Excimer laser therapy for myopia was first used in clinic by American doctors in 1985. It developed rapidly in recent years and was introduced to China in the early 1990s. Excimer laser treatment of high, medium and low myopia is far superior to previous refractive surgery, so it has attracted the attention of ophthalmologists all over the world. But there are still many people who have doubts about this, fearing that their eyes will be punctured and burned. Generally speaking, excimer laser is ultraviolet light with short wavelength, which has photochemical effect rather than thermal effect with biological tissues, so it will not cause thermal damage, let alone burn. In addition, some people are worried about piercing the eyeball, which is unnecessary. Excimer laser has short wave length and weak penetration, and each pulse can only cut the depth of 0.25um, which is horizontal cutting under the cell, so the cutting is extremely accurate and it is impossible to pierce the eyeball. Some people worry that it will hurt other parts of the eyes, which is also a concern, because excimer lasers have infrared tracking systems. When your eyeball deflects beyond the normal range, the laser will automatically stop shooting to ensure the safety of treatment. The principle of laser treatment of myopia is: because the anterior and posterior diameter of the eyeball is too long or the anterior surface of the eyeball is too convex, the external light can not accurately converge on the fundus, which leads to myopia. Excimer laser corneal refractive treatment technology (PRK and LASIK technology) uses the computer-controlled excimer laser beam to slightly flatten the anterior surface of the eyeball, so that the external light can accurately converge and image on the fundus, thus achieving the purpose of correcting myopia. Excimer laser is an invisible ultraviolet beam excited by a mixture of fluorine and argon. It is a kind of cold laser, which can accurately ablate the desired part of the human cornea without damaging the surrounding tissues and other tissues and organs. When you decide to do myopia laser surgery, you must do a comprehensive and systematic eye examination, including: 1. Vision examination: including the vision without glasses and the best corrected vision with glasses. 2. Refractive examination: it includes three steps: initial examination, mydriasis optometry and re-examination. Whether the optometry degree is correct or not directly affects the surgical effect. 3. Examination of anterior segment and fundus: focus on whether there is scar in the transparent part of cornea, whether the lens is turbid, and whether there is vitreous opacity and fundus lesions in fundus examination. 4. Intraocular pressure examination: exclude the possibility of high intraocular pressure and glaucoma. 5. Corneal curvature examination: exclude the possibility of keratoconus and flat cornea. 6. Measurement of corneal thickness: the thickness of corneal center is less than 500. If the patient is highly myopic, pay attention to the cutting depth of corneal center before operation and explain the relevant situation to the patient. 7. Examination of corneal topography: The main purpose is to remove the regularity and symmetry of the whole corneal surface except for various abnormal factors. 8. Stop wearing contact lenses two weeks before the operation. Experts point out that the population suitable for excimer laser treatment is 18 to 50 years old, with myopia of 150 to 2000 degrees, or astigmatism of 100 to 400 degrees and hyperopia of 200 to 800 degrees in recent two years. People with systemic diseases such as infectious inflammation, keratoconus, glaucoma, cataract, fundus lesions or diabetes and collagen diseases are not suitable for excimer laser therapy. Expert warning:/kloc-laser treatment for myopia under 0/8 years old may be done in vain. Not long ago, a survey from Shanghai Ruijin, Changhai and other hospitals showed that students accounted for the vast majority of patients seeking excimer laser treatment for myopia, especially high school students, and the number of outpatient visits was increasing day by day. In this regard, experts remind: excimer laser treatment of myopia,1teenagers under 8 years old is not suitable. According to experts, in order to ensure safety and effectiveness, excimer laser treatment of myopia requires that the patient's refractive state is stable before operation and the corrected vision is above 0.5. Accordingly, the best age for surgery should be 25 to 35 years old. Teenagers under 65 years old, 438+08 are in the physical growth period, and the diopter of their eyes is unstable. If you operate blindly, your vision is likely to deteriorate after one or two years, which will seriously affect the expected curative effect. Laser treatment of myopia and its sequelae has become a popular method for many people who want to "take off their glasses". However, before doing this kind of surgery, they can use excimer laser keratectomy (PRK) and excimer laser in situ keratomileusis (LASIK) widely for laser treatment. In the refractive system of the eye, the refractive power of the cornea accounts for 70% of the total refractive power, and the slight change of the refractive power of the cornea can obviously affect the degree of myopia. PRK and LASIK can correct myopia by cutting the central cornea, thinning it and reducing its refractive power. PRK is mainly used to treat moderate and low myopia. However, due to the destruction of normal corneal anatomical structure, complications such as corneal opacity, glaucoma or high intraocular pressure, glare and regression may occur after operation. LASIK can maintain the normal anatomical structure of the anterior corneal tissue, reduce the subepithelial opacity and refractive regression caused by the healing reaction of corneal tissue after operation, with good prognosis, good postoperative recovery and stability, and is suitable for the treatment of moderate and high myopia and myopic astigmatism. But LASIK may also have complications, such as infection, undercorrection or overcorrection, corneal penetration, iatrogenic corneal astigmatism, secondary keratoconus, irregular corneal flap, glare and so on. If these complications