Clear Lens Extraction

Clear Lens Extraction, also known as Refractive Lens Exchange is a surgical procedure designed to eliminate the need for distance glasses or contact lenses and it can be used to correct a range of refractive errors, such as severe levels of short-sightedness and long-sightedness.

Unlike laser techniques that correct vision by changing the shape of the cornea, clear lens extraction corrects vision by removing the natural crystalline lens and replacing it with a new artificial implant (intraocular lens or IOL) of a different focusing power, much like what happens in cataract surgery. However, in cataract surgery the lens that is removed is cloudy whereas in this procedure it is clear.

It involves the insertion of either a single or multi-focal lens to improve defective vision. It is especially useful for patients with a severe level of myopia, hypermyopia or astigmatism. With clear lens extraction there is no need for glasses or ordinary contact lenses.

There are two types of lenses used in clear lens extraction: single vision or ‘monofocal’ lens; and accommodating or ‘multifocal’ lens. The single vision is as the name says: it is a fixed focus type of lens which can correct a single refractive error. So, if you are
short-sighted then you will find that you are able to see objects at a distance but, you will still require glasses/contact lenses for close up work. The multifocal lens will treat both types of error (short and long sight). This means that you will be able to see objects both near to and at a distance.

If you have a severe level of myopia, hyperopia or astigmatism then you are likely to be a suitable candidate for this procedure.

Clear lens extraction is most suitable for those over 50 years of age. This is because when the natural lens of the eye is removed all ability to adjust the focus of the eye is lost. This natural focus changing ability is called ‘accommodation’, and it is slowly lost with age. It is this loss of accommodation that accounts for near vision/reading glasses after the mid 40’s. When clear lens extraction is performed on those over 50 the loss of accommodation is irrelevant as it has already been lost through the natural ageing process.

Risks of clear lens extraction
All surgery carries some uncertainty and risk 
When eye surgery is performed by a qualified refractive surgeon, complications are infrequent and usually minor. Nevertheless, there is always a possibility of complications, including infection or a reaction to the anaesthesia.

This is a safe procedure but possible risks include:

•    Damage to the structure of the eye
•    Corneal decomposition
•    Retinal problems/complications
•    Cystoid macular oedema

If you have a very severe form of short-sightedness then you are at increased risk of retinal detachment.

Preparing for surgery
Before the lens extraction surgery, your surgeon may ask you to temporarily stop taking certain medications that increase the risk of bleeding during surgery. You will also need to have measurements taken from your eye so the right lens can be selected to implant.

Types of anaesthesia
For most patients, the surgery is done under local anaesthesia using drops instilled on the surface of the eye. This means you'll be awake during the surgery, but insensitive to any discomfort.

The surgery
After the eye is numbed and the pupil is dilated by using eye drops, a tiny incision is made in the eye. Through this incision, the surgeon inserts an instrument, about the size of a pen tip. This device emits ultrasound waves that soften and break up the natural lens so it can be removed by suction.

Once the natural lens has been removed, the artificial lens or an intraocular lens (IOL) is then inserted into the space previously occupied by the natural lens. There is usually no need for stitches and you will not feel or see the new lens.

Each eye takes about half an hour so you’ll spend just a few hours at the site.

After surgery
The small incision will heal quickly, and vision should improve within a couple days. Following surgery, you will be asked to use eye drops for a few weeks to guard against infection. You should also avoid rubbing or touching your eyes during the recovery period.

Getting back to normal
Many patients find that they are back at work and doing their normal everyday activities within two weeks of surgery.

The new look
If you had surgery to correct a severe refractive error you will be rewarded with clear vision and the ability to see objects close to and at a distance. So, no more reading glasses and contact lenses.