Teenagers' myopia mostly belongs to "pseudomyopia". A kind of functional myopia caused by overuse of eyes and neuromodulation. If spasmolysis is not corrected in time, it will develop into true myopia after a long time.
Precautionary measures: children must be cultivated with good hygiene habits from an early age.
1. Cultivate their correct writing and reading posture, and don't lie prone on the table or twist their bodies. Books and eyes should be square. The desks and chairs in the school should fit the students' figure.
2. Reading time should not be too long.
3, writing and reading should have proper light, and the light is best irradiated from the left side. Don't read and write in dim light, which can reduce the burden on students, ensure the break time of 10 minutes between classes and reduce visual fatigue.
4. Actively carry out physical exercise to ensure that students have one hour of physical activity time every day.
5, teach students to write, not too small and too dense, not oblique, cursive. Don't take too long to write.
6. Do eye exercises seriously.
7. When watching TV, pay attention to the height of the TV set and the line of sight level; The distance between the eyes and the screen should not be less than 5 times the diagonal length of the screen; When watching TV, turn on small lights indoors, which is beneficial to protect your eyesight; After watching TV 1 ~ 1.5 hours continuously, you should take a short rest, shout to the distance and do eye exercises;
8. Eat more foods rich in vitamin A, various vegetables, animal livers and egg yolks.
Prevention and treatment of myopia should be graded, and early attention should be paid to small ones. Actively correct and prevent further development. If myopia has occurred, you should go to the hospital for optometry and wear appropriate glasses. Pseudomyopia can be corrected by far fog vision, massage or crystal exercises, physical therapy, drugs and other methods.
Playing badminton and table tennis can prevent myopia. In the process of playing badminton and table tennis, the eyes must quickly follow the flexible "small ball movement" trajectory changes, which has unexpected benefits for children aged 5-9.
Second, seven methods of eye care
1, avoid "staring" and pay attention to frequent and complete blinking. Frequent blinking can reduce the exposure time of eyeball to air and avoid tears evaporation.
2. Don't blow the air conditioner for too long, avoid airflow blowing on the seat, and place tea leaves near the seat to increase the surrounding humidity.
3. Eat more fruits, especially citrus fruits, and eat more green vegetables, grains, fish and eggs. Drinking more water also helps to relieve dry eye.
4. Maintain good living habits, get enough sleep and don't stay up late.
5. Avoid operating the computer continuously for a long time, and pay attention to rest in the middle. Usually continuous operation 1 hour, rest for 5- 10 minutes. You can look at the distance or do eye exercises during the break.
6. Maintain a good working posture. Keeping a proper posture and letting your eyes look down at the fluorescent screen can relax the neck muscles and minimize the area of the eyeball exposed to the air.
7. Adjust the screen distance position. It is suggested that the distance is 50-70cm, and the fluorescent screen is slightly lower than the eye horizontal position of 10-20cm, showing a downward viewing angle of 15-20 degrees. Because angle and distance can reduce the demand for refraction and reduce the probability of eyeball fatigue.
If there are few tears and dry eyes, it is not suitable to use contact lenses in front of the computer. Wear rimmed glasses. People who wear contact lenses in front of computers should also use varieties with high oxygen permeability.
People over 40, it is best to use bifocal lenses, or wear glasses with low degree when typing.
If you have redness, burns or foreign body sensation, heavy eyelids, blurred vision, or even eye pain or headache, you need to go to the hospital after rest.
Third, excimer therapy for myopia
It is estimated that there are at least 654.38 billion myopia patients in the world, and myopia research has a history of hundreds of years. In recent years, the most controversial treatment for myopia is corneal laser surgery. The British "Sunday Times" reported that "the government's medical supervision department is preventing the national medical service system from performing eye laser surgery because of concerns about the long-term safety of patients". The American Journal of Ophthalmology also pointed out that "the failure rate of this kind of ophthalmic surgery is110, not11000 as stated in most advertisements." Surgery may also cause complications, so patients must undergo corneal transplantation.
These news also caused an uproar in China, which triggered a hot discussion about "the safety of ophthalmic laser surgery". People who have complications after laser surgery have come out to talk about it, and some media have reported that "myopia surgery, which was popular 0/5 years ago, left sequelae due to limited technical level, and now it has been reworked". Some medical workers came out to refute the British research department's statement and explain the safety of the operation to patients. So, what is myopia laser surgery? What is its success rate and safety? What is the long-term effect? Should I do this operation or not? Welcome to discuss.
Excimer laser surgery has many methods.
The full name of what people generally call "excimer laser surgery" should be "excimer laser refractive corneal surgery", which mainly includes three types of surgery:
(1) excimer laser keratectomy (PRK) is the earliest clinical method. At present, PRK is considered as a safe and effective method to treat moderate and low myopia, hyperopia and astigmatism, but it is rarely used because of its postoperative pain, refractive regression and other complications.
