eyeCONNECTIONS
Using PRK for LASIK flap problems

PRK has become more and more popular for routine LASIK enhancements. For buttonholes and flap failures, PRK with mitomycin C (MMC) has always been the preferred approach. In the past I have waited for three months thinking that treating on a “settled” flap would give the best results. However, immediate action may be the preferred mode. We all need in our “tool belt” a method to handle flap mishaps. The following exchange may enhance our approach to enhancements.

Have any of you tried immediate PRK after a LASIK flap problem? I ask this question because just the other day, I had a partial buttonhole in the left eye of a young man. I replaced the flap without doing laser and told him we will have to wait three months before attempting to do anything on this eye again. He now has anisometropia (the right eye was done without complications) and has never worn contact lenses. Needless to say, he is not very happy to have to wait three months as he is struggling to work. All of this could have been avoided if I had done this immediate PRK technique.
I know there was a study related to PRK after LASIK flap complications reported in “Immediate transepithelial photorefractive keratectomy for treatment of laser in situ keratomileusis flap complications,” published in the March/April 2002 issue of the Journal of Refractive Surgery. The authors were V.K. Jain, T.G. Abell, W.I. Bond, and G. Stevens Jr. The article retrospectively analyzed seven patients (14 eyes) who had bilateral simultaneous LASIK. One eye in each patient had PRK performed for a flap complication. All seven patients had excellent visual outcomes at six months. Clive Novis, M.B.B.Ch.
South Africa

I did transepithelial PRK with MMC in a hyperopic patient. One eye was uneventful, and the other eye (+2.25) had a flap tear. I did the procedure 15 days later. The overcorrection was 2 D and unintended monovision. The patient was happy and had a best-corrected visual acuity of 20/20. I do not know the reason for the overcorrection.
Roberto Mansur, M.D. Buenos Aires

I had a buttonhole seven years ago in a physician’s wife who was –2.25 with about 0.75 of negative cylinder. I did nothing but observe her (no laser treatment), and at three months she was 20/20 uncorrected with an outcome of about –0.25 –0.5 x 180. Since she was in her 40s, we left her alone, and she has done great ever since. She had a terrible complication but had a great outcome. Everybody was happy.
Steven Safran, M.D. Lawrenceville, N.J.

I am one of the authors of the 2002 Journal of Refractive Surgery paper about immediate PRK over unfortunate flaps. Dr. Tom Abell and I reported a retrospective series of 14 eyes in which a microkeratome flap had been made but was not thought adequate for an ideal LASIK laser treatment for one reason or another. The irregular flap was then replaced on the corneal bed, and transepithelial PRK was performed at the same sitting. This was of course in the bad old days when the equipment was not as good, and making a flap was more of a chancy thing that it is now. The theory, such as it was, was that an irregular flap would have mirror-image irregularity in the bed, and putting them back together would be like putting a key back into a keyhole. Treating immediately rather than waiting for an arbitrary amount of time was thought to possess several advantages. It has seemed to me, over the years, that the conventional wisdom regarding the optimum amount of time that should elapse after making a less-than-ideal flap for that flap to heal somewhat and, with hope, stabilize before any further treatment, has owed more to philosophy and individual outlook than to science. The most common wisdom I have heard has been to wait three months—not two, not four—before any further intervention, but I have seen many other periods of time, including never, recommended as best and safest. 
In this study, Dr Abell and I examined our results after same-sitting PRK over irregular flaps. The results were excellent. Seven eyes (an admittedly small number) of seven patients had had immediate transepithelial PRK after not-optimal flaps. (The seven fellow eyes of the same seven patients had flaps that were fine.) The results were excellent, quite comparable with the uncomplicated fellow eyes, with a little higher chance of enhancement. Six of the seven best-corrected to 20/20 and the seventh to 20/30, implying that irregularity was not worsened. This was a small sample but perhaps one with which we could suggest limited and moderate conclusions.
There were several caveats that need to be emphasized: a) This issue of possible suboptimal flaps had been addressed in our pre-operative patient talks and specifically in our written consent forms. b) Flaps had to have basically regular surfaces after being replaced on the bed for this technique to be considered—represented in the small sample were buttonholes, free caps, and even suction-loss flaps that were quite irregular on the inner side, but all the flaps discussed in the paper were not mangled or folded, but had what seemed to be smooth regular surfaces after replacement on the bed. (An ideal case for this technique, for instance, would be a flap where the keratome, for reasons of its own in those days, had stopped in the middle, and the flap was regular but could not be raised past where the cut stopped.) After the flaps were replaced and looked as smooth and regular as possible, transepithelial PRK was done. c) I reveal my ignorance in not being sure when MMC began to be used frequently in PRK cases, but this was well before that time, and no MMC was used (and I do not think I would recommend it even now with this technique when the state of the cornea is necessarily uncertain). 
I have had personal good luck with this technique, and it is still in our informed consent, though I have not used it again since the paper was written. I have never seen the advantage in waiting for several months while the eye, and the patient, may change in unpredictable ways.
William Bond, M.D.
Pekin, Ill.

Dr. Bond, thanks very much for this useful contribution. I wish I had known about this technique a few weeks ago when one of my patients got a buttonhole in the left eye. It was not a complete buttonhole, so I think this technique would have worked well. Clive Novis, M.B.B.Ch.

Editors’ note: The physicians who posted messages here have no financial interests related to their comments.

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ABOUT THE AUTHOR

J.E. “Jay” McDonald II, M.D., is the eyeCONNECTIONS editor. He is director of McDonald Eye Associates, Fayetteville, Ark. Contact him at 479-521-2555 or mcdonaldje@mcdonaldeye.com. He has financial interests with Bausch & Lomb (Rochester, N.Y.).