In fact, INTRA LASIK surgery is a vision correction surgery that uses laser to cut the cornea.
It is better for patients with appropriate degrees, the technology is more mature, and there are fewer mistakes. Here I just want to post some of the adverse symptoms of other patients after surgery as a reminder.
Case 1: A person underwent lasic surgery in a provincial hospital in September 2003. The left eye had a myopia of 725 + astigmatism of 50, and the right eye had a myopia of 950 + astigmatism of 100. After the surgery, the right eye My eyes have always had glare and astigmatism (there is a very obvious double image on the lower right side of the object I am looking at), which is particularly obvious when entering a slightly dark environment. I can hardly see any fonts clearly with single vision in my right eye, and it is all blurry. It has no effect regardless of the distance of the viewed object. Moreover, he developed eye fatigue (foreign body sensation in his right eye and periorbital swelling and pain in his right eye) after reading for 5-10 minutes, making it almost impossible to study. After that, I repeatedly went to the Excimer Center for treatment and was told to slowly adapt to it, which was extremely painful. In October 2004, I went to the Excimer Center for consultation again and strongly requested a corneal topography examination. As a result, the topography examination revealed that the right eye was eccentrically cut (toward the nasal side). The surgeon has now admitted that this is indeed the cause of the symptoms in the right eye. And trying optical lens correction is ineffective. Although the topographic map of the left eye is not perfect, it is acceptable. In fact, there is only a slight glare at night, which basically does not affect the vision. The most recent visual acuity chart shows unaided visual acuity: 1.0 for the left eye and 0.8 for the right eye, and I feel that the astigmatism in the right eye is getting worse and worse, and the visual quality is extremely poor. I used to have fatigue and pain in my right eye when reading. Recently, I don’t do close study. I just wake up and open my eyes. When I opened my eyes to look at things, I felt unbearable swelling and pain around my right eye. The intraocular pressure was normal. CI was performed not long ago, and there was no space occupying the retrobulbar and other parts. I heard that the latest wavefront phase difference technology such as TOP LASIC can solve the astigmatism and glare caused by off-center cutting...
Case 2: Someone did it on January 16, 2004 LASIC is currently 1.2 in the left eye and less than 0.8 in the right eye (can be corrected to 1.5 and 1.2 respectively before surgery, both eyes have 550 degrees plus 50 degrees astigmatism). The most painful thing now is that the eyes are often foggy. There is always a sense of gauze, especially in places where there is smoke. It seems that my right eye cannot be corrected with glasses. It only gets better in the afternoon.
Attachment: Lasik surgery related
First, the psychological aspect: First of all, you should have your own requirements to take off your glasses, and it is best to seek the opinions of your family. Secondly, you should not be too demanding about the results of the surgery. In daily life, a vision of 0.5-0.9 can be achieved without wearing glasses. Therefore, the International Health Organization (WHO) lists this vision level as the standard for basic removal of glasses after surgery. After the operation, the visual acuity was 1.0, reaching the standard of complete removal of glasses. Of course, some patients achieve better results, and the degree of recovery after surgery varies from person to person. second. Physical aspect: After you decide to undergo surgery, a comprehensive vision examination can determine whether you can undergo surgery.
Preoperative Precautions
1. Do not wear hard contact lenses within 3 weeks before surgery, and do not wear soft contact lenses within 2 weeks before surgery.
2. Within 3 days before surgery, please follow the doctor’s advice and use antibiotic eye drops every day (such as chloramphenicol eye drops, gentamicin eye drops, or Tailibital eye drops); without the doctor’s permission, Do not use other medicines on your own.
3. The correct use of eye drops after surgery is very important for the recovery and stability of vision, so I hope you will pay attention to it. Please start practicing the correct method of eye drops 3 days before surgery:
Wash your hands, lie down or sit on your back, tilt your head back, open your eyes, and use the index finger of one hand to gently fix the lower eyelid at the lower edge of the orbit. (Do not compress the eyeball.) Hold the eyedrop bottle with the other hand about 3cm from the eye and drop 1-2 drops of eyedrops vertically downward into the lower fornix. Release the lower eyelid, close your eyes and rest for 2 minutes. Note:
(1) When instilling eye drops, the solution should not be dropped directly on the cornea. Do not close your eyes forcefully to prevent the solution from spilling, and do not let the mouth of the bottle touch the eyelids, eyelashes or other objects. , to avoid contamination.
(2) If the doctor instructs you to instill more than two kinds of eye drops, different eye drops should be instilled alternately, with an interval of 10 minutes between each time. The eye drops should be shaken well before each use.
