Cataract surgery & refractive lens exchange


Cataract surgery is one of the most frequently performed elective medical procedures. Surgery is typically performed as a day case, is not painful and recovery is rapid. During surgery a new lens is placed within the eye called an intra-ocular lens or IOL. David Anderson completed an 18-month Fellowship in cataract surgery at Moorfields Eye Hospital and has performed many thousands of surgeries particularly for patients with high spectacle corrections, complex cataracts and following other types of refractive surgery. He teaches cataract surgery to Fellows from the UK and internationally and instructs in microsurgical skills for the Royal College of Ophthalmology.

Animation explaining cataract surgery


What is the lens?The lens in the eye

The lens is the part of the eye that helps focus light on the retina (just like the lens in a camera). The lens is made of a clear, jelly-like substance.  The retina is the eye’s light-sensitive layer that transmits visual signals to the brain (like the photographic film in a camera), to help produce a sharp image, the lens must remain clear and flexible.

What is a cataract?

A cataract is a clouding or frosting of the lens of the eye, which is most commonly age related. Other causes include trauma to the eye, diabetes, drugs such as steroids, and cataracts can also be inherited.

As we age the clear crystalline lens can start to harden and enlarge leading to presbyopia (difficulty with near vision). If a cataract develops the vision gradually deteriorates, a similar effect to that of looking through frosted glass. At this stage a new glasses prescription will not be able to correct your vision.

When does a cataract require treatment?

With modern surgical techniques it is possible to operate on a cataract at a relatively early stage, they do not need to be mature or ‘ripe’. There is no specific level of vision at which cataract surgery is indicated, but it is usually recommended if the quality of your vision is reduced such that is affecting your lifestyle. Surgery is also indicated if you wish to drive and your vision no longer meets the necessary DVLA legal standard.

Refractive cataract surgery and refractive lens exchange (RLE)

Accurate measurements of the eye taken prior to surgery allow an IOL to be implanted which can correct for long or short sightedness and astigmatism so that as well as clear vision, vision can be optimized without the need to wear spectacles for normal distance vision. Prior to the development of cataract, surgery to replace the lens can be employed to improve the vision by implanting an IOL which can correct for a high spectacle prescription, this procedure is known as RLE.

To improve the range of vision and depth of focus, multifocal lens implants can be used to reduce the requirement for reading spectacles as well as provide clear vision for distance visual tasks e.g. driving or watching the television. Although spectacles may still be required for some visual tasks, many patients rarely require spectacles after this form of surgery.

What does the surgery involve?

On the day of surgery and once in the hospital you will be given eye drops to dilate the pupil. The area around your eye will be washed and cleansed. The operation usually is usually performed under a local or topical anaesthetic, is painless and lasts 15-20 minutes in most cases.  The technology used is called phaco-emulsification and employs ultrasound energy to liquefy the lens which can then be aspirated. A new lens is then inserted using an injection system and is unfolded and positioned within the eye. We no typically do not use stitches during surgery which allows for a faster recovery.

After the operation you will rest for a while and have refreshments then you can go home. You will be given a dressing pack to swab the eye clean the following day, and some antibiotic and anti-inflammatory eye drops to apply at home after the surgery.

You will need to allow 3-4 hours for your hospital stay so that we can run through your treatment and aftercare with you. You will need someone to collect you or we can arrange transport for you.

Timing of sequential cataract surgery

Surgery will normally take place with an interval of one week or less between each cataract surgery procedure.

How quickly will my vision be restored?

Your vision will be slightly blurred for a few days while your eye heals. It is not uncommon to feel some discomfort, usually a feeling that something is in the eye until your eye settles but there should be no pain.  After a couple of days you will start to notice a significant improvement in your vision.  You can quickly return to many everyday activities, although heavy lifting or other strenuous activities should be avoided for a week. The healing eye needs time to adjust so that it can focus properly with the other eye, especially if the other eye has a cataract. Ask your surgeon or optometrist when you can resume driving.  You will see the surgeon again after 2 weeks and will visit your optometrist for new glasses after 6 weeks.

Once you have been given your new glasses, you may notice that everything seems a lot brighter than you remember. Colours may be sharper and may have a blue-ish tinge. In bright sunlight you may feel you are looking through rose-coloured glasses. These colour tinges are normal and are because you are now looking at the world through a clear lens that is no longer cloudy. Within a few months your brain will get used to your new clear vision and these colours should go away.

Femto Laser Assisted Cataract Surgery (FLACS)

Lasers can now be used to complete some stages of cataract surgery with extra precision. This includes the entry incisions, capsulorhexis and softening or fragmenting the nucleus. These lasers use very short pulses (femtosecond) of energy which create tiny gas bubbles and employ the same principles that we have been using in LASIK for some years.

David Anderson co-authored a review of FLACS published in the scientific journal Eye Nature in 2013, to read please follow this link.

What are the risks of cataract surgery?

David Anderson has performed many thousands of cataract operations. We ensure that the technology and products used for the surgery are of the highest standards available. We operate using state of the art equipment with facilities for sedation and general anaesthesia if required.

Although the vast majority of patients achieve excellent results without complications, it should not be forgotten that cataract removal is a surgical procedure. As with all forms of eye surgery, cataract removal has risks and whilst we make every effort to minimise them they cannot be totally eliminated.

Although rare, the most common risks include:

  • Retinal Detachment:- this is when the interior surface of the back of the eye (the retina) becomes detached from the wall of the eyeball.  If surgical correction is not successful it can result in severe loss of vision.  The risk is increased for highly myopic patients.
  • Infection:- Whenever an incision is made in the eye it is possible to contract an infection which could potentially cause visual loss.  Due to the quality of our hospital theatre environment and our surgeon’s skill, this is extremely rare.  As an added precaution we prescribe antibiotic eye-drops for compulsory use after the operation.
  • Macular Oedema:- This is an accumulation of fluid at the central retina which can cause a temporary or permanent reduction in vision after surgery.  The drops we prescribe reduce the risk of this occurring.
  • Floaters:- These floating objects are often experienced after surgery but usually settle over time.
  • Other complications:- tearing of the lens capsule which can make it difficult or impossible to position the lens implant; bruising around the eye or double vision resulting from local anaesthesia; a temporary increase in the intra-ocular pressure.

How long will the implanted IOL last?

The IOL implants are usually left in place for life, they are biologically inert and are made from acrylic polymers.

Lens implant choice

The natural crystalline lens in childhood has the consistency of a deformable gel. This flexibility allows it to change shape and therefore change focus so that provided the eye is of normal size, vision is clear at all ranges from very close to the horizon. Replacement IOL’s have not yet been manufactured to this level of performance but are able to provide excellent visual outcomes.

Monofocal lens implants

These lenses are optimised for visual performance at distance e.g. driving or watching the television. Reading glasses are required for close work. These lenses can also be used to minimize pre-existing corneal astigmatism. By varying the focal distance between each eye, improved depth of focus can often be achieved to minimize spectacle dependence after surgery.

Multifocal lens implants

These lenses are designed to maximize the range of vision and therefore to minimize dependence upon spectacles after surgery. Many patients can read clearly without spectacles as well as see well at distance. Multifocal lenses however, may produce unwanted effects from light scatter although these are usually minor and well tolerated. Occasionally laser vision surgery is used to enhance clarity of focus after surgery (<2% of patients). Some patients do not tolerate these symptoms and rarely the lenses require removal and replacement with a monofocal lens (<1% of patients).

Can I fly following surgery?

You can fly on the day of surgery but it is advisable to remain local to the hospital for the first few weeks after surgery.