What is LASEK? LASEK surgery (EK for short) is a new excimer laser procedure invented by Massino lamellion MD at Rovigo Hospital Ophthalmology Center in Italy in 1997 in the course of refractive surgery for high numbers with relatively thin corneas, which overcomes the pain of PRK, subepithelial clouding (HAZE) and the need for patients with high numbers to have surgery. It overcomes the pain, subepithelial clouding (HAZE), and corneal thickness for patients with high numbers of procedures, and will bring better visual outcomes for such patients. LASEK surgery steps 1, preoperative surface anesthesia with 0.5% Elcaine eye solution; 2, 8.5mm diameter ethanol solution mask placed on the cornea, inject 20% ethanol, hold for about 30 seconds, so that the ethanol into the epithelium and the anterior elastic layer to loosen the connection between the two; 3, balance fluid rinse ethanol; 4, using the hoe corneal epithelial separator to separate the flap to the edge of the cornea, followed by Laser cutting; 5, after cutting, the epithelial flap is reset with a corneal epithelial repositioner, aligned neatly, and a bandage type corneal contact lens is worn. Below, we explain in detail the procedure of LASEK surgery (EK). First, an alcohol marquee is placed on the corneal surface with 20% alcohol for 20-30 seconds, see the figure below. After the action of the alcohol, the corneal epithelium becomes looser and there is a potential separation plane in the basement membrane of the epithelium itself, which will be separated with the help of some small surgical tools. After the epithelial flap is separated, the excimer laser treatment is performed. After laser cutting, the epithelial flap is reset. Finally, a corneal contact lens (contact lens) is placed in front of the cornea to protect the cornea. The surgery is over. The patient can leave the hospital, go home, rest and apply eye drops as required. Many foreign scholars believe that LASEK is superior to PRK but not a substitute for LASIK, which involves creating a corneal epithelial flap, then performing excimer laser irradiation under the flap, and finally allowing the flap to reset. The original epithelial flap is shed and replaced by new epithelial growth within two weeks after surgery. Contact lenses should be worn for a few days after surgery, with more obvious pain, photophobia, tearing, and foreign body sensation for 3-5 days, so you will need to take a break from light and can only perform normal work after a week. LASEK surgery is performed by using an epithelial knife to cut out an epithelial flap with a thickness of 60-80 microns, a diameter of 8-10 mm, and a 30 degree curvature of the tip, and then lifting the flap and using an excimer laser to perform in situ grinding to change the refractive power of the cornea to correct myopia and astigmatism. The epithelial flap is then repositioned. After the surgery, the aberrations and glare problems can be solved for patients with ultra-high numbers. Since the epithelial flap thickness is 60-80 microns, it solves the thickness problem for patients with high acuity and relatively thin corneas, and also improves safety for these patients. LASEK surgery solves some of the problems that Lasik is considered a contraindication and offers hope for correction in some patients with ultra-high myopia and relatively thin corneas. In addition, there are some people who usually participate in more confrontational activities, such as professional athletes and police officers, who can be considered for EK surgery even if their corneal thickness is sufficient. Because EK surgery does not have a corneal stromal flap, there is no need to worry about trauma causing damage to the corneal flap after surgery. There are two main disadvantages of EK surgery: First, the post-operative recovery is slow, and it usually takes about a week before normal vision is restored. However, this time varies from person to person, and from some of my own experience, my post-operative patients are usually in pain within 3 days and can have their corneal contact lenses removed 3 days after surgery. The second disadvantage is that postoperative haze and corneal clouding may occur, so the postoperative medication takes longer, and the specific dose and duration of medication depends on the specific circumstances of each individual. Generally speaking, the younger the person and the higher the degree, the more likely he or she is to develop corneal clouding. In addition, people with scarring are not allowed to have LASEK surgery. In order to reduce the pain and slower recovery after LASEK surgery, a new surface cutting procedure has been applied and created: TransPRK surgery. This procedure removes the corneal epithelium and the corresponding stromal layer directly with the excimer laser without the need to immerse the corneal epithelium, resulting in less irritation and faster recovery after surgery.