The Implantable Collamer Lenses are very thin lenses that are placed inside the eye so that your vision can improve without the use of spectacles. There are two types of ICLs:
- Posterior Chamber Phakic Lenses are positioned between the iris and the natural lens of the eye
- Anterior Chamber Phakic Lenses are placed on the iris
The most commonly used ICL is the posterior chamber ICL, called EVO Visian ICL marketed by Staar Surgical (Monrovia, USA and Nidau, Switzerland) is made of soft, biocompatible collagen-polymer and is exceptionally flexible. The spherical ICL is used for the correction of moderate to high myopia ranging from –3.0 D to –20.0 D. The Toric ICL, on the other hand, can correct up to -3 to -23 D of sphere and 1.0 to 6.0 D of cylinder as well. It means that Toric ICL corrects your nearsightedness as well as your astigmatism (cylindrical power) in one single surgical procedure, completely.
In case you have high astigmatism, that is, correction of your refractive error requires not only a spherical number but also a cylindrical prescription, your ICL specialist will offer you a Toric ICL to completely remove your need for glasses. Astigmatism means your cornea is of a different shape than the usual, and a mere spherical correction then is not sufficient for perfect vision (for better understanding imagine an egg-shaped cornea when it should be shaped like an orange).
The Toric ICL is similar in design and material to the Spherical ICL, with the addition of a toric optic for the correction of the cylindrical error. The toricity is manufactured in the plus cylinder axis, within 22 degrees, which allows your doctor to get the ICL tailor-made to fit the specific needs of your eye best. Since the ICL is manufactured in a single unit for perfect quality control, there may be a time lag between taking measurements from your eye, and subsequently performing the surgery, as the toric ICL may be specially manufactured to meet your specific needs. Your doctor will key in your details into an online calculator, and if your eye specifications are available in the maintained inventory, this period may be considerably reduced.
Where can Toric ICLs be used?
The Toric ICL over time has proven to be an extremely safe and effective option for better vision without glasses even for patients following surgery for:
- Corneal Transplants (including Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty, in cases with adequate anterior chamber depth),
- Who aren’t excellent candidates for LASIK,
- Patients with thin corneas
- Astigmatism, due to other corneal ectasias.
- Sometimes, patients’ eyes are not fully corrected following refractive surgeries like LASIK, SMILE, etc, and after intraocular lens transplant following cataract removal. Toric ICLs can also be used for these patients with residual refractive error to allow them a complete spectacle free life.