Implantable Lenses – Visian & Verisyse Phakic Lenses – IOLs
Phakic IOLs, or implantable lenses, are refractive lenses that are inserted inside the eye to correct vision.
The word phakic (pronounced "FAY-kick") means the eye's natural lens, located behind the iris and pupil, remains intact. It is not removed in the phakic IOL procedure, as it would be in cataract surgery or refractive lens exchange (RLE).
"IOL" is an abbreviation for intraocular lens. The phakic IOL procedure, then, involves placing a small lens inside the eye, while the eye's natural lens remains intact.
When Phakic IOLs Are Used
Phakic IOLs generally are used to reduce or eliminate nearsightedness that is too severe to be corrected by LASIK surgery or to correct myopia in patients whose corneas are too thin for LASIK, PRK or other laser vision correction procedures (including LASEK and Epi-LASIK).
Types of Phakic IOLs
There are two basic types of phakic IOLs:
Anterior chamber phakic IOLs
An anterior chamber IOL is attached to the front of the iris. Therefore, it resides in the anterior chamber of the eye—the space between the back surface of the cornea and the front surface of the iris. An example of an anterior chamber phakic IOL is Advanced Medical Optics' Verisyse Phakic IOL.
Posterior chamber phakic IOLs
A posterior chamber phakic IOL is implanted in the small space between the back surface of the iris and the front surface of the eye's natural lens (also called the crystalline lens). An example of a posterior chamber phakic IOL is Staar Surgical's Visian ICL.
('ICL" is an abbreviation for Implantable Collamer Lens, which is so named because of the biocompatible and flexible "collamer" material the Visian phakic IOL is made of.)
Advantages of Phakic IOLs
Phakic IOLs have a number of advantages over LASIK, PRK and other corneal laser vision correction procedures.
Proponents of the procedure say the implantable lenses provide sharper vision than laser vision correction surgery. The manufacturing process for phakic IOLs reduces the risk for optical distortions and higher order aberrations that can be caused by laser procedures, especially when corrections for high amounts of myopia are needed.
Also, because no corneal tissue is removed during the phakic IOL procedure, there is no risk of dry eye problems caused by damage to delicate nerves in the cornea that are important in maintaining an adequate tear layer on the eye.
Another advantage of phakic IOLs is that, if complications arise, the implantable lenses can be removed or replaced if necessary. Unlike LASIK, PRK and other laser surgery, phakic IOL surgery is fully reversible.
Risks of Phakic IOLs
Because implantation of phakic IOLs is an internal eye procedure, the surgery has some risks that typically are not concerns associated with LASIK and other laser procedures that are confined to the front surface of the eye.
Also, routine and careful eye exams are needed throughout the patient's lifetime after phakic IOL surgery to make sure the lens implant does not damage surrounding tissues within the eye or cause other long-term complications.
Possible short-term and long-term complications of phakic IOL surgery include:
- Sudden rise in internal eye pressure (IOP) that could lead to glaucoma
- Loss of cells on the inner surface of the cornea (the endothelium) that could cause corneal edema and blurred vision
- Inflammation inside the eye
- Retinal detachment
- Cataracts
When considering phakic IOL surgery, be sure to discuss the rewards, risks and potential complications of the procedure with your refractive surgeon before consenting to surgery.
FDA-Approved Phakic IOLs
Currently, only two phakic IOLs are approved by the FDA for the correction of moderate and high myopia in the United States:
- Verisyse Phakic IOL (Advanced Medical Optics, Santa Ana, CA)
- Visian ICL (Staar Surgical Co., Monrovia, CA)
Costs for implantable lenses is typically higher than the average LASIK surgery cost.
Note: This information is for general education purposes only. It is not to be used as a substitute for medical advice from your eye doctor or refractive surgeon.
