Source: China Eyeglasses Online Author: Yu Yongxin
With the continuous development of science and technology, the methods and means of treating and correcting refractive errors (refractive errors include myopia, hyperopia, astigmatism) are changing day by day with the surgical method, RGP, OK lenses, soft contact lenses, frames and so on. . Because many refractive error treatments are involved in many businesses, they are highly commercialized. Under the commercial hype, customers are disoriented by the overwhelming advertising campaigns. Nowadays, surgical methods are more and more adopted by young refractive error patients, especially that some merchants only publicize their advantages and downplay and blur their shortcomings, a typical example is the exaggerated propaganda for excimer laser surgery (PRK, LASIK, PTK) to treat refractive error, and under the misleading of untruthful advertisements and propaganda, many patients think that the technology is omnipotent and are completely ignorant of the possible sequelae and dangers it may produce. The patients are completely unaware of the possible after-effects and dangers of the technology.
For example, a survey conducted by the Department of Ophthalmology of a hospital affiliated with a medical university in Shanghai showed that many patients chose laser surgery purely to get rid of their dependence on eyeglasses, while some considered laser surgery from the perspective of cosmetic surgery. Highly respected and authoritative medical experts believe that laser surgery on normal eyes simply to get rid of eyeglasses or contact lenses is not worth the cost.
LASIK laser treatment of refractive error was proposed in the 1990s and is now the most commonly used. Before the operation, it is necessary to do fundus examination, measurement of intraocular pressure, A-type ultrasound, corneal topography and refraction, etc., and then preoperative surface anesthesia, cut a part of the cornea of the eye, under the cut corneal flap, that is, the stroma layer of the cornea to do the laser cutting, and finally, the cut part of the flap to reset, and postoperative points of antimicrobial agents and some hormone-like medicinal drops.
So what are the advantages and disadvantages of laser surgery in the treatment of myopia?
The advantages of laser treatment for myopia: better results for low and moderate refractive errors, low myopia rebound rate, and temporary glasses-free for a period of time through the surgery.
The problems and drawbacks of laser treatment for myopia are also very obvious: because this surgery has not been introduced for a long time, ophthalmologists are not yet able to count and determine its long-term effects; some patients have to order eye drops for a long time after the surgery, otherwise their eyes will be dry and uncomfortable, and some of them even have to order eye drops for the rest of their lives. In addition, the following complications are likely to occur during and after the surgery:
1, off-center corneal flap, poor alignment of the flap, corneal flap folds, corneal interlaminar debris or blood residue;
2, off-center laser cutting, corneal knife cut through the cornea;
3, lifelong post-operative glare and dazzle: it is more common in the high number of myopia, and there is a halo when you look at something;
4, the eye is not always clear, and there is a lot of light. Halo;
4, undercorrection or overcorrection: this situation will be re-opened, and the results are not very good after re-operation;
5, vision rebound: especially for highly myopic patients, vision began to decline a few years after the operation;
6, best-corrected visual acuity decline: after the operation can not reach the vision that can be achieved when the glasses are equipped with glasses;
7, reading difficulties, dry eye, corneal sensitivity, and so on. Dry eye, decreased corneal sensitivity, pain;
8, irregular astigmatism: almost all patients have irregular astigmatism to varying degrees after surgery.
9. Corneal infection, diffuse interlaminar keratitis, and central corneal island formation:
10. Peripheral corneal degeneration or scar formation, and central corneal pigmentation.
Based on all the above reasons, if you put aside the tendency of profit, most doctors are reluctant to perform laser surgery on myopic people. Regardless of the incidence of the above sequelae, if any of the many complications fall on a patient who has undergone this surgery, it will be a lifelong regret and misfortune. Because we only have one pair of eyes, light is priceless. What is more dangerous is that, according to strict medical regulations, a corneal cutter can only be used for one eye, however, nowadays, some hospitals or myopia treatment centers, in order to gain high profits, reuse a corneal cutter, just like the frequent reports of hospitals reusing dialysis tubes. Therefore, before undergoing this surgery, do not listen to the words of one party alone, but consider them carefully and weigh them over and over again. On the other hand, this surgery is expensive, costing thousands of dollars, so refractive error patients should carefully weigh the pros and cons and think twice before doing it.
