Laser Myopia Surgery (Full Femtosecond)

There are two principles of femtosecond laser surgery, one is the principle of light transmission, and the other is the principle of light blasting. First, look at the principle of light transmission in femtosecond laser surgery: Before surgery, the doctor inputs the patient's basic information and surgical data into the computer (including the depth of the laser focus, that is, the distance from the bottom of the cone lens to the laser focus point; the corneal flap Diameter, size and width of the pedicle; energy for laser cutting, etc.). During the operation, the doctor operates the femtosecond laser and uses a cone to fix the cornea, thereby maintaining the precise distance of the laser head to the laser focus in the corneal tissue. The depth of the laser focus, that is, the distance from the bottom of the cone lens to the laser focus point, the femtosecond laser transmits laser pulses in a mode set by the doctor to perform various targeted cuts on the cornea. Treatment of diseases: myopia myopia Indication Myopia laser surgery is not always suitable for all. First of all, it depends on whether the patient has the following conditions: First, the age is over 18 years old and under 45 years old. Second, there are no serious diseases in the eye. Third, the degree of myopia is relatively stable. Fourth, after the myopia degree is matched, it is also necessary to check the thickness of the cornea of the eye. For example, the patient has a myopia of 1000 degrees, but the cornea of the eye is too thin, which is not in accordance with the conditions for surgery. The corneal thickness cannot be lower than 450 microns. In addition, patients should also be excluded from systemic connective tissue disease and severe autoimmune diseases, and wear contact lenses for more than two weeks. The safety of laser treatment of myopia surgery, postoperative recovery, visual quality, and detailed preoperative examination are inseparable. Contraindications There are major diseases in the eye. Preoperative preparation First, eye examination Includes naked eye vision and wearing glasses for best corrected vision. Second, intraocular pressure examination To rule out the possibility of high intraocular pressure and glaucoma. Third, refractive examination Including computer optometry, medical optometry and dilated optometry three steps. Whether the optometry is correct or not directly affects the surgical outcome. Fourth, the anterior segment and fundus examination Focus on the corneal transparency, whether the cornea has scars, whether the crystal is turbid, whether the fundus is opaque or fundus lesions. Five, wavefront aberration check In addition to low-order aberrations such as myopia, hyperopia, and astigmatism, there are still high-order aberrations that seriously affect visual quality, and high-order aberration data is collected as a basis for diagnosis and surgery. Six, corneal curvature examination Eliminate the possibility of keratoconus and flat cornea. Seven, corneal thickness measurement If the patient is highly myopic, you should pay attention to the depth of the corneal center and explain the situation to the patient before surgery. Eight, corneal topographic examination The main purpose is to understand the regularity and symmetry of the entire corneal surface, and to exclude abnormal conditions such as keratoconus. Surgical procedure 1. Anesthesia eye. At the beginning of the operation, anesthetize the eye drops first. Use a special anesthetic to drip on the eyeball, let it lose pain, but the touch will still exist. 2, the corneal flap. First, the device is used to help the patient blink during the entire laser treatment of myopia surgery. Then the doctor put a suction ring on the opened eyeball to make the corneal flap. The process is only a few seconds, and the patient may feel pressure on the eye, or short-sighted vision, darkness and some pain. 3, laser carving. After the corneal flap was made, the doctor gently opened the corneal flap with a triangular sponge and used the laser to perform the engraving on the cornea according to the data of the laser instrument. The cutting area with a deep degree of myopia is correspondingly larger and takes a little longer. There will be a string of light and a little burning odor, the patient does not have to worry, this is a normal photochemical reaction when the laser works. Also note that although the laser can track the subtle activity of the eyeball in 1/10 second, it is best to keep an eye on it as required by the doctor. After the carving, the doctor covered the corneal flap with a sponge and rinsed the eyes. The operation of such an eye is done, and then the same step is used to make the other eye. 4. The operation is completed. The doctor will use a slit lamp microscope to examine the flap restoration. complication Eye pain, dry eyes.