PRK

LASEK

A slight variation on the traditional LASIK procedure is becoming available, LASEK. This procedure may be an option for patients who are not good candidates for the traditional procedure.

LASEK is a relatively new surgery that utilizes a trephine to create an epithelial flap (as opposed to a deeper stromal flap with LASIK) and an alcohol solution to preserve the epithelial cells. Once the epithelial flap is created and lifted, the treatment proceeds as for traditional PRK, with light smoothing at its conclusion. Then, the epithelial flap is repositioned with a small spatula.

LASEK preserves more corneal tissue, on average, than a typical LASIK procedure. Therefore, for patients who have thin corneas, LASEK may offer a safer alternative than LASIK.

Several small peer-reviewed studies have recently been published about the LASEK procedure.^1-5 All have concluded that this technique has the potential for use within the clinical practice, noting patients achieved results similar to those achieved with LASIK or PRK. All also noted that additional long-term studies were needed to confirm these early results. As more ophthalmologists are trained in the procedure and offer this technique as an alternative to patients, we expect to see more studies collaborating these initial results.

The FDA approves drugs and devices, not specific surgeries. However, the FDA evaluates the safety and efficacy of a device within the context of studies that have been done on a particular procedure, like PRK or LASIK.
On those lasers that have earned approval based on PRK or LASIK data, LASEK is permitted as a practice of medicine. The use of devices during a procedure deemed a practice-of-medicine is called an "off label" use of these devices. Because the approved lasers and trephines have proven safe and effective in other procedures, ophthalmologists may use them off-label if they feel it is in their patients' best interest to do so.

We have provided Tough Questions for Doctors on our website for some time. We have listed below a few more that will be of assistance if you are considering LASEK.

• What training have you received on this particular surgical procedure?
  
• What should my expectations be for healing at one day? one week? one month? etc.
  
• Are there any quality of vision issues I need to understand? (risk of glare/halos, decreased contrast sensitivity, etc)
  
• What complications are associated with this procedure? How are they different from those of LASIK or PRK?
  
• What about my eyes makes me a good candidate for LASEK?
  
• What is the advantage of this procedure over LASIK for me?
  

As always, there are no right or wrong answers to these questions; however the answers should be of assistance in your evaluation.
The US FDA LASIK web site provides a checklist for prospective refractive surgery patients. You should carefully review those questions. We suggest you review that list and ask yourself the following:

• Are the risks associated with the surgery worth the potential benefit derived from the surgery?
  
• Am I generally a risk taker?
  
• Do I generally adopt new technology early on, before others, or do I wait until it is more mainstream?
  

In sum, LASEK may offer patients with thin corneas a viable option to preserve more corneal tissue. However, the LASEK procedure is relatively new and is an off-label use of the excimer laser. Patients should be sure to discuss this option fully with their ophthalmologist.

Laser Thermal Keratoplasty (LTK)

LTK has been approved by the US FDA for temporary reduction of moderate hyperopia (+0.75D to +2.50D) with or without mild astigmatism (up to 0.75D). Patients must be 40 years or older. The procedure produces a change in the refractive power and properties of the cornea by using the heat produced by holmium laser light to modify the structure of the cornea's collagen fibers.
LTK involves the strategic placement of 16 laser spots onto the peripheral cornea. First the eye is numbed with anesthetic drops and held open with an eyelid holder so that the tear film can dry for 3 minutes before the laser is applied. The laser application itself takes less than 3 seconds per eye. The treatment thermally contracts the tissue, causing the central cornea to steepen. A bandage soft contact lens is usually placed on the eye until the following day. They eye may have some irritation for the first few days.
It is important for patients to note that the effects of this technique are temporary and the amount of correction will diminish over time. Patients who are interested in this option should discuss their expectations for length of time correction is viable with their ophthalmologists.