Posted on November 29, 2017
The Implantable Collamer Lenses, ICLs 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. The first, posterior chamber phakic lenses or ICLs are positioned between the iris and the natural lens of the eye, while the second are placed on the iris and are called anterior chamber phakic lenses.
The ICL is similar in function to a contact lens, since it is invisible to the naked eye, and allows perfect vision without glasses by correcting the refractive error. However, unlike a contact lens, it is a permanent solution for refractive errors and spectacle free life. In addition to that, it is free from the frequent side effects of wearing contact lenses: infections, allergies and dry eyes being the most common.
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 because of the material of the ICL. Since the ICL is inserted into the eye using a small, relatively painless incision, it can be used in patients with thin corneas, large pupils, as well as dry eye, and in refractive errors as high as -20D.
The most commonly used ICL is the posterior chamber ICL, called Visian ICL marketed by Staar Surgical (Monrovia, USA and Nidau, Switzerland) is made of soft, biocompatible collagen polymer and is extremely 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 upto -3 to -23 D of sphere and + 1.0 to + 6.0 D of cylinder as well. This means that Toric ICL corrects your nearsightedness as well as your astigmatism (cylindrical power) in one single surgical procedure, completely.
In case you have a high astigmatism, that is, correction of your refractive error requires not only a spherical number, but also a cylindrical prescription, your doctor will offer you a toric ICL in order to completely remove your need for glasses. Astigmatism means your cornea is of a different shape than usual, and a mere spherical correction then is not sufficient for perfect vision (for better understanding imagine an egg shaped cornea, when it should actually be shaped like an orange).
The toric ICL is similar in design and material as 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 best fit the specific needs of your eye. 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 time period maybe considerably reduced.
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 keratoconus, and corneal transplants (including penetrating keratoplasty and Deep Anterior Lamellar Keratoplasty, in cases with adequate anterior chamber depth), who aren’t excellent candidates for LASIK, as also patients with thin corneas and astigmatism due to other corneal ectasias. Sometimes, patients 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 completely spectacle free life.