References: 1, Wang Kang Sun "ophthalmic laser new technology" (People's Military Medical Press, March 2002)
Author unit: Shenzhen Dr. Optical Co. Reference:
/bangda/read.php?wid=43Laser treatment for nearsightedness has become a popular choice for many people who want to "take off their glasses. However, it is important to be aware of the possible after-effects of the procedure before having it done.
Currently, laser treatments mostly use excimer laser keratomileusis (PRK) and excimer laser in situ keratomileusis (LASIK). In the refractive system of the eye, the refractive power of the cornea accounts for 70% of the total refractive power, and a mild change in the refractive power of the cornea can significantly affect the degree of myopia.PRK and LASIK are two kinds of surgeries precisely through the cutting of the central cornea, so that the cornea becomes thinner and reduces the refractive power of its refractive power to achieve the purpose of correcting myopia.PRK is mostly used in the treatment of low and intermediate myopia, but due to the damage to the normal anatomical structure of the cornea, the postoperative period can appear LASIK can maintain the normal anatomical structure of the anterior corneal tissue, reduce the post-operative corneal tissue healing reaction caused by sub-epithelial turbidity and refractive regression, with a better prognosis, post-operative recovery and stability, suitable for the treatment of moderate to high myopia and myopic astigmatism. However, LASIK may also have complications, such as infection, undercorrection or overcorrection, corneal penetration, medical corneal astigmatism, secondary conical cornea, corneal flap irregularity, glare and so on. If these complications are detected in time and handled properly, most of them will not leave sequelae and will not affect the efficacy of treatment. However, there are some complications that do hinder vision recovery, such as preoperative myopia that becomes high myopia after overcorrection; or preoperative astigmatism that is not present before surgery but becomes high astigmatism after surgery, and so on. If the cornea left by surgery is too thin, reoperation cannot be used to remedy the situation. For example, intraoperative corneal penetration or postoperative secondary severe conical cornea may cause the patient to have to undergo corneal transplantation, bringing new problems to the patient.
Additionally, there are age requirements for laser eye surgery. If you are younger than 18 years old, it is not suitable for you to do it, because the eyeballs of people under 18 years old are not fully developed, the refractive state has not been stabilized, so the effect of the surgery is also not stable. If you undergo the surgery blindly, your eyesight will most likely regress after one or two years. Therefore, both surgeries require the patient to be between the ages of 18 and 55, with myopia stabilized for at least 2 years. The best age for surgery is 25 to 30 years old. Severe dry eye disease, proptosis and eyelid closure insufficiency, glaucoma, and patients with one eye are absolute contraindications to surgery. Specialty occupations such as drivers need to consider the surgery carefully because of the possibility of postoperative glare. Even if good naked eye vision is achieved through surgery, the fundus and vision should be checked regularly.
Survey on safety of myopic laser surgery
About 10% of patients who have myopic laser surgery need to "go back to work". This figure is basically consistent with the 10% failure rate published in the British journal Ophthalmology. In some hospitals with poor conditions, the success rate is even lower than 70%. So how safe is myopic excimer laser surgery?
Surgery like magic
At 2 p.m. on May 19, the refractive surgery department of the eye center of Peking Tongren Hospital. As usual, the 30-square-meter waiting room was packed with patients. They are not ordinary eye patients, but a group of people who are medically known as refractive abnormalities, myopia, hyperopia or astigmatism - in which incoming light rays cannot be focused on the retina after being refracted by the cornea and crystals.
Here, excimer laser surgery will reshape the curvature of their corneas. Surgeons use an invisible light with wavelengths within the ultraviolet spectrum, which breaks the molecular bonds of corneal cells with great precision, vaporizing the corneal tissue without the slightest thermal damage to other tissues.
