Photorefractive keratectomy (PRK) has been introduced into ophthalmology in 1988. It is the “oldest” of the methods used in refractive laser surgery. The postoperative results, however, are absolutely comparable to newer methods like LASIK.
PRK, in contrast to LASIK, has a lesser impact on corneal biomechanics. PRK is preferred over LASIK in cases where corneal biomechanics may be compromised.
The newest variant of PRK is trans-PRK, where the corneal epithelium is removed not mechanically, but also with the means of a laser. This makes trans-PRK a true “non-contact” refractive laser procedure.
Z-LASIK (Femto-LASIK with the Ziemer Femtosecond Laser)
Z-LASIK represents the most modern version in LASIK surgery. It enables the surgeon to precisely position the flap on the corneal surface, and change the position by micrometers, if necessary
Before the procedure
After the pre-examination, you may wear your contact lenses until the day before the surgery.
The surgery itself takes a few minutes only, and the laser ablation a few seconds only.
PRK: We operate in two sessions, leaving one week in between the surgeries. This is due to the slower healing in PRK.
Only an eye care professional can determine whether or not an individual is eligible for LASIK treatment. In general, a good LASIK candidate is at least 18 years old, has healthy corneas, and has maintained a stable eye prescription for the last 12 months. Because hormonal levels can affect the shape of the eye, women who are pregnant or nursing should not undergo LASIK treatment. The procedure should also not be performed on patients who:
- Have glaucoma, cataracts or dry eyes
- With collagen vascular, autoimmune or immunodeficiency diseases
- Show signs of keratoconus (an eye disorder in which there is thinning of the cornea that results in blurred or distorted images)
- Take medications with ocular side effects (such as Accutane® or Cordarone®).
- Halos – Some patients will notice glare, halos or starburst around objects in low-light conditions. For the vast majority, these symptoms are temporary. However, others will continue to experience them for several months or longer. During pre-operative evaluation, the refractive surgeon can determine whether or not a person is at high risk for seeing long-term halos.
- Dry eyes – There is increased dryness of the eyes typically for several months following LASIK, though some patients may experience dryness for a longer period of time. It is important to use lubricating drops frequently. If the eyes remain dry for prolonged period, there are other drops or techniques that can help. Pre-operative evaluation will help determine whether or not a person is a likely candidate for experiencing dry eyes.
- Infection – This is an extremely rare occurrence, with a 1 in 2000-3000 chance (similar to any eye surgery). Fortunately, as the LASIK technique has developed over the years and proven to be of great benefit to millions of patients nationwide, firmly established protocols now exist which minimize the risk of infection.
Because contact lenses change the shape of the cornea, LASIK candidates are required to switch to eyeglasses before their baseline evaluation is taken and continue wearing only eyeglasses between 2-4 weeks before LASIK surgery. Not leaving contact lenses out long enough for the cornea to assume its natural shape before surgery can cause inaccurate measurements and poor vision after surgery
PRK: The procedure is painless, however, most people experience pain during the first 48 hours after the procedure, during the healing of the corneal epithelium.
LASIK: In most cases, people can return to work within 1-3 days following LASIK surgery. Excluding the day of surgery itself, people may begin driving as soon as they see well enough. Women can start wearing makeup within two to three days of treatment, however, they are advised to wear only new cosmetics in order to decrease risk of infection.
PRK: Vision is blurred, and the cornea can be painful during the first three days following the surgery. You should refrain from driving during the first week after surgery.Women can start wearing makeup at one week after the surgery, however, they are advised to wear only new cosmetics in order to decrease risk of infection.