A: Generally, after 18 years old, the myopia degree is stable for about two years, there are no other organic diseases in the eyes, and the corneal thickness is sufficient.
Q2: What are the types of refractive surgery? What is the difference?
There are the following:
PRK excimer laser keratectomy
PRK surgery is to directly cut the corneal surface with excimer laser to correct myopia in different degrees. The deeper the incision, the more complications such as retrogression and atomization occur after operation. Therefore, it is not suitable for correcting high myopia, the epithelium is scratched, and patients have obvious pain a few days after operation. photorefractive keratectomy
This method keeps corneal epithelial layer and anterior elastic layer, so it conforms to the anatomy and physiology of cornea and becomes an advanced technology to treat ametropia in the world today. The operation is suitable for all kinds of myopia and hyperopia astigmatism with 150 ~ 2000 degrees, especially for patients with relatively thin cornea, and it takes more than one week to recover after operation. In addition, it is not recommended to give priority to patients with dry eye because of the need to make valves during operation; Rubbing eyes hard, strenuous exercise and contact collision may all cause corneal flap displacement; Corneal epithelial cell hyperplasia; If antibiotics are used unreasonably after operation, corneal flap infection may occur; Some people may be under-corrected or over-corrected after surgery.
Semi-femtosecond surgery (standard femtosecond)
Advantages: Semi-femtosecond surgery is the most advanced surgical method in the world. Using femtosecond laser equipment to make open corneal flap has higher accuracy, thinner flap thickness and less risk, which basically avoids the risk of mechanical knife making corneal flap.
Disadvantages: the incision is large, 20-24 mm; Can't accept the strong impact of the outside world; Be careful when doing extreme sports.
Full femtosecond surgery
Advantages: Full femtosecond surgery does not need to make an open corneal flap and does not involve excimer laser. Instead, a full femtosecond laser therapeutic instrument is used to completely shape the corneal stroma to be cut through secondary interlaminar blasting at different depths in the cornea, and then it is taken out through a small incision of 2-3mm to complete the operation. Because "full femtosecond" surgery does not require an open corneal flap, the corneal diopter is really adjusted by "cutting". Full femtosecond surgery is more accurate, safer and more comfortable than semi-femtosecond surgery, and the postoperative recovery is faster. Disadvantages: 1 The range of treatment is limited: all femtoseconds cannot treat hyperopia.
2. Because two layers of laser fly on the cornea, more corneal tissue will be lost when flying halfway, with a difference of about 10 micron.
Note: It usually takes 2-8 hours to restore vision after laser surgery. Foreign body sensation, photophobia and tears are all normal reactions after surgery.
ICL crystal implantation
Advantages of ICL: intraocular lens is light and soft. Because ICL is light and soft, it can be folded into a very small size. It can be implanted into the eye through a small incision in the cornea. The whole process only takes a few seconds and there is no pain. After implantation, ICL unfolds in aqueous humor between iris and lens. ICL material is close to artificial natural crystal, which has good compatibility with human tissues and strong ultraviolet absorption ability. ICL intraocular lens does not affect the appearance. The role of ICL is similar to that of contact lenses. The difference is that ICL is implanted in the eye, while contact lenses are on the surface of the eye. You can't see ICL from the outside. The only change that can prompt you to implant the crystal is the improvement of your vision. Once implanted in the eye, you can neither see nor feel the crystal. ICL intraocular lens can be removed. The lens can be permanently implanted in the eye, but it can be removed if necessary. The lens does not cause any structural changes in the eye or cornea. It does not need to remove corneal tissue, does not change the natural state of the eyeball, and is reversible. It is suitable for the correction of myopia of 200~2000 degrees, hyperopia 1000 degrees and astigmatism of 500 degrees. Because of its high safety and good postoperative visual quality, it is considered to be superior to laser myopia correction technology, and it is also a new trend to correct ametropia in the future. If you have a high degree of ametropia, or are not suitable for corneal excimer laser surgery because of thin cornea, dry eye and large pupil, ICL will be your better choice.
Disadvantages of ICL:
Because ICL is in the gap between the anterior chamber and iris, such as long-term contact with extreme sports (such as roller coaster) after operation, it may lead to the rotation of the lens in the eye and the displacement of astigmatism, resulting in poor vision; Secondly, the structure of eyeball may change with age. If the gap is narrowed, the ICL crystal will rub against its own crystal for a long time, which will cause other eye diseases for a long time, but there is no need to worry too much when choosing ICL patients, because such problems can be completely avoided.
Regular examination according to the doctor's advice after operation can effectively prevent and put an end to the above situation. If there is discomfort, ICL can stop in time, which will not lead to this situation. Many patients feel that their postoperative vision is very good, so they give up regular examination, which is wrong. In order to keep their eyesight clear and healthy forever, they should go to the hospital for observation on time.
Q3: Will myopia rebound after surgery?
Generally speaking, the main cause of myopia is that the length of the eye axis is elongated and the image falls in front of the retina. When an adult matures in all aspects, the length of the eye axis will not become longer under normal eye use, so generally speaking, you will not rebound after a complete flight operation. Of course, the premise of not rebounding is to use your eyes scientifically after surgery.
Q4: How many degrees of myopia can full femtosecond correct? Can astigmatism be corrected?
All femtoseconds can correct myopia within 900 degrees, but if the cornea is thin, it may only correct myopia of about 500 degrees. Some people can't have surgery because their corneas are thin. So specific to everyone, how much myopia can be corrected depends on his corneal thickness. Astigmatism can be corrected up to 500%.
Question 5: Is 5:ICL safe to operate?
ICL surgery has been developed internationally for nearly 30 years. ICL entered China in 2006, and so far, the postoperative effect is very good. Icl crystal is exclusively produced by Swiss Starr Company. The material is hydrogel polymer of collagen fiber, which is a patented product and can exist in the eyes permanently without fear of rejection. You can work, read and study the next day after operation. But be sure to order the potion on time according to the doctor's advice and pay attention to eye hygiene.
Q6: What is the range of correction of myopia by CL?
The latest V4C crystal is suitable for myopia: -0.5D to-18D, astigmatism: +0.5D to +6D, and can also correct mixed astigmatism.