Welcome to our Cover Focus on enhancement surgery. We typically consider enhancement as occasionally being needed to correct a residual refractive error after laser vision correction; however, in this age of presbyopic correction and refractive lens exchange, indications for enhancement surgery have widened. Looking back at the days when I first started doing laser refractive surgery, in 1994, my enhancement rate was about 15%. Performing enhancements was part and parcel of refractive surgery, and we appropriately informed patients there would be a high probability of requiring an enhancement.
So what changed? First, technology got better, with improved excimer laser heads delivering predictable outcomes, eye trackers to measure eye position and movement during surgery, and wavefront treatments to offer patients customized procedures. Then along came femtosecond lasers, reducing the variability of biomechanical changes induced by flap creation.
We did not think twice about performing enhancements in the early days of refractive surgery, but now, for some doctors and certainly for patients, performing an enhancement is seen as akin to a mini-disaster. Luckily, enhancement rates are lower today than ever before. When a touch-up is needed, however, a variety of surgical procedures can be performed to ensure that the patient walks away from the clinic fully satisfied. In this issue, surgeons share strategies for enhancement after LASIK, PRK, and cataract surgery and offer advice for patient counseling.
A case of epithelial ingrowth, which seems to occur more frequently in flaps that have been created with femtosecond lasers, is described by Paula Verdaguer, MD; Jose L. Güell, MD, PhD; Daniel Elies, MD; Oscar Gris, MD, PhD; and Felicidad Manero, MD. They lifted the corneal flap and cleaned the epithelial ingrowth from the interface. Several strategies have also been proposed to reduce the formation of epithelial ingrowth, including use of a contact lens, as suggested by Co-Chief Medical Editor Erik L. Mertens, MD, FEBOphth, and the use of a tissue adhesive on the surface, as suggested by Associate Chief Medical Editor Arthur B. Cummings, MB ChB, FCS(SA), MMed (Ophth), FRCS(Edin). I would like to add four more pearls: (1) perform enhancement at 3 months rather than later when the flap is not as rigid, (2) ensure a clean flap lift without ragged edges and epithelial loss, (3) prolong drying, and (4) prescribe frequent lubrication postoperatively. It makes sense for patients to be seen on day 1 and again 1 week to 10 days following an enhancement and to treat epithelial ingrowth early rather than later following the methodology described by Verdaguer, Güell, and coauthors.
One proposal for enhancement following LASIK is to perform PRK or LASEK on the surface of the flap accompanied by the use of mitomycin C. This is an attempt to eliminate the risk of epithelial ingrowth. As Chief Medical Editor, I am permitted to express my opinion: This method of enhancement as a routine approach makes little sense. Regression, a major reason for enhancement, has in many cases been attributed to epithelial hyperplasia. In performing surface ablation, the epithelium is removed, as with PRK, or replaced, as with LASEK (where more than 50% is probably dead epithelium); an ablation to correct the regression is performed; and mitomycin C is then applied. There is great hope and faith that the surface will epithelialize and become hyperplastic in the same manner as prior to the enhancement. That is a lot to hope for, especially with concurrent use of mitomycin C. I would be happy to consider basic science studies on wound healing to substantiate this course of action; however, in my role of troubleshooter providing second opinions, I have come across many patients who sustained over-correction with this type of enhancement for regression in myopic and hyperopic LASIK.
In this day of presbyopic correction, enhancements are moving into another dimension. Robert Edward T. Ang, MD, discusses enhancements for several presbyopic corrective technologies and provides his helpful perspective. Piggyback lenses and phakic implants are exciting options, particularly in those who have had prior lens surgery or dry eye disease. I believe these will play a much bigger role in the future, as they provide an option of correcting spherical error and astigmatism and also supply mulifocality. Furthermore, the correction is reversible, offering the potential for changes in the future.
Finally, as stressed by several authors, avoidance of enhancements is key, and obtaining near-perfect outcomes can be accomplished through use of new technology, attention to detail, and careful audit to ascertain why a lessthan- ideal outcome has occurred and avoid its repetition. Patients entrust us with their care and have increasingly higher expectations. Our roles are both to manage their expectations and to provide the best possible outcomes. In the hopefully rare event that we fail, we must find a way to resolve this without complication—our collective (doctor and patient) pursuit of perfection.