Principles of Myopia Surgery

Laser surgery for myopia is the most common and most effective method of treating myopia. Its principle is to make a corneal flap and use laser to adjust the refractive power of the cornea, so as to correct the patient's vision. Its treatment method is relatively simple and the accuracy of the treatment is relatively strong, which can avoid damage to other tissues of the eye. Therefore, it is welcomed by the majority of patients. Let us learn about this aspect below.

Optical transmission principle

Before the operation, the doctor enters the patient's basic information and surgical data into the computer (including the depth of laser focus, that is, the distance from the bottom of the cone lens to the laser focal point; the diameter of the corneal flap, the size and width of the pedicle; the energy of laser cutting, etc.). During the operation, the doctor operates the femtosecond laser machine and fixes the cornea with a cone mirror to maintain the precise distance from the laser head to the laser focal point in the corneal tissue. The depth of laser focus is the distance from the bottom of the conical lens to the laser focal point. The femtosecond laser machine transmits laser pulses according to the mode set by the doctor to perform various targeted cutting on the cornea. In short, what impressed us most about the optical transmission principle of femtosecond laser is the precise directionality and precise positioning of optical transmission.

Principle of light blasting

The laser pulse is focused into the corneal tissue to produce a light explosion; each pulse of light explosion produces a micro-ion, and each micro-ion evaporates approximately 1 micron of corneal tissue; the evaporation of corneal tissue produces expanded blisters and CO2 bubbles, which are absorbed by the corneal tissue, thereby separating the corneal tissue. The computer-controlled optical transmission system generates thousands of laser pulses, which are focused at the same depth in a dense, equal-width, and equal-spacing fence-wall grating pattern, producing light explosions and forming a layer of tiny-diameter bubbles in the corneal tissue, separating the corneal tissue and forming a corresponding separation surface, which is the cutting surface of the femtosecond laser. This cutting pattern is used to form horizontal separation planes and vertical planes when creating a corneal flap during LASIK surgery. Laser pulses can also be stacked and focused at any angle and any range in the corneal tissue to form tissue separation at different angles and ranges. Therefore, femtosecond laser can perform flake cutting on the cornea in corneal transplantation and LASIK surgery to produce exquisite grafts and corneal flaps; it can also perform point carving on the cornea to create tunnels in corneal stroma ring implantation surgery.

Myopia surgery has been developed for twenty years and the technology is already very mature, but not all myopia can be treated with surgery.

The prerequisites for myopia surgery are:

1. The age must be above 18 years old. Myopia patients under 18 years old are still in the stage of visual development. Myopia can be treated with medication. It is generally recommended to take Lejing Vision Nutrients, two packs a day. If you take it for a period of time, your myopia will be reduced, your vision will be improved, and you will not need surgery after adulthood. 2. Myopia degree is between 100-1500 degrees, astigmatism degree is within 400 degrees, and vision has been stable for more than two years. 3. No other ophthalmic diseases that will not affect postoperative recovery. 4. The thickness of the cornea is thick enough. After preoperative examination, surgery can be performed only if the patients meet the surgical requirements.