The eye is a complex organ and vision is a complex process. We know that while the human body is an amazing creation, not all body parts work as perfectly as we like them to. For millions, if not billions, of people around the globe, refractive error and the dependency on glasses or contact lenses for vision correction is just part of life. But if you’re a spectacle- or contact lens-wearer yourself, you know that these optical aids are not always the most convenient, particularly for a busy, active lifestyle. This then leads to the question – what is laser eye surgery and what can it do for you?
Before detailing exactly what is laser eye surgery, we must first understand the underlying problem. Refractive error refers to an optical state where the bending of light entering the front of the eye doesn’t focus properly onto the retina at the back of the eye; this may involve short- or long-farsightedness, and astigmatism.
The result of refractive error is blurred vision at certain distances. The vision correction offered by glasses and contacts works by bending light through the spectacle or contact lens in such a way that light ends up focusing perfectly onto your retina, resulting in sharp vision.
In the 1980s the first laser eye surgery was introduced in the form of photorefractive keratectomy.
What is Laser Eye Surgery?
Laser eye surgery is a form of vision correction utilizing laser technology. Whereas optical aids are worn externally to redirect the path of light through the eye to provide vision correction, laser surgery adjusts the shape of the anatomical components of the eye itself to change the way light enters the eye.
The main benefit of vision correction through laser eye surgery is that it can greatly reduce a patient’s dependence on glasses or contacts. For some fortunate people, laser eye surgery may eliminate their need for glasses or contacts entirely, depending on a number of factors such as initial refractive error, age, the laser surgery technique used, and lifestyle.
How Does Laser Eye Surgery Work?
There are two main refractive components of the human eye – the cornea, which is the clear dome of tissue at the very front of the eye, and the crystalline lens, which sits hidden just behind the colored iris. Refractive laser surgery treatments center around reshaping the cornea such that light passing through it is redirected to focus properly onto the retina and provide clear vision.
Two types of medical-grade laser technologies are used for refractive laser eye surgery – a femtosecond laser and an excimer laser, though not all of the laser surgery procedures require both. There are several types of laser eye surgery – and in addition to these techniques, there are further methods of refractive surgery that aim to achieve surgical vision correction but don’t involve lasers. Just to name a few of the most well-known procedures:
PRK: short for photorefractive keratectomy, PRK treatment involves mechanical or chemical removal of the superficial layers of the cornea known as the epithelium. Beneath the epithelium and its underlying membrane is the corneal stroma. The excimer laser is used to reshape the stromal tissue in a process called photoablation, entirely controlled by a computer algorithm.
LASIK: potentially one of the most popular laser eye surgery techniques, laser-assisted in situ keratomileusis also applies an excimer laser to the corneal stroma in photoablation, but the difference from PRK lies in the removal of the epithelial layers. Instead of total removal, a flap of superficial corneal tissue is created, which is comprised of the epithelial layers plus a small degree of the stroma. This flap remains attached to the main cornea and is repositioned after the photoablation step. The formation of the flap may be via a manual bladed instrument or, more recently, more precisely through the use of the femtosecond laser.
SMILE®: small incision lenticule extraction is one of the most modern methods of laser eye surgery, with significant benefits from its minimally invasive nature. Using a femtosecond laser, a pre-calculated disc-shaped sliver of tissue known as a lenticule, is created within the corneal stroma without needing to disrupt the epithelium. The extraction of this lenticule via a keyhole incision reshapes the cornea from within, thereby correcting for refractive error. Though the treatable prescription ranges vary between procedures, many of these are suitable for farsightedness, nearsightedness, and even astigmatism.
Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.
If you’re interested in the freedom that laser eye surgery can offer you and your active lifestyle, book your initial appointment with us now by calling us on 1300 297 583 or booking online.