a major difference in delivering dignified, efficient care. Without them, patients may feel neglected or at risk due to inadequate support structures.
Surgical Time and Anaesthetic Window
Cataract surgeries are typically short procedures, often completed within 15 to 30 minutes. But in patients with difficult positioning, challenging anatomy, or obstructive airway risk, the total operating time can increase. This prolonged surgical time places greater emphasis on minimising movement and maintaining oxygen saturation.
Surgeons must work efficiently yet cautiously, especially if sedation windows are tight. In some cases, a “standby” anaesthetist may be present solely to monitor airway status, allowing the surgeon to focus solely on the eye.
Postoperative Recovery and Healing Concerns
Healing after cataract surgery is typically smooth. But in patients with morbid obesity, delayed wound healing and higher inflammation markers may slow the process. There’s also a higher risk of subconjunctival haemorrhage and bruising around the eye, especially if anticoagulants or antiplatelet drugs are being taken for cardiovascular reasons.
Antibiotic drops are still effective, but systemic absorption and metabolism may be slightly altered. So careful follow-up and adherence to a tailored postoperative plan become essential. Some surgeons may choose longer courses of anti-inflammatory drops or arrange earlier follow-up visits to monitor healing.
Psychological Readiness and Patient Expectations
There’s another layer to consider here: how the patient feels about undergoing surgery. People with morbid obesity often report negative experiences in healthcare settings. They may be anxious, fearful of judgement, or worried about the logistics of moving through the clinic environment.
Surgeons and staff must approach these patients with empathy, clear communication, and practical reassurances. Walking them through what to expect at each stage, addressing mobility concerns, and providing reassurance that the team is well-prepared for their needs can make a world of difference.
FAQs: Cataract Surgery in Morbidly Obese Patients
- Is it safe to have cataract surgery if I am morbidly obese?
Yes, cataract surgery can be performed safely in morbidly obese patients as long as specific precautions are taken. Surgeons adjust equipment, positioning, and anaesthetic plans to account for your physiology, ensuring your safety and comfort throughout the procedure. - Will I need general anaesthesia for cataract surgery due to my size?
In most cases, general anaesthesia is not necessary. Many patients with morbid obesity can still undergo the procedure with local anaesthesia and light sedation, but your anaesthetist will assess your airway and overall health to make the safest recommendation. - What special equipment is used for morbidly obese patients?
Hospitals may use bariatric-friendly operating tables that support higher weights, longer surgical instruments, wider stretchers, reinforced surgical chairs, and adjustable headrests to make the experience safe and effective for patients with larger body sizes. - Can obesity affect how well I heal after cataract surgery?
Yes, obesity can slightly delay healing due to factors like chronic inflammation, higher rates of diabetes, and circulation issues, but this risk is manageable with personalised postoperative care, appropriate use of drops, and early follow-up appointments. - What should I tell my surgeon before the procedure?
You should inform your surgeon and anaesthetist about any breathing issues, history of sleep apnoea, medication use, mobility concerns, or chronic health conditions so they can plan the surgery around your specific needs and minimise any potential complications. - Will I be able to lie flat during the surgery?
Not always — many patients with morbid obesity struggle to lie flat due to breathing discomfort or pressure on the chest and diaphragm. In such cases, the surgical team may position you in a reverse Trendelenburg tilt or use specialised padding and headrests to keep you comfortable and still ensure access to the eye. - Does my weight increase the risk of surgical complications?
Your weight alone doesn’t necessarily increase the risk of complications directly related to the eye surgery itself, but it can introduce additional considerations such as airway management, positioning challenges, and systemic health factors that require careful planning and monitoring. - How does sleep apnoea affect cataract surgery planning?
Sleep apnoea, which is common in morbidly obese patients, can increase the risk of airway obstruction during sedation. Your anaesthetist will take this into account when planning your sedation strategy and may opt for monitored anaesthesia care with continuous oxygen support to maintain airway safety throughout the procedure. - Will I be treated differently because of my weight?
You should not be treated with any less care or respect because of your weight. Reputable clinics and surgical teams are trained to accommodate patients of all sizes with sensitivity and professionalism, using appropriate equipment and ensuring that you are physically and emotionally supported throughout your care. - Can both eyes be done at once if I have morbid obesity?
Immediate sequential bilateral cataract surgery (operating on both eyes on the same day) may be an option for some patients but must be considered carefully in the context of your weight, anaesthetic risk, and general health. Your surgeon will weigh up the risks and benefits and may recommend staged surgery if safety is a concern. - Should I lose weight before cataract surgery?
Weight loss can have long-term health benefits, but it’s not usually a prerequisite for cataract surgery unless your surgeon or anaesthetist identifies specific concerns that would make the procedure unsafe. Instead, the focus is typically on managing existing health conditions and ensuring the surgical environment is properly prepared for your needs.
Final Thoughts
Cataract surgery in patients with morbid obesity isn’t about “complication”—it’s about adaptation. When clinicians take the time to understand each patient’s unique needs, they can deliver excellent outcomes, even in more complex surgical environments. With proper positioning, safe anaesthesia protocols, and the right equipment, surgery can be performed just as safely as in other patient groups.
If you’re someone facing cataract surgery and you fall into this category, don’t hesitate to ask your surgeon about their experience and the steps they’ll take to keep you safe. It’s your right to feel informed and confident about your care.
References
- Wynn‑Hebden, A. & Bouch, D.C. (2020) ‘Anaesthesia for the obese patient’, BJA Education, 20(11), pp. 388–395. Available at: https://pubmed.ncbi.nlm.nih.gov/33456923/ (Accessed: 26 June 2025). (pubmed.ncbi.nlm.nih.gov)
- Bellamy, M. & Struys, M. (2017) Anaesthesia for the Overweight and Obese Patient, Oxford University Press, Oxford. Available at: https://www.bjanaesthesia.org.uk/article/S0007-0912(17)35981-0/fulltext
- NYSORA (2023) ‘Obesity’, NYSORA Anesthesia Resources. Available at: https://www.nysora.com/anesthesia/obesity/
- Wikipedia (2025) ‘Total intravenous anaesthesia’, Wikipedia. Available at: https://en.wikipedia.org/wiki/Total_intravenous_anaesthesia