Lens Implants | Lens Replacement

Lens Implants where the Natural Lens of
the Eye is Retained

Phakic (ICL) Lens Implants

These procedures can be classified into three main types. In two of these procedure types the implantable contact lens (ICL) is placed in front of the iris, whilst in the other procedure the ICL is placed behind the iris.

A Phakic ICL is an Intra-Ocular Contact Lens that is placed inside the eye in someone who still has their natural lens (i.e. they are “phakic”). For severely short-sighted people LASIK may not be suitable. These are the people most suited to Phakic ICL’s. Another key difference between LASIK and Phakic ICL’s is that laser surgery is permanent and cannot be reversed, whereas it is possible to remove or to replace a Phakic ICL.

Phakic ICL Lens implants are options for younger and middle aged patients with severe myopia because the lenses of their eyes are still elastic and have not yet lost their ability to accommodate (they are able to see at close distances without the need for reading glasses). With the aid of ICL’s these patients are given the opportunity to reduce their dependency on spectacles or contact lenses while conserving the ability of their natural lenses to accommodate for close-up vision.

Phakic ICL’s have real advantages for higher levels of myopia (say from 8 dioptres to 20 dioptres). The refraction is achieved with a manufactured lens implant which is made to an exact predetermined refractive power. Thus the result does not depend on the less predictable interaction between the cornea’s biological tissue and a laser beam. A phakic ICL has the advantage that it is removable if the patient is not happy with the result. It is usually possible to exchange the implanted lens for one of a different power if need be. Phakic ICL’s may be better in patients who have dry eyes as this can be made worse by LASIK.

Phakic ICL’s are typically used when surgical procedures to the cornea, such as Lasik, cannot be performed or are at their limit. This is very often the case when the cornea is too thin.

The advantage associated with the use of Phakic ICL’s is the ability to correct myopic and hyperopic refractive errors. Some of these advantages can be highlighted as follows:

Excellent refractive accuracy.
Preservation of accommodation.
Compatibility with cataract and clear lens replacement surgery very often referred to as ‘Refractive Lens Replacement Surgery (RLR)’
Correction of higher levels of myopic and hyperopic refractive errors.

Phakic ICL’s work like a contact lens, but instead of being placed on the surface of the eye, it is surgically placed inside the eye into the anterior eye chamber and it is secured into place on the iris or between the posterior surface of the cornea and iris with two small flexible hooks. Severe short sightedness and long-sightedness can further be corrected through the implant of an additional synthetic lens (RLR) into the eye, which thereby contributes towards better correction of the existing refractive error.

The disadvantage of the phakic ICL is that surgery is intra-ocular (like a cataract operation). A remote chance that surgery may introduce an infection into the eye does exist. Other surgery related complications are possible. In some patients problems with night vision and glare have been reported. Less glare and haloes are experienced when compared to the glare often associated with LASIK.

Bifocal Phakic Lens Implants

Bifocal phakic lens implants are available. These lenses are inevitably a compromise between near and distance vision. This may be a reasonable option for someone who is very keen to be rid of spectacles and who can accept a slightly reduced quality of near and distance vision.

The ARTISAN Lens

The most widely-used phakic ICL in Europe is the Artisan (Ophtec) iris-fixated ICL. In 2001, more than 60% of all phakic ICL’s implanted in Europe were the Artisan lens. This lens is sometimes referred to as the ‘iris-claw’ lens as it is placed in the anterior chamber of the eye and clips onto the iris so that it remains central in the eye and cannot move. It is used to correct hyperopia, astigmatism as well as extremely high degrees of myopia (up to -23.5 dioptres). The ARTISAN lens, manufactured in Holland, was first implanted in 1986. These lenses are placed permanently into the eye with the aim to reduce or eliminate the use of glasses or contact lenses.

Posterior Chamber Phakic ICL’s

Posterior chamber Phakic ICL’s are placed just in front of the natural lens, behind the iris. The Staar lens, which is manufactured in the United States, is the most well known posterior chamber phakic ICL.

Implantable Contact Lens Procedure which applies to Foldable Contact Lenses

Drops are placed in the eye to dilate and numb the eye.

After a tiny incision is made in the cornea the surgeon begins to insert the Implantable Contact Lens with a special lens insertion instrument. The unfolded lens, carried within the lens inserter, is deposited in the ideal location.

The unfolded lens (not visible to the naked eye) rests in front of the eye’s natural lens.

Most procedures take just 10 minutes to perform. After several hours the eye drops that dilated the eye, wear off and the pupil returns to it normal size.

Lens Implants Where The Natural Lens Of The Eye Is Removed And Replaced With An Artificial Lens

Clear Lens Replacement Surgery also referred to as Refractive Lens Replacement Surgery (RLR)

For RLR surgery the eye’s natural lens is first removed with the aid of ultrasound, and then it is replaced with a synthetic lens. The highly myopic patient's choices for surgical refractive correction are - implantation of a phakic ICL, as discussed earlier, or the replacement of the patient’s natural lens with a synthetic lens.