The operating room officially opened at 1 p.m. and did so until nearly 5 p.m. ended. This reporter saw a group of a dozen or so patients fishtail in and out of the room.
Despite the fact that the surgery required delicate skills like carving and polishing jade, the time was unimaginably short. From eye anesthesia to the end of the procedure, it takes only about five minutes. A nurse in the examining room said the total **** done this afternoon was 60 patients, "pretty much every day, or 20-30 on lesser days."
The walls of the waiting room are covered with "patient information". An article, "Currently Widely Performed Excimer Laser Surgery," describes that of the three types of surgery, excimer laser keratomileusis (PRK), excimer laser subepithelial keratomileusis (LASEK), and excimer laser in-situ keratomileusis (LASIK), the one that has the widest scope of application and has been proven clinically to be the safest and most effective is LASIK.
Myopic patient from Hebei province Liu Xiaoming was in the last batch of the day. Two days ago, she traveled from her hometown to Beijing Tongren Hospital for a checkup, and after ruling out various contraindications to surgery, the doctor chose LASIK for her. The surgery cost her half a year's salary: 4,368 yuan for one eye, plus pre- and post-surgical checkups and medication, totaling **** around 9,500 yuan. And if it had been done in her hometown, she would have saved at least 3,000 yuan.
"I didn't dare to do it in a small hospital, and didn't they say recently that a lot of people who have had this surgery need to return to work?" She said, having just walked out of the operating room.
The next day, she found that she no longer needed to wear glasses when watching TV, and on the phone she was overjoyed, "It's really like magic, the doctor said that my vision can return to 1.2." but then she began to worry about the rumors.
Returns worrying
The news of the "return wave" first came from Shanghai, where radial keratotomy (RK) for nearsightedness was all the rage 15 years ago. But a few years later, many patients who underwent the procedure began to experience serious post-operative complications that caused their vision to regress. In the ophthalmology departments of some tertiary hospitals in Shanghai, the number of redo surgeries exceeds 600 in a year and is increasing at a rate of 20 percent a year, the media said.
In Beijing, the situation is equally bleak. It was recently reported that in some hospitals, "more than 1,000 people come for myopic laser surgery every month, while nearly 100 patients have 'rework' surgery at the same time," accounting for about 10 percent of the total number of patients.
The question that arises from this is obvious: although the RK technology that emerged 15 years ago has long been phased out due to its own shortcomings, and has been replaced by safer PRK, LASEK or LASIK, will these technologies follow in the footsteps of RK 15 years from now?
Similar warnings came internationally earlier in the year. On December 15 of last year, the UK's Institute for Clinical Excellence (NICE) published a report titled "Guidance on LASIK surgery for the treatment of refractive error," stating that the evidence is currently too scanty for widespread use to demonstrate the long-term safety of this surgical procedure, and that LASIK should not be used as a matter of routine clinical practice, and should not be included without further research and approval by the National Health Service (NHS).
In the report, NICE also tallied four pieces of clinical data and found that the incidence of post-operative problems related to corneal flaps such as flap dissolution, flap thinning, and flap deviation in position was about 4%, corneal burning sensation was 5%, and corneal tissue hyperplasia was about 2%.
The Sunday Times, which scooped the NICE report before it was published, also cited data from a paper in Ophthalmology by Dr. Peter S. Hersh of the New Jersey Medical School in the U.S., which said that the rate of second surgeries for this type of surgery was 1 in 10, not 1 in 1,000 as many advertisements claim. This report caused a shock worldwide, known as the "British call off excimer laser surgery incident".
The BBC followed up with a report from Bruce Campbell, chairman of NICE's Interventional Medicine Advisory Committee. In his interview, Prof. Campbell said that because vision correction can be addressed in such safe ways as wearing glasses or contact lenses, any treatment that poses a risk to the eye such as LASIK requires special attention.
