Freedom from glasses with Lens-based (IOL) surgery -RajeshDeshmukh

Options for vision correction have evolved by use of premium IOL in patients with dependence on glasses. As a cataract and refractive surgeon, I have spoken a lot about this and would like to share some answers to the common questions I receive about ‘Lens based surgery’.

What is an IOL?

In 1948, Sir Harold Ridley implanted a clear synthetic implant called an intraocular lens (IOL) to treat cataracts. Since then, techniques have progressed from simply treating cataracts to modern-day vision correction or refractive surgery. A cataract is a clouding up of the natural crystalline lens, which ordinarily helps to focus light on the retina. Cataract surgery involves replacing the cloudy natural lens with an IOL. The focusing power of the IOL is used to reduce dependence on glasses after surgery. Lens surgery is now one of the most commonly performed and low-risk procedures in ophthalmology.

An alternative to vision correction without Laser

Refractive Lens Exchange (RLE) and Implantable contact lens (ICL) are two safe and effective surgeries using modern IOL technology that have rapidly changed the landscape of vision correction in recent times. The third is the more established Laser vision correction (LVC), for example, LASIK, which does not require a lens implant but works on surgically remodelling (shaving) the shape of the front surface of the eye called cornea.

RLE is identical to modern cataract surgery where the natural lens is removed and replaced with an IOL. The only difference is that cataract surgery is performed mainly to correct blur caused by a cloudy lens; whereas RLE is performed to reduce the need for glasses or contact lenses.

ICL involves lens implantation in the eye without removing the natural crystalline lens; again to reduce the need for glasses or contact lens.

Types of IOL?

Monofocal IOL This is the standard IOL used in routine cataract surgery offered in the NHS. It has a single focus and the aim is to reduce glasses dependence either for distance or near vision, but not both.

Premium IOL Premium IOL aim to reduce glasses dependence for a wider range of activities, such as distance (driving), intermediate (computer) and near (reading) tasks.

How do modern Premium IOL work to get rid of glasses?

Multifocal/Trifocal: Unlike monofocal IOLs, these are more advanced to provide multiple focal points. The light is split, so some is focused for distance, some for intermediate and some for near. This allows the patient to focus on multiple distances simultaneously. There may be some loss of contrast and patients may experience haloes at night. These symptoms improve with time by processing in the brain called ‘neuroadaptation’.

Extended Depth of Focus (EDOF): These IOLs use new technology to increase the range of focus compared to standard monofocal lenses, but reduce the common visual side effects that come with Multifocal lenses. This enables clear vision from intermediate to far distances and provides functional near vision. The patient might, however, need to wear spectacles for near tasks like reading small print.

Toric IOL: These IOL can correct astigmatism, a condition in which light is unevenly focussed causing blurred vision at all distances. Both Trifocals and EDOF premium IOL’s are available in toric versions to correct astigmatism.

ICL: The EVO ICL is a micro-thin lens placed inside the eye to correct short-sightedness (myopia), far-sightedness (hyperopia) and astigmatism.

If you are suitable for refractive lens surgery, your surgeon will discuss the best option of the IOL for you depending on your age, lifestyle, spectacle prescription etc.

Patient suitability criteria

RLE

45 years or over (exceptions may be considered depending on individual circumstances).
Have a glasses prescription for distance or near vision, or both.
Wish to reduce or eliminate your dependency on glasses or contact lenses.

ICL

18 years or over with stable prescription and wish to reduce or eliminate your dependency on glasses or contact lenses.
Under the age of 40 years and not reliant on reading glasses.
Unsuitable for laser vision correction due to very high prescription.

What are the benefits of lens based surgery?

RLE

4 in 5 patients are completely glasses free with modern premium IOL and 95% of patients are satisfied with the outcome.
RLE eliminates the need for cataract surgery in later life.
It is often preferred to laser vision correction in the retirement age group as early stages of cataract formation is often already present.

ICL

Highly effective in treating very high spectacle prescription in young individuals who cannot be treated with laser vision correction .
‘Additive’ procedure without removal of tissue, so can be reversed.
Unlike LVC, no reshaping your corneal tissue and hence superior quality of night vision and much smaller risk of developing dry eyes following treatment.

What are the alternatives?

LVC has evolved over 30 years and works on changing the curvature and focusing power of the cornea. As performed on the surface, it has the advantage of avoiding intervention inside the eye.
Continuing in spectacles or contact lenses.

What’s in the future?

New research in premium IOL technology is exciting and there are glimpses of a promising future.

Light Adjustable Lens (RxSight) – Refractive power of the IOL can be tweaked after surgery with UV light to achieve the desired focusing.
Perfect Lens - Laser is used to adjust the refractive power of standard IOL once inside the eye.

In Summary, modern IOL implantation, with or without the removal of the natural crystalline lens, is like building your glasses or contact lenses into your eye as opposed to a change in the curvature of the cornea in LVC.

With visual demands of the modern digital lifestyle, lens-based vision correction along with laser treatment form an excellent surgical option for improved quality of life with maximum glasses independence.

Mr Rajesh R Deshmukh
FRCS, CertLRS, PGDip Cataract & Refractive Surgery
Consultant Ophthalmic Surgeon
www.rajeshdeshmukh.co.uk