Conditions Treated · Cataract Surgery

Cataract Surgery

Written by Mr Robert Henderson BSc MBBS MD FRCOphth · Consultant Vitreoretinal Surgeon, Moorfields Eye Hospital & GOSH

What is a Cataract?

The natural lens of the eye sits behind the iris and is normally crystal clear, focusing light precisely onto the retina. A cataract occurs when this lens becomes cloudy, scattering incoming light and causing progressive visual deterioration. The process is usually gradual, and many people are unaware of a cataract until it has advanced considerably.

Age-related cataract is by far the most common type, affecting the majority of people to some degree by their seventies. However, cataracts can also develop as a consequence of eye disease, previous eye surgery, medications (particularly long-term steroids), systemic conditions such as diabetes, trauma, or — in children — as a congenital condition present from birth.

Symptoms of Cataract

• Gradual blurring or haziness of vision
• Increased glare from lights, particularly when driving at night
• Colours appearing faded or yellowed
• Frequent changes in glasses prescription
• Monocular double vision
• Difficulty reading in low light

In children, cataract may present differently — with a white pupil (leukocoria), a squint, or abnormal eye movements. Congenital and early childhood cataract requires urgent assessment, as prompt treatment is essential to prevent amblyopia (lazy eye) and allow normal visual development.

Cataract Surgery: The Procedure

Phacoemulsification

Modern cataract surgery uses a technique called phacoemulsification, in which the cloudy lens is broken up using ultrasound energy and aspirated through a small incision of approximately 2.2–2.8mm. A foldable artificial intraocular lens (IOL) is then implanted in the capsular bag — the natural envelope that held the original lens. The incision is self-sealing and requires no sutures in the vast majority of cases.

The procedure is performed under topical anaesthesia (eye drops alone) or local anaesthesia, as a day case. A standard cataract operation typically takes around 10 to 12 minutes, and patients are comfortable throughout. Vision often improves within 24 hours, with full recovery over a few weeks.

Lens Choice

There is now a wide range of intraocular lens options available, and the choice of lens is an important part of the preoperative discussion. Options include monofocal lenses (correcting distance or reading vision), extended depth-of-focus lenses, and multifocal lenses offering a range of focal distances. The optimal choice depends on your visual requirements, lifestyle, and the health of your retina — a consideration that is particularly important in patients with pre-existing macular or retinal conditions.

Complex Cataract Surgery

A significant proportion of my cataract practice involves complex cases that require advanced surgical skills and judgment. These include:

Post-Vitrectomy Cataract

Cataract formation is one of the most predictable consequences of vitrectomy surgery — within one to two years of vitrectomy, virtually all patients who retain their natural lens will develop a visually significant cataract. This is a well-recognised and manageable consequence of retinal surgery, but it requires careful planning. The vitrectomised eye behaves differently during phacoemulsification — the absence of vitreous support alters the dynamics within the eye and demands specific surgical adaptations to ensure a safe and successful outcome.

Combined Phacovitrectomy

In many cases, it is advantageous — and more efficient for the patient — to perform cataract surgery and vitrectomy as a single combined procedure (phacovitrectomy). This approach is commonly used when a patient has both a visually significant cataract and a retinal condition requiring vitrectomy, such as an epiretinal membrane, macular hole, or tractional retinal detachment. Combining the procedures eliminates the need for two separate operations and reduces the overall recovery period.

Subluxated Lens and Dropped Nucleus

Subluxation refers to partial dislocation of the natural lens from its normal position, which can occur due to trauma, connective tissue disorders such as Marfan syndrome, or as a complication of previous surgery. Managing a subluxated lens — or a lens nucleus that has dropped into the vitreous cavity during cataract surgery — requires vitreoretinal surgical expertise. These cases are ideally managed by a surgeon with dual competency in anterior segment and vitreoretinal surgery, allowing the entire problem to be addressed in a single operative setting.

Paediatric Cataract Surgery

Cataract in children is a very different clinical entity to age-related cataract in adults, and its management is correspondingly more complex. As Clinical Lead for Ophthalmology at Great Ormond Street Hospital — the UK’s leading children’s hospital — I have extensive experience in the surgical and medical management of paediatric cataract. Paediatric cataract surgery is performed at GOSH, where the full infrastructure of a world-class children’s hospital supports every aspect of care, from anaesthesia to postoperative follow-up.

The primary goals of paediatric cataract surgery are to remove the optical obstruction and restore a clear visual axis, and then to support normal visual development through appropriate optical correction (glasses or contact lenses) and treatment of any associated amblyopia. General anaesthesia is required for all children undergoing cataract surgery.

Key considerations specific to paediatric cataract include:

• Timing — dense cataracts present from birth require urgent surgery, ideally within the first weeks of life, to prevent irreversible amblyopia
• Posterior capsule management — children’s eyes have a far greater tendency to develop posterior capsule opacification than adults, and specific surgical techniques are required to address this
• IOL implantation — the decision whether to implant a lens at the time of surgery depends on the child’s age and eye size; very young infants are often left aphakic and corrected with contact lenses initially
• Amblyopia treatment — surgery is only the beginning; dedicated follow-up and patching therapy are essential to maximise visual potential
• Associated conditions — paediatric cataract is often associated with other ocular or systemic conditions that require coordinated, multidisciplinary management

Private Cataract Surgery in London

Private cataract surgery for adults is currently available at Moorfields Eye Hospital — the world’s oldest and most respected specialist eye hospital, and the institution where I hold my NHS consultant post. From September 2026, the majority of my adult private surgical practice will move to 1 Welbeck, Marylebone — a state-of-the-art private hospital in the heart of central London — which will become the principal centre for my private practice. Patients can be confident that the same surgical standards apply at both sites.

For patients requiring combined cataract and vitrectomy surgery, or those with complex ocular histories, being assessed and operated on by a vitreoretinal surgeon with full anterior segment competency provides an important safeguard — should any complication arise, it can be managed immediately by the same surgeon without the need for referral.

When Should I See a Surgeon?

Cataract surgery is elective — it is performed when the visual impairment is affecting your quality of life, not simply because a cataract is present. There is no advantage to waiting until vision is severely reduced. If you are finding that your vision is affecting your driving, reading, or daily activities, or if you have been told you have a cataract and would like an expert opinion, I would be very happy to see you.

For children, any concern about a white pupil, squint, or visual inattentiveness should prompt urgent referral — do not wait for a routine appointment.

Mr Robert Henderson BSc MBBS MD FRCOphth is a Consultant Vitreoretinal Surgeon at Moorfields Eye Hospital and Great Ormond Street Hospital, and Clinical Lead for Ophthalmology at GOSH