When we think of corrective surgery, we tend to focus on laser vision correction. LASIK is indeed the most common type of refractive surgery performed today, but it is not for everyone. If you have been told that you are not a good candidate for corneal laser surgery, then you may have a saviour in the form of phakic lenses, a lesser-known but equally effective alternative.
What are Phakic Intraocular Lenses (pIOLs)?
They are clear implantable lenses similar to those used in cataract surgery that function like contact lenses. However, instead of placing them on the surface of the eye, they are surgically placed inside the eye without removing the natural lens. They are soft and pliable and cannot be seen or felt after implantation. There are 2 types of implantable contact lenses (ICLs) and they are used to correct myopia (short-sightedness), hyperopia/hypermetropia (far-sightedness) and astigmatism:
Visian Implantable Collamer Lenses (ICLs) are the most widely used. They are positioned between the iris and in front of your natural lens and are inserted while folded, so a small incision of only 3.2 mm is required.
Artisan IOLs are attached to the iris using 2 tiny clips.
Who are pIOLs suitable for?
Younger patients between the ages of 21 and 45 with refractive stability (eyesight has not deteriorated significantly in the previous 2 years). Also, those who have problems with corneal thinness or scarring, dry eye syndrome, or a very high prescription (myopia greater than -11.00 dioptres (D), hyperopia greater than +5.00D and astigmatism greater than ±5.00D), which precludes them from undergoing laser vision correction.
What are the benefits?
They can correct very high prescriptions:
Myopia: Up to -17.00D
Hyperopia: Up to +12.00D
Astigmatism: Greater than ±5.00D
Vision after surgery is comparable to vision with contact lenses or glasses before surgery, so it dispenses with the need for either in the majority of cases. pIOLs have a very good long-term safety record, but if a problem arises, they can be removed quickly and easily (although this does not guarantee a return to previous visual acuity). Many eye conditions that develop as you get older, such as glaucoma, can be treated without necessitating removal of the implant. Cataract surgery may be performed as well, in which both the phakic and natural lens are removed in the same procedure.
What are the risks?
Any eye surgery incurs risks, but the chances of serious or permanent loss of vision are extremely low, as is the risk of infection. They may cause cataracts to occur earlier than normal and corneal clouding, which can result in loss of vision if not spotted quickly enough. Visual disturbances such as glare, ghost images, starbursts and halos are quite common when correcting a high prescription and may persist for several months. This can sometimes be quite incapacitating and make driving at night especially difficult.
Sometimes the size prediction for the Visian ICL is a little off, so the lens needs to be replaced with a different size to get an optimal fit. Minor rotation of the lens is also sometimes needed when correcting astigmatism. Although Artisan pIOLs are one size fits all, they also sometimes require a little repositioning.
pIOLs are more expensive than laser vision correction simply because they are custom made to your specific vision issues.
What does surgery involve?
Before the procedure you will be asked to refrain from using contact lenses and the surgeon will perform a laser iridotomy to prevent pressure build-up in the eye. A local anaesthetic will be administered along with a mild sedative, if needed. Drops are then used to dilate the pupils and a small, self-sealing incision is then made in the front of the eye through which the pIOL is injected. The eye is then washed out and refilled with fluid and antibiotics. The procedure takes around 20 minutes and causes minimal discomfort. You will be allowed to go home on the same day, although you will not be able to drive yourself. You may be able to get both eyes done at the same time, but many clinics advise doing one eye at a time to see if the sizing and position is correct. Vision may be blurry for the first few days and photosensitivity may occur. There may also be some eye discomfort, which can be alleviated with artificial tears. Any redness of the whites of the eyes is normal and shouldn't last more than 6 weeks.
If you wear high prescription contact lenses or glasses and thought surgical correction was out of reach, please contact one of our experts to see if phakic intraocular lenses can help you. Unlike the UK and USA, here in the Czech Republic they are approved for use in treating hyperopia as well, so all prescriptions will be considered.
Contributing writer: Natasha Robinson