are found in time and handled properly, most of them will not leave sequelae and will not affect the curative effect. However, some complications do hinder the recovery of vision, such as preoperative myopia and postoperative high myopia; Or no astigmatism before operation, high astigmatism after operation and so on. If the cornea left by the operation is too thin, it cannot be remedied by reoperation. Another example is corneal penetration during operation or severe keratoconus after operation, which may make patients have to undergo corneal transplantation and bring new troubles to patients. Moreover, eye laser surgery also requires age. If the age is less than 18 years old, it is not suitable for surgery, because people under 18 years old have incomplete eyeball development, unstable refractive state and unstable surgical effect. If you operate blindly, your vision is likely to deteriorate after one or two years. Therefore, both operations require patients to be between18 and 55 years old, and the myopia degree should be stable for more than 2 years. The best age for surgery is 25 to 30 years old. Severe dry eye, exophthalmos and eyelid insufficiency, glaucoma and monocular patients are absolute contraindications for surgery. Because glare may appear after the operation, drivers and other special professionals need to carefully consider the operation. Even if you have achieved good naked eye vision through surgery, you should check your fundus and vision regularly. Advantages and disadvantages of laser treatment of myopia With the continuous development of science and technology, the methods and means to treat and correct ametropia (ametropia includes myopia, hyperopia and astigmatism) are also changing with each passing day, including surgical methods, wearing RGP, OK glasses, wearing soft contact lenses and wearing frame glasses. Because many methods for treating ametropia are commercialized with the participation of many businesses. In commercial speculation, customers are lost by overwhelming advertisements. Nowadays, surgical methods are increasingly adopted by the younger generation of ametropia patients. In particular, some businesses only publicize their own advantages and downplay their own shortcomings. A typical example is the exaggerated propaganda of excimer laser surgery (PRK, LASIK, PTK) in the treatment of ametropia. Misguided by false advertisements, many patients think that this technology is omnipotent and have no idea about the possible sequelae and dangers. For example, a survey in the Department of Ophthalmology of a affiliated hospital of a medical university in Shanghai shows that many patients choose laser surgery just to get rid of their dependence on glasses; Some patients consider laser surgery from a cosmetic point of view. Respected authoritative medical experts believe that it is not worth the candle to perform laser surgery on normal eyes just to get rid of glasses or contact lenses. LASIK laser treatment of ametropia was put forward in 1990s, and it is the most commonly used one now. Before the operation, fundus examination, intraocular pressure measurement, A-mode ultrasound, corneal topography and refractive examination must be done, then preoperative surface anesthesia should be performed, a part of the cornea of the eye should be cut, the corneal stroma under the cut corneal flap should be cut by laser, and finally the cut corneal flap should be reset. Antibiotics and some hormonal drugs should be given priority to after operation. So, what are the advantages and disadvantages of laser surgery for myopia? Advantages of laser treatment of myopia: the effect is ideal for customers with moderate or low refractive error, and the rebound rate of myopia is low. You can avoid wearing glasses for a while through surgery. At present, the problems and disadvantages of laser treatment of myopia are also obvious: because this operation came out soon, ophthalmologists can't count and determine its long-term effect at present; Some patients need long-term eye drops after operation, otherwise their eyes will be dry and uncomfortable, and some even need to drop for a lifetime. In addition, the following complications are easy to occur during and after operation: 1, corneal flap eccentricity, corneal flap dislocation, corneal flap wrinkle, corneal interlayer debris or blood residue; 2. The laser cutting deviates from the center, and the corneal knife cuts through the cornea; 3, postoperative lifelong glare and glare: myopia is more common in high altitude areas, and things have halos; 4. Undercorrection or overcorrection: If this happens, re-operation, and the effect after the second operation is not ideal; 5. Vision rebound: especially in patients with high myopia, vision began to decline several years after surgery; 6, the best corrected vision decline: the vision that can be achieved when wearing glasses can not be achieved after surgery; 7. Dyslexia, dry eye, decreased corneal sensitivity and pain; 8. Irregular astigmatism: Almost all patients have irregular astigmatism in different degrees after operation. 9. Corneal infection, diffuse interlaminar keratitis, central corneal island formation: 10, peripheral corneal degeneration or scar formation, central corneal pigmentation. For the above reasons, most doctors are reluctant to do laser surgery for nearsighted people if they put aside their interests. No matter what the proportion of the above sequelae is, it will be a lifelong regret and misfortune if any one of the complications falls on the patient who has undergone this operation. Because we only have a pair of eyes, light is priceless. More dangerously, according to strict medical regulations, keratome can only be used in one eye. But now, in some hospitals or myopia treatment centers, in order to obtain high profits, a corneal knife is reused, just as it is often reported that hospital dialysis tubes are reused. So before doing this operation, don't just listen to one side's one-sided words, you must seriously consider and weigh them repeatedly. On the other hand, this kind of operation is expensive, costing thousands of dollars. I hope that the majority of ametropia patients will carefully weigh the pros and cons before acting.