Professor Campbell also warned that a small number of people had worse vision after undergoing LASIK and that eye specialists were looking at possible long-term side effects of the procedure.
The BBC's report, however, appeared more objective, and it also interviewed a number of clinicians who expressed general disappointment with the NICE report.
The eye surgery community in the U.S. similarly refuted the NICE report.
In 2004, 1.2 million laser eye surgeries were performed in the U.S., compared with 100,000 in the U.K. USAeyes sarcastically said on its Web site that if the rate of postoperative complications was really that high, it would have been the U.S. that would have noticed it first.
New findings?
Domestic media reports have once again raised public questions about excimer laser surgery. Since May 20, reporters have called NICE, the Vision Center at the Queen Victoria Hospital in the United Kingdom, and Dr. Hersh, the author of that paper in the journal Ophthalmology.
On May 26, Sheraz Daya, director of the vision center at the Queen Victoria Hospital in England. Dr. Sheraz Daya responded to questions from this newspaper by e-mail.
Reporter: What is the current clinical use of LASIK in the UK? Is the public accepting of the procedure?
Daya: L ASIK is not as popular in the UK as in other countries for several reasons, one being the conservative tendencies in the nature of the British people and their excessive concern for safety, and the other being that LASIK has not yet been introduced into the NHS (the equivalent of welfare healthcare - Ed.), and the British people are not used to spending their own money on healthcare.
Reporter: Is the long-term safety of this procedure guaranteed?
Daya: As long as the medical procedure is done correctly and the patient has no contraindications, there is no problem.
Reporter: But NICE has issued a warning.
Daya: The N ICE report was very poor and used old data. The inference that there is "little clinical practice in the UK" is incorrect because no new data has been included, and the NICE report does not adequately take into account the level of experience and practice in the UK in this area. I understand that the issue is being reassessed and we believe that the new conclusions should be different.
Reporter: Ophthalmology once published an article saying that the number of patients requiring a second operation was 1 in 10, what is that number at your treatment center?
Daia: The fact that a second treatment or revision is not considered a failure was a previous misconception. For several years, the secondary treatment rate for surgery at our own center was 2 percent, and with the introduction of femtosecond laser corneal laminar knife technology, that has now dropped further to 0.5 percent. Personally, I think it would be a shame if there is still 10 percent (failure rate) now, in 2005, and don't want that to happen in some good medical centers.
Reporter: What are your new thoughts on the technology now?
Daia: The technology is great, it's the technology that represents the way of the future, and the fact that we've been able to use it to change the lives of so many people is truly unforgettable!
Dr. Hersh also dismissed the misconception of 1/10 in his article, "The 10% I'm talking about is the secondary surgery rate, which is often used to achieve better vision results, and less than 1% of complications occur with LASIK now."
NICE, on the other hand, was extremely cautious. In several contacts, Woodward, the public **** relations manager, said that Professor Campbell was very much on the ball and was "looking at your interview questions and will respond later."
Problems remain
The Chinese ophthalmology community also organized a discussion two months ago after the NICE report was published. Zhao Jialiang, chairman of the Chinese Medical Association's branch of ophthalmology, said their main points were published in this year's 5th issue of the journal Popular Medicine and that "there is nothing new to add at this time."
They don't dispute that LASIK is now recognized worldwide as the safest and most effective refractive surgery, but "whether or not the surgery can be successful is closely related to the surgical design, the doctor's technical level, and how good or bad the laser equipment is." China introduced PRK in 1993, followed by LA SIK, the overall level is in line with the world's advanced level, "while some low level and poor conditions of medical institutions are also carrying out excimer laser surgery, through the low price competition, this phenomenon is worrying."
Professor Zhao Jialiang estimated that more than 1 million patients have had this surgery in China in the past two years. He said, in fact, any surgery has risks, excimer laser surgery is the same, and it is just a kind of icing on the cake, it is not necessary to do, patients must be careful when choosing.
