What is Lens Exchange?

Purpose

The aim of this procedure is to alter the refraction (or focus) of the eye by removing the natural lens of the eye and replacing it with a plastic artificial lens. This plastic lens is called a "lens implant". The natural lens is being exchanged for an artificial lens.

Intra-ocular surgery

Because the natural lens of the eye is located within the eye the procedure does involve intra-ocular surgery.

In other words it is an operation that involves entering the eye with surgery performed within the eye. In this sense it is different to laser refractive surgery (LASIK, epi-LASIK, LASEK or PRK). These involve surgery to reshape the cornea that is done on the outside of the eye. Lens Exchange is very similar to a cataract operation.

Who may benefit

This procedure can be used to correct both short sight (myopia) and long sight (hyperopia) that is too large to be safely and/or effectively corrected using laser surgery.

It is best suited to those patients aged over 50 years. 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-ability of the eye is called "accommodation". It is slowly lost with ageing. This is why, for those who have good distance vision, near spectacles are usually required after mid 40's. When "Lens Exchange" is performed on those patients aged over 50 the loss of accommodation is of little consequence as it has already been lost through the ageing process anyway. The procedure may still be performed on younger persons but near vision spectacles will be a new requirement for such patients.

Unlike the natural lens of the eye in a young patient the standard lens implant has a fixed focus, i.e. these types of lens implants do not have focus adjustment. Lens implants with focus-ability have recently come onto the market, but their long term effectiveness is still uncertain.

In some cases in order to achieve the best or desired focus for the eye it is necessary to combine Lens Exchange with other techniques. For example in eyes with large refractive errors (e.g. high myopia) Lens Exchange may be used to correct the bulk of the error and some laser treatment (e.g. LASEK) may be used to correct or refine any residual defocus. This approach is called Bioptics.

For more information please read the How does Lens Exchange work? section.