Setting yourself up for success in refractive surgery Part II

November 1, 2009

In the second of a two-part article Dr David Tanzer says that in today's US Navy the preferred refractive procedure today is wavefront-guided LASIK with a thin flap made with a femtosecond laser.

Key Points

Whether we decide to perform PRK or LASIK, we choose custom treatments to the maximum extent possible. Through numerous clinical trials, we have proven that wavefront-guided correction provides significant benefits in clinical results and quality of vision for both LASIK and PRK.

In this article, I will describe our technique for LASIK and PRK in detail. More important than following exactly this technique, however, is to maintain a high level of consistency in your own techniques. Consistent flap lifting, repositioning, and stromal hydration is absolutely critical to obtaining the best results.

LASIK

Before surgery, we offer patients an oral anxiolytic such as Valium, Ambien or Xanax. Do not over-sedate, however, as you want the patient to be able to fixate on the laser.

I wait to apply the topical anesthetic until just before marking the eye. Limiting exposure to the anesthetic reduces the chance of epithelial sloughing.

Flap creation

To perform the IntraLase procedure, the suction ring is placed on the eye, decentered slightly nasally and superiorly. If there is any difficulty with visibility of the superior limbus, I elevate the patient's chin as needed to gain exposure.

The applanating cone on the laser is then docked to the suction ring. I prefer to minimize the meniscus, or non-applanated area in the periphery, and have a very low rate of suction breaks with this approach. You can gently lift and rock the ring slightly in the direction of the meniscus to reduce it.

We almost always perform the procedure with the pocket enabled. The pocket provides space for gas to vent so that it doesn't create the opaque bubble layer (OBL) that can otherwise obscure tracking and iris registration. If the flap is smaller than intended, you may want to consider going "pocket off" to increase the flap diameter by about 0.5 mm.

I use a Seibel flap lifter, which is a two sided-instrument with a short, slightly beveled metal dissector on one end, to lift the flap. With the dissector end, I score down through the epithelium and open the flap edge 1-2 mm at about 10 o'clock, just circumferential to the 12 o'clock hinge.

Then I insert the other end of the Seibel flap lifter, which is curved like a paint-roller or coat hanger, into the flap interface parallel to the hinge and open up half the flap at a time. This reduces tension on the hinge and the chance of tearing it. I retract the flap in a taco fold. With the stromal side touching stroma rather than in contact with the tear film, the chance of DLK is greatly reduced.