In the Tongren Hospital Eye Center Refractive Specialist's preoperative informed consent, it lists 21 possible serious consequences: in the event of serious infection, the need for allogeneic cornea replacement, to the point of seriously affecting visual acuity; the existence of overcorrection, undercorrection and refractive regression may be; pathologic myopia is sometimes impossible to determine preoperatively, there is the possibility of postoperative development of degrees higher than the original degree; any refractive level of patients have the possibility of a second surgery ......
"Although the possibility of surgical complications is very low, we have to tell every patient clearly that excimer laser surgery is also a minimally invasive surgery, which does not allow 100% of patients to achieve the expected results. results." Dr. Zhou Yuehua, deputy director of this specialty, said.
However, the doctor's own technical mastery, the reliability of the equipment and the standardized execution of medical procedures can also make a delicate procedure like LASIK perfect. According to data provided by Zhou Yuehua, Tongren Hospital has achieved more than 95 percent of the expected results in a single operation, and there have been no serious complications since 1993.
"A second surgery does not equal failure because each patient's own condition is different, and some surgeries are inherently designed to be completed in two stages, such as older patients with high myopia." He said.
But there are clearly gaps in safety in some areas. in a four-day period from May 16-19, Tongren Hospital admitted three patients with serious LASIK complications. In their medical records, Zhou Yuehua wrote down the diagnosis of "corneal flap fragmentation" and "corneal flap dissolution", and the reasons for this he was not willing to explain too much, "because in the position of Tongren, it is inconvenient to comment on other hospitals. "
Surgical failures like these are encountered hundreds of times a year at Tongren Hospital. Popular Medicine disclosed that "the success rate in some hospitals is below 70 percent, and the situation is not optimistic." A secret that is no longer a secret in the industry is that some hospitals directly buy second-hand equipment from abroad in order to cut costs
========================
When you are faced with the overwhelming advertisements of hospitals of all sizes, each hospital says that its own equipment is how new and advanced, and how clever the doctors are, it really makes you feel overwhelmed when you are choosing. The first thing you need to do is to get your hands on a new one, and you'll be able to do that.
It is recommended to be sensible and calm in your consumer choices, and to be wary of the loudest fishmongers in the market, which are often stinky fish! Medical advertisements are often watered down and exaggerated!
1. Choose the device to pay attention to the misunderstanding:
Excimer laser treatment of myopia common misunderstanding:
A. Laser instrument in the end how many generations is the best?
Answer: There is no uniform "generation" in the world to mark the advancement of lasers! Do not blindly believe the advertisements and media publicity! Because there are one or two dozen manufacturers of excimer lasers in the world, each manufacturer has its own generation, only the first generation of the same manufacturer is comparable.
B. Is it true that the smaller the spot of the excimer laser, the better?
A: No. The spot is too small! The spot is too small, and when emitted at a certain frequency, it can interfere with the procedure by lengthening the duration of the procedure.
C. Is the newer the laser the better?
A: No, technology updates, especially medical updates often need time to verify the 5 to 10 years, the new machine needs to be familiar with the doctor to adapt, just like a new car to have a break-in period.
D. How do I know if a device is good or bad?
A. Data is the most persuasive!
The world's major excimer laser devices :
Wavelength Energy Scanning Time
Germany Imbert 193nm 120-180 gauss 6 sec Patent
Germany Iris 193 134 fiducials 22 sec
America Visions 193 140 fiducials 25
America Hawk Vision 193 130 fiducials 18
Nidec 193 130-150 rotating 30
(Others omitted)
From the above table, it can be seen that the data of various lasers are basically the same, but the operation time is different! Since the shorter the time, the less time the cornea is exposed, the less drying there is, the better the surgery is, the better the patient cooperates on the operating table,
E. Follow the advertisement!
2. choose hospitals rather than choose doctors: as the saying goes: "the mountain is not high, there is God is spiritual, water is not deep, there is a dragon is famous", "worship Buddha to worship Buddha", and not blindly worship "big temple! The reason for this is that sometimes "small temples have small gods". Because sometimes "small temple God is big", but some "big temple God is small", rather than worshipping the "big temple" rather than seeking "real God "The first thing I'd like to say is that I don't want to be a part of it.
