Posted on November 29, 2017
The Spherical ICL or Implantable Collamer Lens is usually prescribed for young people (age less than 40 years) who have very high power of glasses, and where the same cannot be corrected by the usual Lasik procedures due to either very high refractive error or thin corneas. The spherical ICL may be used for the correction of moderate to high myopia ranging from –3.0 D to –20.0 D. However, they are most commonly used in powers beyond -8 DS in eyes with normal corneas, or in eyes with lower power very thin corneas.
ICLs are ultra thin lenses that are placed inside the eye permanently to provide perfect vision without the use of spectacles. There are two types of spherical ICLs: one that is positioned between the iris and the natural lens of the eye and called the posterior chamber phakic lens or ICL, while the other is placed on the iris and is known as anterior chamber phakic lenses.
The most commonly used ICL is the posterior chamber ICL, called Visian ICL marketed by Staar Surgical (Monrovia, USA and Nidau, Switzerland).
The spherical ICL offers perfect vision correction to patients who do not require cylindrical correction for their astigmatism, that is, their refractive error is purely spherical. The vision results of ICL are sharper and the patients have a superior quality of vision than after other refractive surgeries. The visual recovery is almost immediate and the lens is invisible to both the patient and observers. The ICL is free from the frequent problems associated with contact lenses like infections, allergies and dry eyes, and are therefore the ideal surgical procedure for patients with preexisting ocular surface diseases where the conventional refractive surgeries like LASIK are known to aggravate the preexisting condition.
Since the lens is made of a biocompatible, flexible collamer, which contains a Ultra Violet light protector, the ICL completely prevents harmful UVA and UVB rays from entering the eye.
The ICL is inserted into the eye using a small, almost painless incision, and the surgery usually takes about fifteen minutes. Spherical ICL can be used in patients with thin corneas, large pupils, as well as dry eye, and in refractive errors as high as -20D, all of which are not suitable candidates for LASIK.
Like other refractive surgeries it is a permanent solution for refractive errors and spectacle free life. In addition to that, the most remarkable part of the procedure is that it is completely reversible, unlike LASIK. This means that the surgeon can un-do the procedure in the future in case of newer, better technology being available in the distant future also, or in case the patient wants to revert to his or her original refractive status for any reason.
Of all the currently available refractive surgeries, the quality of vision after ICL surgery is the best, with high definition vision and complete UV protection. Spherical ICLs have actually revolutionised the outcomes of refractive surgeries in the subset of patients who need it the most, but till now, have had no options but to continue with glasses.
For patients with astigmatism, though, either post surgical or pre-existing the Toric ICL provides a better visual outcome.