Speaking of half femtoseconds, the most concerned problem for friends is the "corneal flap".
"Can a corneal flap heal?".”
"Does rubbing your eyes cause the corneal flap to displace?
"How to avoid the risk of valve complications?".”
Questions like this may have been turned in your mind thousands of times, and today, let's work together.
What kind of existence is a corneal flap?
Two types of lasers are used in femtosecond surgeryFemtosecond lasers are used to make flaps, and excimer lasers are used to cut。The reason for making a corneal flap is:In order for the excimer laser to precisely cut the stromal layer under the flapto achieve the purpose of correcting vision.
Half femtosecond has a high degree of personalization, high cutting accuracy, and saves corneal tissue more than full femtosecond.
These advantages are inseparable from the production of corneal flapspointsIf you think of corneal tissue as a watermelon, the corneal flap is a watermelon skin that can be lifted, and the stromal layer is the melon sac. Half femtosecond can be understood as "lifting the watermelon skin and accurately carving the inside of the melon sac".。Compared to the full femtosecond surgery that uses femtosecond laser "air" for interlayer blasting,A corneal flap is requiredHalf-femtosecond is more accurate and conserves corneal tissue
The cornea of the human eye can be divided into five layers: from top to bottomEpithelial layer, Descemet's layer, stromal layer, Descemet's layer, Endothelial layer
Half femtoseconds will come firstBlast is performed using femtosecond lasers in the epithelial, predescemet, and superficial stromal layersto cut out a pedicled corneal flapAfter opening, an excimer laser is used to precisely sculpt the matrix layer.
After the surgery,The epithelial tissue of the cornea repairs itself within 24-48 hours, usually after a few weeks for the epithelial cells and basement membrane to become firmly attached. But the front elastic layer does not have the ability to regenerateand fibroblasts are replaced after surgery.
In general,It takes 3-6 months for the flap to heal completely。The exact speed of recovery will vary depending on the individual's physical fitness.
First of all,Corneal flaps are always at risk of complicationsThis one is for sure. ButAt present, the technology of semi-femtosecond flap is very mature, and the corneal flap is not as fragile and easy to crack or open as we imagined
Today's femtosecond has been tempered and improved over time, and it is no longer used to make the flap with the traditional layer knife, but is usedFemtosecond laser technology flap making。That's how it was doneThe edge and thickness of the corneal flap are more uniform, the risk of valve complications is also greatly reduced.
In fact,The edges of the corneal flap made by femtosecond lasers are uniform, but not completely smoothLaser parameters such as flap thickness, diameter, side chamfer angle, etc., can be adjusted for the individual patientAn "in-locked" corneal flap is created to reduce more accurately and retains a certain amount of friction, making the healing relatively tight
Because of the existence of corneal flaps, we must pay special attention to eye protection when choosing half femtosecond. During the healing period of the corneal flapDon't rub your eyes violently, andFollow your doctor's instructions for eye medicine to promote recovery and avoid infection, especially noteAvoid strenuous exercise and confrontational activities, such as ball games, boxing, etc., to prevent the risk of complications such as valve displacement, folding, and dehiscence.