(2) excimer laser in situ keratomileusis (LASIK), which is the mainstream surgery at present. It cuts the stromal layer under the corneal flap, maintains the integrity of corneal epithelium and anterior elastic layer, and avoids most complications of PRK. It is characterized by broadening the correction range of myopia, no pain during and after operation, rapid recovery of vision and no macular degeneration on the cornea. During the operation, a thin corneal flap with pedicle was cut out on the cornea with a micro-knife, the flap was opened, laser cutting was carried out under the flap, and then the flap was restored to its original position. This can be used for low, medium and high myopia. LASIK also has defects caused by corneal flap, such as corneal flap wrinkling, displacement, epithelial implantation under corneal flap, astigmatism and excessive cutting, which leads to corneal dilatation and keratoconus. The use of LASIK is also limited for relatively myopic patients with high and thin cornea, but it is better to choose LASIK for patients with high myopia with thick corneal flap.
(3) Laser in situ keratomileusis (LASEK) is an improved operation of PRK. The corneal epithelial flap was made by soaking the corneal operation area with laser or low concentration alcohol, and the tissue under the epithelial flap was cut by laser. When the corneal epithelial flap is reset, it is still necessary to cover its surface with a layer of contact lenses. After LASEK, the pain is obviously relieved compared with PRK, and the flap is thin, which can be used for patients with relatively thin cornea and large pupil.
As a corneal flap, LASEK has no complications of LASIK, which shortens the healing time of corneal epithelium after PRK and reduces the degree of pain reaction and corneal opacity. However, the corneal epithelial flap injury and edema during operation are the same as PRK, and the speed of visual recovery and refractive stability after operation is slower than LASIK. Therefore, it is mainly suitable for patients with thin cornea, occupational characteristics prone to eye trauma leading to corneal flap displacement or other patients who are not suitable for LASIK surgery.
In addition, not long ago, Ioanes, a Greek physician, took the lead in proposing Epi-LASIK surgery. Epi-LASIK can combine the advantages of LASEK and LASIK and avoid their disadvantages. It uses a rotating epithelial knife to "make a movable epithelial flap" on the corneal epithelial layer, with a thickness of only more than 50 μ m, instead of soaking it in alcohol like LASEK. At the same time, the corneal thickness can be preserved to the greatest extent, and the postoperative irritation symptoms are also very small, the probability of corneal opacity is less than PRK, and myopia subsides.
Fourth, the method of correcting myopia
1. lens correction: including frame glasses and contact lenses;
2. Corneal refractive surgery: radial keratotomy (RK), excimer laser keratectomy (PRK), excimer laser in situ keratomileusis (LASIK), etc.
3. Intraocular refractive surgery: clear lens extraction and intraocular lens implantation in phakic eyes.
It should be pointed out that, considering the factors of safety, simplicity, economy and practicality, ophthalmology believes that for most people, the first choice to correct myopia is to wear glasses. If the patient is going to choose excimer laser surgery, the most concerned issue is the safety of the surgery.
Objectively speaking, the current excimer laser surgery is relatively safe. Compared with the earliest radial keratotomy with diamond knife to treat myopia, its safety has made a qualitative leap, which has been fully proved by a large number of clinical practices in 10 years. It can be said that laser surgery for myopia has been relatively mature in China. However, the success rate of any operation cannot be 100%. Just as contact lenses are easy to be infected and harmful to vision, trauma caused by broken lenses of frame glasses is also one of the causes of blindness. According to the article in American Journal of Ophthalmology, the failure rate of this kind of ophthalmic surgery is110, and most domestic refractive surgery experts hold different opinions. Of course, good surgical equipment, skilled operation and rich experience of operators and good cooperation of patients are the basis of high safety of surgery.
Any operation is risky, and myopia laser surgery can't completely avoid complications. The most common complication is overcorrection or undercorrection, which should be observed for a certain period of time and re-operated as appropriate; Some people may have glare, that is, a light spot is regarded as a light cluster or halo at night, and there is a slight edema reaction between corneal tissues after operation or a large pupil at night, and its edge is close to the surgical edge, which can be gradually reduced. Keratoconus appears in people who have this potential or whose cornea is too thin after operation; Because of poor gaze on the target, eccentric cutting may occur, or the central island may appear due to the action of water vapor vortex on the corneal surface; After PRK and LASEK surgery, corneal Haze and hormonal ocular hypertension may occur due to long-term use of anti-Haze drugs. LASIK has complications related to corneal flap, such as foreign body under the flap, corneal flap displacement and dissolution, increased astigmatism, dry eye and so on. The most serious is the infection of corneal wound during operation. Although it rarely happens, it is the direct cause of blindness, so strict surgical disinfection system and good hygiene habits of patients are very important. After operation, you should also check your eyes regularly, paying special attention to the changes in macular area and peripheral retina, so as to plan ahead.