What’s the first thought that comes to mind when you think about a flap coming loose after LASIK? If you’re like 99.9% of people, it’s something like, “Yuck.” If this was a Family Feud category, it would just have the one answer that all 100 people on the survey said unanimously. “First thought that comes to mind with a LASIK flap moving after LASIK? Survey says! ‘Gross! Never ask me that again! Ugh, sick!’” It would be an easy category to win.
Unfortunately, considering LASIK requires thinking through this specific complication. The majority of people deciding whether or not to have LASIK want to know about this possibility. And the reason I say “unfortunately” is because the chance of a LASIK flap moving after surgery is marvelously close to zero. That means the worry over it is wildly incommensurate with the possibility of it. Is it impossible? No. But almost nothing is impossible. In this case, the preoccupation about a LASIK flap moving would be like interviewing for a new job and — when asked if you’ve got any questions for the company — asking, “What are the chances that a helicopter will crash into the building while I’m working?”
Yes, okay yes, I see I went too far with that analogy. I was trying to communicate the idea of a concern that’s out of proportion to relevance for the topic at hand. Probably a better analogy would be asking about complications later in life from having your appendix removed. If one of your main questions was, “If I am stabbed in the belly in the exact spot where you removed my appendix, is there a chance that my appendectomy would alter the surgical plans to fix my stab wound?” Yes! I’m glad I took another swing at that one because that analogy is almost perfect.
Does the Flap Heal?
The old trope of “the flap never fully heals,” is the most dangerous type of factoid. Namely, it’s one of those pieces of information that is only partially true. And the part of it that’s true confuses, rather than clarifies, the understanding of the overall healing that happens after LASIK. It makes it seem like there is just some weird, loose layer of tissue that could be sneezed out of place. The healing of the flap after the procedure — and YES! it heals — is nothing like that. It would require a significant, lacerating injury to cause problems. (That’s why the appendectomy guy would have to ask about something like a stabbing.)
When people say the flap never heals, they’re speaking of the undersurface of the flap. What’s interesting is that this fact is a fortunate and essential feature of healing after LASIK. If the interface healed like that — where the undersurface of the flap healed down onto the surface beneath it — the whole interface would just turn opaque. Wherever a cornea heals, the collagen changes its alignment and it transforms from clear to opaque. In fact, if LASIK healed like that we wouldn’t even be having this conversation because LASIK wouldn’t exist.
So when I said a few lines above that YES! it heals, what was I talking about? Well, it heals in two ways:
• The first is a layer of epithelium that covers the edge of the flap to make the surface uniform across that margin.
• The second way it heals is the actual stroma (the “body” of the cornea that comprises 95% of the corneal thickness) fibroses and heals along the margin of the flap.
The reason I smile when people ask me about this topic in clinic is because I have lifted flaps hundreds of times to do laser retreatments (quick aside to soothe your concern and my ego: even if the enhancement rate is 1% or 2%, that adds up over the years). And lifting a flap, even with experience, and a microscope, and a special tool to do just that... it’s not easy. The healing of flap isn’t just a laboratory or theoretical histology discussion. It’s something I’ve personally experienced and had to overcome every time I’ve ever done a LASIK enhancement.
Because of this healing, it is almost impossible to move a flap after LASIK. I have seen many, many injuries to the cornea in the months and years after LASIK: from tennis balls, footballs, fingers, debris from hammered metal, elbows, and even toes. It’s taught me that even with a serious injury to the eye, which is required to have a chance of moving a flap, the LASIK flap is amazingly impervious to complications. It’s also taught me that no one owns safety goggles. For all the injuries I’ve seen, guess how many times I’ve seen a flap move? One time.
And with that, we can finally wrap this up. It seemed important to give you the background in order to get to the answer for the original question. What if my flap moves after LASIK? You fix it. The one time I saw it happen was for a patient three weeks out from LASIK who experienced the sharp fingernail of an 18-month-old daughter who would’ve felt bad about it if she could. It would’ve been a significant corneal laceration either way, but it moved the edge of his flap. I repositioned it the next day and he has been 20/20 in that eye since then. As a bonus, I believe he used up all his bad luck for at least a few decades when that happened. I’ve got to assume that man must be helicopter-proof at work nowadays.