TransPRK is a type of keratomileusis and is a surface cutting procedure, TransPRK can be called “trans-epithelial laser keratomileusis”, its main feature is to use only one excimer laser to remove both the corneal epithelium and the anterior corneal stroma to complete the change of corneal morphology and achieve refractive correction. The aim is to achieve refractive correction. More than a decade ago, some foreign surgeons tried to use TPRK to achieve “total excimer laser surgery”, i.e., the excimer laser is used to remove the epithelium first in PTK mode and then to cut part of the cornea in PRK mode. The reason for the wide variation in outcomes reported in these studies is mainly due to the setting of the amount of epithelial cut, as PTK only removes a uniform thickness of tissue such as 50 or 60 microns, which is not the case with the actual corneal epithelium. If the set amount of epithelial cut is lower than the actual thickness, the effective corrective optical area will be reduced, resulting in visual quality problems for some patients. In addition, a uniform thickness cut will result in “hyperopic drift,” which introduces a certain amount of additional hyperopia and misaligns the refractive correction. In 2008, Reinstein et al. reported that the average thickness of the cornea was 53 microns in the center and 58 microns in the periphery at 6 mm diameter, showing a pattern of central to peripheral thickening, as measured by UHF ultrasonography. As a result, TransPRK, the only international all-excision laser procedure that conforms to this natural thickness pattern of the corneal epithelium, was introduced in Europe in 2009. It sets a gradual epithelial cutting model of 55 microns in the center and 65 microns in the periphery, and de-epithelializes while approximating to achieve +0.75 D farsightedness correction, avoiding farsightedness drift and actually removing the epithelium refractively, which overcomes the PTK This overcomes the defects of PTK epithelial removal. TransPRK is suitable for most people with low to moderate myopia and hyperopia because the entire procedure can be completed with the excimer laser alone, without the need for a flap. TransPRK is a one-step, high-speed cutting procedure with short operating time, small trauma surface, fast healing, avoiding the risk of haze, and significantly less post-operative pain than traditional PRK surgery, and the procedure is safe (the safest among several types of refractive surgery), especially for young people who love outdoor sports. Currently, most excimer lasers are not specifically prescribed for TransPRK. The only excimer device on the market that can do the TransPRK procedure is the Amaris excimer laser. The Amaris Excimer has a fast laser frequency of 500Hz or 750Hz and incorporates a six-dimensional tracking feature that specifically simulates the thickness of the corneal epithelium and is designed for the TransPRK procedure. Other excimer devices have not yet developed software specifically for this surgical approach, and some doctors do combined PTK+PRK surgery with the help of other devices, but they are not yet able to fully implement TransPRK due to flaws in the design of the device itself.