LASIK alternative: Advanced Surface Ablation

Patients need to have their individual needs evaluated from both a safety and effectiveness standpoint when considered for laser vision correction surgery.  The first laser treatment, and the one that the laser companies thought was going to be the only laser treatment was to treat the front of the eye with the laser and let a new skin or epithelium heal with the eye patched.  Although this was the most simple approach, it had several limitations.  For one, there was considerable discomfort, and this made it none to popular.  There were other problems such as haze or scarring of the cornea, decreased vision, and others.  When LASIK came along, as an upgrade to a previous procedure, ALK, it seemed to resolve most of these problems and was quickly adopted as the treatment of choice by most doctors.  We were fairly confident that the late changes of an older procedure, radial keratotomy, were behind us.

Radial keratotomy, popular in the 1980's and early 90's was based on a simple concept.  If you make some deep cuts into the corneal surface, it will heal quickly, and the cornea will take a new shape which when done correctly can improve vision dramatically.   This was the first "commercial" success of refractive surgery.  Other procedures like MKM had been done on a limited basis, but radial keratotomy (named after the radial shape to the incisions) became widely adopted with a large number of cases being performed.  Years later, a percentage of these patients experienced progressive effects from their surgery, and ultimately became farsighted.  It was realized that the cornea was weakened to a point that over time became unstable and the effect was progressive.  It is thought that in LASIK, that the cornea is not so deeply invaded, and therefore we will not have the same problems as radial keratotomy.

Except in cases of ectasia.  This is a condition where the cornea in some people is already somewhat weak and the added stress of LASIK can push it over the edge to an instable state known as ectasia.  We try as eye surgeons to avoid eyes that will develop this condition and in most cases we can screen these eyes out so as to avoid corneal refractive surgery.  The problem is that there is no absolute test nor finite point that indicates where this will be a problem.  Thin corneas, and irregularly shaped corneas give us warning signs, but sometimes even subtle changes can result in problems after LASIK. 

One huge help in recent years has been the all laser lasik method.  Besides the visceral reaction that we have to a blade vs a laser treatment there are some real safety benefits.  The blade, despite numerous attempts to make it more accurate as to the depth of the cut (I was involved in several clinical studies on this subject), there is no reliable way to mechanically cut a flap with extremely consistent depth, or invaseiveness into the cornea.  The femtosecond lasers have improved this considerably, and the newest of these, the VisuMax laser by Zeiss, is accurate to within a few microns.  This means that we can cut very thin and very accurate flaps that are only minimally more invasive than surface treatments, thus making this new improved LASIK available to more people.

However, in some cases, there is the need to do a surface treatment, due to very thin corneas, or suspicious scans or measurements.  There is also this need in corneas with scars, abnormalities to the surface, or other findings that suggest this is a better approach.  Fortunately, the PRK type of surface procedure has qualitatively improved, and has been renamed by some to advanced surface ablation.

In ASA we remove only a small circle of the epithelium, just big enough to do the treatment rather than a larger area.  We use the current state of the art excimer lasers, that much more smoothly polish the surface, not leaving ridges or sharp edges like some of the older lasers did.  And we use pharma agents, like mitomycin C to control healing, bandage contact lenses, and cool liquids to improve the eye tolerating this procedure.  Post operatively we have newer drops that control inflammation and pain, and thus can get results with excellent clinical outcomes while minimizing patient discomfort. There have also been breakthroughs in the oral medications that patients can be given for the first few days after their procedure to control any discomfort.  Although some patients do have significant discomfort for a few days, most report excellent vision and minimal pain with improved patient management.  Newer generation bandage contact lenses speed healing by wearing these for the first five days after the procedure.

The healing of ASA  is still much slower than that of LASIK, but we have a tool that can be useful to many patients.  Depending on the practice, doctors are moving back towards a surface treatment in more patients and anywhere from a small percentage, to almost half of the patients treated at a particular practice receive the surface treatment rather than a LASIK procedure.  In our practice it is about 10%.  Some paractices are performing ASA in upwards of 50% of their cases.  For some patients this can mean the difference between being able to have vision correction performed. If you have been told that you are not a candidate for LASIK, you may be a candidate for advanced surface ablation technology instead.  A comprehensive evaluation is the only way to find out if  ASA is best for you. www.dishler.com/pages/about-lasik