U Education

UltraView LASIK™ is one of our signature vision correction treatments. At UELC, we use it to correct problems like farsightedness, nearsightedness, and even astigmatism. While it yields excellent results, not all patients qualify for this procedure.

When determining whether you are a candidate for a flap-based laser refractive surgery, we assess several factors, one of which is corneal thickness.

Why is Corneal Thickness so Important?

Your cornea is located on the top layer at the front of your eye. It consists of several layers, namely the epithelium, Bowman’s layer, stroma, Descemet’s membrane, and endothelium.

UltraView LASIK™ corrects your vision by creating a flap in the top layers so that the stroma can be accessed and reshaped by removing corneal tissue. This is why your cornea needs to be sufficiently thick. If it’s too thin, the reshaping won’t produce the desired results.

Your doctor will calculate how much material needs to be removed using a diopter, which is a unit of measurement for determining focusing strength of your lens. For every diopter that needs correction, an estimated 15 microns of corneal tissue needs to be removed.

If you have myopia (nearsightedness), this tissue is removed from the centre of your cornea to flatten it. With hyperopia (farsightedness), it is removed from the cornea’s periphery to make the surface steeper. For patients with astigmatism, the goal is to make the curve in your cornea more even, allowing light rays to focus directly onto the retina for clear vision.

The average corneal thickness is 520 microns but it can vary from person to person. Since the excimer laser is removing tissue, the eye care professional at UELC will determine how much tissue there is to treat to ensure the procedure is safe and successful.

What if Your Corneas Are Too Thin?

If your corneas are too thin, does it mean that you’re stuck with glasses and contact lenses for the rest of your life?

Not quite. Patients who don’t qualify for UltraView LASIK™ may be candidates for another procedure available at UELC: photorefractive keratectomy, more commonly called PRK.

With this procedure, there is no flap creation. Your doctor will remove the top layer of your cornea (the epithelium) before using the laser to gently and carefully reshape your cornea. This layer grows back within three to five days. During this time, you wear contact lenses to protect your eyes and follow your doctor’s instructions for daily activities like driving, reading, and going to work.

PRK is a great option for people with thin corneas. Although the recovery time is generally longer than with UltraView LASIK™, many of our patients say that the dramatic vision improvement makes it well worth the wait.

If you’ve always wanted perfect vision and no longer want to rely on glasses or contacts, the professional team at UELC will recommend the best procedure based upon (among other things) the thickness of your cornea. To schedule a complimentary consultation with a UELC surgeon, please call us at 416-653-8352 or contact us online.