Illustration of dual-lens cataract surgery (PresbyDuet technique), showing the monofocal IOL in the capsular bag plus a removable add-on lens in the sulcus - performed by Dr Alison Chiu, a leading cataract surgeon in Sydney, Australia.

Innovative Microincisional Cataract Surgery: Dr Alison Chiu’s Pioneering Approach to Reversible Multifocality

At Pure Sight Eye Surgeons, patients benefit from the expertise of world-renowned cataract and refractive surgeon Dr Alison Chiu, whose commitment to excellence continues to shape best practices in microincisional cataract surgery.

In 2015, Dr Chiu became the first cataract surgeon worldwide to perform a reversible dual-lens procedure – now referred to as the PresbyDuet technique – by combining a Rayner monofocal IOL in the capsular bag with a Sulcoflex® multifocal lens in the sulcus.

Why Reversibility Matters: The Clinical Case

The patient was young, bilaterally amblyopic and highly active, with a strong preference for very clear distance vision (such as street-sign recognition and night driving). Although he also wanted near-vision independence, traditional in-bag multifocal IOLs carry a small risk of glare and reduced contrast, and carry higher risk to reverse once implanted.

To preserve long-term visual quality and flexibility, Dr Chiu selected a dual-lens approach:

• a monofocal IOL in the capsular bag
• a secondary multifocal sulcus lens, removable if needed

The visual outcome was excellent and the patient has since referred many family members to Dr Alison Chiu.

What is the Dual Lens Technique?

The dual lens technique, sometimes known as PresbyDuet, uses two intraocular lenses to provide full-range vision while keeping the multifocal component reversible. A monofocal lens is first placed in the capsule to maintain crisp distance vision. A secondary multifocal or trifocal add-on lens is then placed in front of it, providing near and intermediate focus, and can be removed later if necessary.

Dr Chiu now individualises the approach using either the AddOn® (1stQ) or Sulcoflex® (Rayner) depending on each patient’s visual needs and ocular anatomy.

Broader Uses of the Dual Lens AddOn Intraocular Lenses in Cataract Surgery

AddOn intraocular lenses are not only used for reversible multifocality. They can also be used to upgrade vision after standard cataract surgery, particularly in patients who were not offered a premium cataract lens (such as a multifocal or extended-depth-of-focus IOL) at the time of their operation. AddOn IOLs are also an excellent option for correcting residual refractive error after cataract surgery, where the first lens implant didn’t deliver completely clear vision and glasses are still required.

In certain situations – such as patients with macular degeneration or where standard IOL calculations are less predictable due to other ocular pathology– AddOn lenses can even be used to provide additional magnification and custom optical correction. These versatile applications allow Dr Chiu to provide high-precision, individualised cataract surgery and enhance visual outcomes long after the initial procedure. 

Why Patients Choose Pure Sight Eye Surgeons

Patients searching for the best cataract surgeon in Sydney increasingly value advanced cataract surgery techniques that optimise vision without compromising safety. Dr Alison Chiu is a Key Opinion Leader and Key Evidence Leader for 1stQ AddOn IOLs, and is regularly invited to speak internationally on dual-lens and reversible multifocal strategies.

Her goal remains clear: to provide precise, evidence-based solutions tailored to each patient’s lifestyle and long-term visual needs.