In addition, the qualifications of the surgeon should not only depend on the degree, but also on the actual clinical experience of the surgeon in the field of myopia. How many cases of myopic laser surgery experience? How many years of myopic laser surgery history? Does the surgeon have enough experience? Is there a record of failure? What are the results for those who have had myopic surgery?
You can interview the surgeon directly or get a sidebar.
3. Whether the surgery is covered by insurance
In addition, the qualifications of the surgeon should not only be based on the degree, but also on the actual clinical experience of the surgeon, and the position the surgeon holds in the field of myopia. The actual doctor's experience in the field of myopia has been a major factor in the development of myopia," said Mr. Kennedy. "not as good as seeking" real God "because sometimes" temple "small" God "big, sometimes" temple The reason is that sometimes the "temple" is small and sometimes the "temple" is big and sometimes the "temple" is small, so it is better to seek the true God rather than to worship the big temple.
★Komatsu blog original finishing. Reprinted with permission ★
The principle of laser myopia surgery is to use excimer laser, under computer control, to repair the corneal tissue on the surface of the black eye, so that it is smooth, regular, and curved just enough to achieve the position of the light focusing on the macula at the bottom of the eye. If it is not made smooth and regular enough, astigmatism manifests itself, and if the curvature is not in place, postoperative myopia undercorrection or overcorrection occurs. Whether the surgical efficacy is satisfactory is also affected by: 1. equipment and engineers debugging good or bad. 2. physician skill level. 3. patient cooperation and biological response to these three important factors.
There are currently two types of laser myopia surgery. One is called laser keratomileusis (PRK), where the laser repairs from the corneal surface. It is only suitable for myopia below 6.00D, too high a myopia to do PRK, prone to corneal scarring turbidity. The other procedure is called laser corneal interlaminar mosaic (Lasik), which uses a special knife to split the corneal interlaminar layers to make a corneal flap, and laser repairs are made within the corneal stroma; it is suitable for both high and low myopia, and the procedure is more difficult, and prone to complications with the flap. My two daughters and have done laser myopia surgery, the effect is good, but ask them how they feel, the sister said "no regrets". But my sister said: "how not regret, I will not do it again even if I die," indicating that laser myopia surgery has both advantages and disadvantages!
Benefits: 1, is currently the most safe and reliable treatment of myopia, both domestic and foreign reports, or our own experiments, for myopic patients with 6.00D or less, long-term stability of postoperative naked eye vision, 92% ≥ 0.5, 70% ≥ 1.0. For more than 6.00D high myopia, the higher the myopia, the worse the long-term effect of surgery.
2. Compared with the charges for the same equipment and technology in the advanced countries of the U.S., Germany, and Japan, the domestic surgical charges are very low, only as low as those in the above countries ?
3, the domestic physicians have rich clinical experience, preliminary estimates, the number of surgical cases has been more than 300,000 people. Because of the high technology and low price, it has attracted many foreigners to come to China for surgery.
4, fast. Laser irradiation takes only a few seconds and does not require hospitalization.
Drawbacks: 1, surgical efficacy is not perfect, there are always a small number of surgical patients with complications, individual patients and even infections, eye perforation and other serious complications, resulting in a loss of corrected vision or even blindness, due to the laser surgery is carried out in the healthy eye, the eye could have been equipped with corrective glasses vision can be fully restored, if the surgery led to a loss of vision, then the loss is more than worth it. From this point of view, patients undergoing surgery are risky. Both the surgeon and the patient should think twice before making up their minds about surgery.
2, the current laser myopia surgery in our country seems to carry out some of the abuse, a few units with commercial operation, advertising overstatement, not in the technical level of effort, increasing the possibility of complications.
3, excimer laser equipment and technology is still evolving, a few units can not keep up with its development, resulting in patients suffering undue losses.