RK is a procedure in which several deep cuts are made to flatten the cornea but RK has become obsolete with the introduction of lasers.
In PRK treatment, the top layer of the cornea is first removed, followed by the use of the laser beam to reshape the cornea surface. The top layer of the cornea regrows over several days. PRK is only suitable for low to moderate degrees of short-sightedness.
The Laser Epithelial Keratomileusis procedure combines the safety of the traditional PRK treatment with several of the advantages of LASIK. LASEK is actually a further development from PRK. In this procedure, the cornea’s epithelium is not removed, but reflected to the side using dilute alcohol solution and is put back in place after the laser treatment. LASEK has the relative advantage as it avoids any of the potential complications encountered while making the flap and during the flap healing process. However, the vision recovery period is slower and the patient will experience mild discomfort up to a few days after the procedure.
As with PRK, a thin soft bandage contact lens will be prescribed and good functional vision usually achieved within 7 days after treatment. LASEK is suitable for patients with thin corneas and sometimes for myopic, or hyperopic patients.
The Epithelial Laser In Situ Keratomileusis procedure is an advanced type of corneal surface ablation to correct myopia, hyperopia and astigmatism. The EPI-LASIK procedure, a specially designed microkeratome like instrument is used to create a thin flap of corneal epithelium. It achieves this by gently separating the epithelium from the underlying corneal layer without cutting. Unlike LASEK, no alcohol solution is needed to remove the surface of the epithelium.
Once the epithelial layer has been removed, the Excimer Laser is then applied to reshape the cornea to correct your prescription, as in LASIK, PRK and LASEK. After the laser has been applied, the epithelial flap is then returned to its original position.
Similar to PRK and LASEK, EPI-LASIK avoids of the potential complications encountered from a corneal flap creation. Comparatively, it is believed that EPI-LASIK allows more rapid visual recovery, perhaps 3-4 days versus 7 days or more with PRK and 5-7 days with LASEK.
A thin soft bandage contact lens will be worn for several days after treatment to help with healing and to minimize discomfort. This procedure is mostly suited for patients with thin corneas or has certain conditions of the cornea, such as scarring or trauma.
LASIK is a highly automated, computer-controlled procedure that takes just 3-5 minutes. It is virtually painless and offers rapid, next-day recovery.
The surgeon creates a thin flap through the top layer of the cornea. The flap is gently folded over and the surgeon performs the laser treatment on the layer underneath. This usually takes about 2 minutes per eye. The flap is then replaced and left to heal naturally without any stitches.
Zyoptix is a much more advanced method of LASIK using wavefront technology. Specifically, Zyoptix is different because its highly sophisticated technology allows the surgeon to:
- examine the entire eye for previously unseen details known as 'aberrations' (imperfections).
- plan the treatment that can correct individual visual errors and aberrations in the eye.
- programmed the laser with a combination of small and large beams to deliver a unique treatment for every individual eye.
Your cornea is naturally aspheric (or elliptical) in shape. It is Mother Nature's gift to allow us to have better contrast and clarity especially in dim light conditions.
In standard LASIK treatment, the shape of your cornea is flattened slightly to correct myopia. Some patients may encounter side effects such as poorer night vision and seeing glares, starbursts and haloes after Standard LASIK.
Zyoptix Aspheric can better preserve the aspheric shape your cornea, resulting in better visual performance for patients especially at night.
A recently global clinical trial showed that Zyoptix Aspheric reduces post-LASIK side effects by 76% compared to Standard LASIK surgery. Most patients who underwent Zyoptix Aspheric surgery could see better at night or under low light conditions compared to Pre-LASIK surgery aided vision (i.e. wearing glasses or contact lenses.) This is the first Aspheric LASIK treatment that has clinical proof behind claims in preserving the natural shape of your cornea and improving night vision.