Advantages of Bladeless (Femtosecond) Laser
Flap laser treatments are 2-stage treatments. In the 1st stage of the treatment, a thin flap called a flap that holds one edge of the cornea is removed. In the method called LASIK, this flap is removed with mechanical blades called microkeratome. In the method called intralasik, the flap is created using a laser technology called femtosecond laser, completely by laser and under computer control, without any knife touching the eye.
The most feared complications of excimer laser, which adversely affected vision, were related to the use of a knife in the first stage, the flap creation stage. For this reason, the bladed method has been abandoned worldwide and the bladeless method called intralasik has started to be used.
The knife used in the knife method is a tool that holds the eye with a vacuum and makes an incision on the eye in a closed system. Here, the blade rotates over the eye while making the incision, covering the eye and the surgeon cannot see the eye and the incision during the incision. In these incisions, unfortunately, when the knife is removed, there may be a puncture, tear, rupture or even perforation of the cornea in the flap, but unfortunately, the surgeon can see this after the incision is completed and it is too late, so there is no return.
However, since it is possible to monitor the incision process second by second on the computer screen in bladeless laser, this makes the procedure very reliable. With this method, there is no risk of flap rupture, tearing or perforation. In addition, since you watch the incision second by second, you have the chance to stop the procedure in case of the slightest mishap.
Another important difference between blade and non-blade methods is the thickness of the flap lifted over the eye. We prefer the flap that we lift over the eye to be as thin as possible. Since we lift this flap, which we call the flap, and apply laser to the underlying layer, we want to thin the substrate as little as possible and leave it as thick as possible at the end of the laser. Unfortunately, we do not have the chance to lift this flap very thin with the blade method, whereas with the bladeless laser, we can lift this flap very thin and ensure that the underlying layer remains thicker.
Moreover, it has been seen in studies with the blade method that even if you adjust the blade to remove a thin valve, the blade can remove this valve much thicker or much thinner than you calculate. It has been found that there may be a deviation of 100-150 microns from the set value in the blade incision. This is a very important point especially in thin corneas, you adjust the blade so that the patient's eye will have 300 microns of tissue after the laser, but if the blade cuts too deep, the remaining tissue can go down to 200 microns and the eye is at serious risk.
However, it has been found that the margin of error in bladeless incisions made with femtosecond laser is only 10 microns, which means a very reliable result.
Another difference between bladed and bladeless laser is the postoperative closure problems in the postoperative flap and the risk of tissue penetration under the flap, which we call epithelial walking. The blade makes a straight incision and when the valve is closed, the risks of the flap not being fully in place and what we call flap slippage and wrinkling are many times higher than the bladeless method. As a result of flap slippage or wrinkling, negative effects cause permanent vision problems in the patient. However, in the bladeless incision, the incision edges are vertical, angled, that is, in the bladeless incision, the valve sits on the bed underneath like the lid of a pot. Since the incision edges are angled and the flap fits like a pot lid, unwanted complications such as slipping, wrinkling and cell penetration under the flap are almost zero.
