First things first, all-laser LASIK is better than LASIK with a blade. I don’t even need an asterisk or a footnote when writing that sentence. It’s important to state that clearly here at the beginning because opinions and facts are notorious for becoming interchangeable. Today’s topic has been through enough rigorous scientific study to be a fact.
It wasn’t always so. There was a period of time for the first few years after all-laser LASIK debuted where there were equal and opposing opinions on whether the traditional method with a blade called a microkeratome was still the better option. What changed since then? Lasers! These types of lasers are driven by computers, and computers seem to get about a decade more advanced every year. Once modern levels of speed and precision started to arrive with all-laser LASIK, large studies clearly showed it was a fact that it was safer and more accurate than LASIK with a blade. Do opposing opinions still exist? Absolutely. But there are also people who believe the moon landing was a hoax. (Remember when Buzz Aldrin punched that moon landing conspiracy theory guy in the face when he wouldn’t stop harassing him? You should watch the video, but be warned: viewing it will turn the clothes you’re wearing into American flags.)
Let’s tackle these two improvements of safety and accuracy one by one. The change in safety is probably the most dramatic difference. A huge, nationwide study was done comparing complications in LASIK before and after the introduction of all-laser AKA bladeless LASIK. It was stunning to see the decrease. The reduction was about 90%. That means the chances of having a problem with LASIK were 10 times higher when a blade was still involved. To add to this, the complications that we still have are of a much different nature now. The risk of having a complication of catastrophe (worse vision, major injury, etc) is really close to zero now. I’ve literally never had that happen to a patient. It’s that low. The complications we see now are what I call complications of inconvenience. It usually means the procedure is delayed a week or two, or maybe there are drops used for longer than normal. It’s a different world than the days when a blade was involved.
For precision, the main factor is the creation of the flap. A laser still creates a flap, but it would almost be more accurate to say it creates a plane in a natural layer of the cornea. Your cornea has layers to it like an onion does. And where a blade would cut through — like if you cut the side of an onion with a chef’s knife and saw the rings — a laser separates a natural layer. If we compare it to the onion, it is more like separating a layer of onion than cutting straight through several of them. Because that flap — or layer — is so even, there aren’t varying mechanical forces affected by the change. When a blade cut more deeply through some layers at the edge, the resulting loss in tensile strength of the cornea could cause some “sag” and increase the effect of the laser unpredictably. It caused more shape change to the cornea than intended in some cases. The layer created with a laser is uniform throughout down to the level of thousandths of a millimeter.
There are boatloads more science behind the differences of all-laser LASIK vs. LASIK with a microkeratome. It becomes uninteresting enough wading through it all that even I, a complete nerd, realize it makes for poor reading. But all of it revolves around those two main points: safety and precision. If it was only one of the two, I’d have the same opinion on this. The fact that it is both solidifies that opinion even more. But my opinion doesn’t matter, because it’s a fact.