Phakic IOLs – treatment for short sightedness
Phakic IOLs (intra-ocular lenses) are clear implantable lenses that are surgically placed either between the cornea (clear window at the front of the eye) and the iris (the coloured portion of your eye) or just behind the iris, without removing your natural lens.
This lens does the same job as spectacles or contact lenses do in focusing the light but it lies within the eye and does its work from there. It is designed to take away the need for spectacle wear. It is placed permanently but can be removed surgically at any time.
A phakic IOLs offer a permanent correction of short sightedness/myopia.
Unlike contact lenses, you can't feel a phakic intraocular lens in your eye and, apart from regular eye exams to monitor the position of the lens, the health of the undersurface of the cornea and to check the eye pressure, phakic IOLs typically do not require any maintenance.
I use two types of Phakic IOLs. One sits in front of the iris and the other behind the iris adjacent to the native lens in your eye.
The Visian ICL (Implantable Collamer Lens) is a posterior chamber phakic IOL, meaning it is positioned behind the iris and in front of your natural lens. It is used for correcting nearsightedness ranging from -3.00 to -20.00 D.
Because the Visian ICL is placed behind the iris, it is undetectable to the naked eye and can only be seen through a microscope.
The Visian ICL is made of a soft, biocompatible collagen copolymer. Due to its flexibilty, the lens is able to be folded during implantation, allowing for a much smaller surgical incision.
AcrySof Cachet angle-supported phakic IOL:
The Cachet is a soft acrylic lens positioned in front of the iris and secured in the angle of the anterior chamber of the eye where the cornea and iris meet.
It can be used to correct short sightedness of -6.0 to -16.5 D.
Phakic IOLs versus LASIK Eye Surgery
Another frequently used option is to us LASIK laser treatment to correct short-sightedness.
It uses a computer-controlled laser to reshape the cornea.
There are some people who are better candidates for laser than a phakic IOL.
Contraindications to LASIK surgery include: a very high degree of nearsightedness (usually more than -8.00 D); having a cornea that is too thin or irregular in shape and eye conditions such as keratoconus and chronic dry eyes.
A 2010 study compared LASIK versus phakic IOL surgery for the correction of -6.00 to -20.00 D of short-sightedness (myopia) and found that the two procedures produced essentially equal odds of attaining 6/6 (20/20) perfect vision without corrective lenses one year after surgery.
The study also found that patients who underwent phakic IOL implantation had better contrast sensitivity and were more satisfied with their outcome than LASIK patients. Neither technique caused significant complications that permanently affected vision.
Risks and Complications
- As with any type of surgical procedure, phakic IOL surgery has certain risks. Fortunately, these risks are low. Possible short-term and long-term complications of phakic IOL surgery include:
- Retinal detachment, a serious and sight-threatening emergency situation.
- Glaucoma, increased eye pressure that can damage the eye's optic nerve and cause permanent vision loss.
- Loss of cells mining the inner surface of the cornea (endothelium) that could cause corneal swelling and progressive clouding of vision (I will have to do special tests at regular intervals to monitor the health of these cells).
- This is an intraocular procedure and involved going into the eye so there is a very small risk of infection in the eye.
- Distorted vision such as halos or glare, especially while driving at night, and blurry vision can occur.
- As the synthetic lens is placed close to your native lens sometimes a cataract can form a few years earlier than it otherwise would. This can be corrected surgically if needed.