Implantable collamer lens (ICL) insertion is a treatment for myopia, also known as nearsightedness, that involves creating an opening into the cornea through which a new lens is inserted. This process is more invasive than LASIK, and is more similar in method to cataract surgery involving intraocular lenses (IOLs), except that the implantable collamer lens stays in place, while it is removed in cataract treatments.
ICLs, also called phakic lenses, were initially developed after a World War II doctor observed that shards of shattered canopy that he removed from pilots’ eyes were inert—they did not react with the eye material. This inspired extensive testing of possible implantable corrective lenses, but these early trials had very high complication rates, and various attempts in the following decades failed to provide satisfactory results. Large incisions resulted in surgically-induced astigmatism, the lens itself caused cell death in the corneal endothelium (the single layer of cells on the surface of the cornea facing the iris), and various other problems ensued. As recently as the 1980s, publicly available products had to be removed from the market due to unacceptably high complication rates.
The process has since been improved greatly, and in 2005 the FDA approved a modernized ICL, requiring that the name implantable contact lens be changed to implantable collamer lens to avoid confusion. The modern procedure uses a rolled lens to allow the use of a smaller opening in the surface of the eye. Though less likely under current practices, endothelial cell loss is still possible. Cloudiness similar to natural cataracts can develop if the lens is handled improperly during surgery, and increased fluid pressure in the eye is a possible side effect.
ICL surgeries are only available for patients aged 21 to 45, as studies have not yet examined the safety or efficacy outside that age range for this relatively new procedure. The treatment is largely used for those who have very high levels of myopia or who have corneas that are too thin for LASIK.
ICL is not suitable for those with large pupils, as complications may occur if the pupil expands to a size larger than the lens, or for those with previous eye injuries or surgeries. Additionally, ICL is not recommended for people who are likely to receive trauma to the eye, as this procedure increases the likelihood of rupturing the eye.
Given the short period that the technology has been available, no studies have examined the long-term safety or efficacy of implantable collamer lens treatments. Even so, many patients report positive results. Each patient’s needs and eyes vary—talk to your eye doctor to determine the best solution for your eyes.