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Introduction

Like LASIK, PRK is a laser refractive procedure that corrects the focusing power of the eye to reduce your dependence on glasses and contact lenses. If you have short-sightedness, long-sightedness or astigmatism, your vision is blurry without glasses or contact lenses because light does not come to a clear focus at the back of the eye.

PRK surgery permanently corrects for short-sightedness, long-sightedness and astigmatism by changing the curvature of the front surface of the eye so that light enters and focuses clearly at the back of the eye. In doing so, it removes the need for glasses and contact lenses to achieve clear vision.

PRK surgery does not involve the creation of a flap and that is the main difference that distinguishes it from LASIK. In PRK, the reshaping ablation is performed directly on the surface of the cornea, hence it is also called surface ablation.

Who is suitable for PRK surgery?

To be a suitable candidate for PRK surgery, you should be at least 18 years of age, have had a stable prescription for the last 12 months and have healthy eyes.

PRK is generally preferred over LASIK surgery if you have thinner corneas, dry eyes, or if you engage in high impact contact sports or are in certain vocations such as the police force or armed forces.

At your laser eye surgery consultation, a detailed assessment will be performed to ascertain your prescription as well as your corneal thickness, shape and general eye health. You will be advised if PRK is the preferred treatment for your eyes and lifestyle. If LASIK and PRK are not suitable for you, you may be recommended alternative treatment options such as ICL, refractive lens exchange or cataract surgery.

How is PRK surgery performed?

Conventional PRK surgery is a two-step procedure that involves removal of the surface cells covering the cornea (the epithelium) with alcohol and a blade or brush, followed by reshaping of the underlying cornea.

At City Eye Surgeons, PRK surgery is performed with the Schwind Amaris 1050RS which simultaneously removes the corneal epithelium and reshapes the cornea in a single step. This single-step “no touch” laser treatment is commonly known as trans-PRK surgery. Trans-PRK surgery does not require the use of any surgical instruments, thus allowing for a gentler, less invasive and more comfortable experience for you. The recovery time is also quicker than conventional PRK surgery.

At the end of the procedure, a soft contact lens is placed on the eye to allow re-growth of the corneal epithelium, which typically takes 3 to 5 days.

Single-step trans-PRK procedure

Introduction

LASIK is a laser refractive procedure that corrects the focusing power of the eye to reduce your dependence on glasses and contact lenses. If you have short-sightedness, long-sightedness or astigmatism, your vision is blurry without glasses or contact lenses because light does not come to a clear focus at the back of the eye. Glasses or contact lenses help by adjusting how light is bent as it enters the eye.

LASIK eye surgery permanently corrects for short-sightedness, long-sightedness and astigmatism by changing the curvature of the front surface of the eye so that light enters and focuses clearly at the back of the eye. In doing so, it removes the need for glasses and contact lenses to achieve clear vision.

LASIK is the most popular laser vision correction procedure performed today because it causes minimal discomfort and very little downtime, allowing you to return to your usual activities almost immediately.

Am I eligible for LASIK eye surgery?

To be a suitable candidate for LASIK eye surgery you should be at least 20 years of age, have had a stable prescription for the last 12 months and have healthy eyes. As a general rule, you will be eligible if your prescription is in the range of -10.0 to + 4.0 diopters provided corneal thickness is adequate.

At your laser eye surgery consultation, a detailed assessment will be performed to ascertain your prescription as well as your corneal thickness, shape and general eye health. If you are found to be ineligible for LASIK, you may be recommended a more suitable procedure such as PRK, ICL, refractive lens exchange or cataract surgery.

How is LASIK eye surgery performed?

LASIK surgery is a two-step procedure. In the first step, a femtosecond laser creates a thin flap of corneal tissue on the surface of the eye. The flap is then lifted and reflected to expose the deeper corneal tissue.

In the second step, a computer guided excimer laser removes corneal tissue from the exposed surface in a precise manner, reshaping your cornea to correct for your prescription. Finally, the flap is repositioned and allowed to adhere naturally.

You will be awake during the procedure as we need you to fixate on a light to keep your eyes steady. Your eyes will be numbed with drops for the surgery, so you won’t feel anything, and if needed, a light sedative tablet may be given to help you relax.

What is an implantable collamer lens?

An implantable collamer lens (ICL), also known as an implantable contact lens, is a vision correction lens implant that is implanted into the eye to correct short-sightedness (myopia), long-sightedness (hyperopia) and astigmatism. It functions exactly like a contact lens, except that it is surgically implanted into the eye. Unlike a contact lens, an ICL does not require any maintenance, and it cannot be seen or felt once implanted in the eye.

Am I a good candidate for an implantable collamer lens?

To be a suitable candidate, you should:

• Be between 21 and 45 years old
• Have a relatively stable prescription in the last year

Implantable collamer lenses (ICLs) are a good alternative for patients who are not suitable for LASIK or other refractive procedures. ICLs can correct a wide range of refractive errors and are therefore commonly recommended to patients with high prescriptions that cannot be safely treated with laser eye surgery.

ICLs can treat the following refractive errors:

• Mild to severe myopia or short-sightedness (-0.50 to -20.0D)
• Mild to severe hyperopia or long-sightedness (+0.50 to +10.0D)
• Astigmatism (0.50 to 6.0D)

What is an implantable collamer lens made of?

Implantable collamer lenses are made of a proprietary material that contains a small amount of collagen which occurs naturally in your body, thereby making it biocompatible with the eye. The lens also contains an ultraviolet light filter to provide natural UV protection.

What are the benefits of an implantable collamer lens?

• The procedure is reversible – while the ICL is intended to be permanently placed in your eye to correct your vision, one advantage of the lens is that it can be easily removed or replaced if necessary. For the majority of patients, the lens remains in the eye until it needs to be removed, usually at the time when a cataract develops, later in life.
• The lens can be implanted with a quick, painless and minimally invasive procedure.
• Vision recovery is very quick; you will be able to return to work after 1-2 days.
• It is a safe and effective treatment for patients excluded from laser vision correction due to high prescriptions; thin, or abnormally shaped corneas; or severe dry eyes.
• It treats a wide range of prescriptions.
• The lens offers UV protection.

What does the surgery involve?

ICL surgery takes 20-30 minutes per eye and is performed under local anaesthetic.  A small opening is made in the periphery of the cornea to allow the ICL to be introduced into the eye through an injector. Once inside the eye, the lens unfolds and is positioned behind the iris. The small opening is self-sealing and does not require any sutures.

Visual recovery is fast and most patients are able to see very well by the next day. Your vision will continue to improve as the eye heals and settles down over the first few weeks following ICL surgery.

What is a refractive lens exchange?

Refractive lens exchange (RLE), also known as a clear lens exchange, is a surgical procedure in which the natural lens of the eye is removed and replaced with an artificial lens implant to correct refractive errors and minimise the use of glasses and contact lenses.

The surgical procedure is very similar to cataract surgery. The difference is that in cataract surgery the lens that is removed is cloudy whereas in RLE, a clear lens is removed.

Refractive lens exchange is used for the correction of refractive errors including short-sightedness, long-sightedness, astigmatism and presbyopia (an age-related loss of the eye’s ability to focus on near objects). By replacing the natural lens of the eye with a new artificial lens, the refractive error is corrected by altering the focus of the eye, thus eliminating the need for glasses or contact lens.