4. Please do not use any cosmetics or perfume within three days before surgery.
5. Eat digestible food appropriately before surgery, and do not eat on an empty stomach or overeating.
6. When coming for surgery, please prepare the surgery fee, re-examination fee and round-trip transportation fee, and pay attention to safety. Please bring your ID card or relevant documents with you so that you can verify your name during the surgery to avoid mistakes.
7. Please wash your hair, take a bath, cut your nails and maintain good personal hygiene one day before the operation.
8. If you catch a cold or have any special physical discomfort before surgery, please inform the doctor so that we can handle it as appropriate. Female friends, please try to avoid undergoing surgery during the menstrual period.
9. Please arrange for a relative or friend to accompany you to the operation and escort you home after the operation. Please do not bring children with you.
10. In order to allow the eyes to recover well after surgery, it is not advisable to undergo surgery when you are busy at work. Please discuss the surgery date with your doctor based on your specific work and life circumstances. Please come on time for preoperative preparation and surgery according to the scheduled surgery time.
If you need to change the operation time for special reasons, please call us in advance so that we can make corresponding adjustments.
11. We will prepare all the medicines, supplies and written medical instructions required for the postoperative recovery period for you in advance. Please rest assured and hope that you can come to the operation comfortably and happily
What tests should be done before LASIK surgery?
In order to understand the eye condition, eliminate contraindications to surgery, and determine the diopter that should be corrected during surgery, a detailed examination is usually performed before surgery to understand the corneal thickness, diameter, curvature, diopter, eyeball axial length and eyeball diameter. pressure, etc., mainly including the following contents:
⑴ Far and near vision (naked eye). ?⑵ Routine slit lamp microscopy to understand the condition of the cornea, anterior chamber, pupil and lens. ?⑶ Fundus examination: observe the condition of the optic papilla, retinal blood vessels, macula and retina. ?⑷ Combine strip photoretinoscopy, computer refraction and insert subjective refraction. If necessary, mydriatic refraction is also required to correct the refraction to the best state. ⑸ Corneal topography examination: You can understand the membrane curvature, diopter, etc. to rule out keratoconus. ?⑹ Measurement of intraocular pressure to exclude low intraocular pressure and glaucoma. ?⑺ Ultrasonic detection of the length of the axial length of the eye and the thickness of the cornea. Since the surgery is mainly performed on the cornea, corneal thickness is one of the important data for the surgery. ?⑻ Internal medicine excludes autoimmune diseases and connective tissue diseases.
After the above-mentioned steps of examination, we have obtained first-hand information about the operation. After further ruling out the contraindications to the operation and understanding the possible situations after the operation, we can sign the operation consent form. Had surgery.
Preoperative examination content
When you decide to undergo laser surgery for myopia, you must have a comprehensive and systematic eye examination, including:
Vision examination: Including naked eye visual acuity and best corrected visual acuity with glasses.
Refraction examination: including computer refraction, dilated refraction and re-examination. Whether the refraction is correct or not directly affects the surgical effect.
Anterior segment and fundus examination: focus on checking the transparency of the cornea, whether there are scars on the cornea, whether the lens is opaque, and the fundus examination whether there is vitreous opacity, fundus lesions, etc.
Intraocular pressure examination: to rule out the possibility of high intraocular pressure and glaucoma.
Keratometric examination: exclude the possibility of keratoconus and flat cornea.
Corneal pachymetry: For patients whose central corneal thickness is less than 500, if the patient is highly myopic, attention should be paid to the depth of corneal center cutting, and the relevant situation should be explained to the patient before surgery.
Coreal topography examination: The main purpose is to understand the regularity and symmetry of the entire corneal surface, excluding various abnormal factors.
Wavefront aberration inspection: In addition to low-order aberrations such as myopia, hyperopia, astigmatism, etc., the eyes are checked to see whether there are high-order aberrations that seriously affect the visual quality, and high-order aberration data are collected as The basis for diagnosis and surgery is to remove high-order aberrations during surgery.
After a basic examination, the doctor can tell you whether you are suitable for LASIK surgery.
Excimer laser in situ keratomileusis (LASZK) is currently one of the main methods for the clinical treatment of refractive errors in ophthalmology. Because of its advantages of obvious curative effect, large amount of correction, early stabilization of refraction, no obvious discomfort symptoms and low myopia regression rate, it has been accepted by more and more myopia patients. Since our hospital started operations in May 1998, it has performed LASIK surgeries on 4,553 patients and achieved remarkable results. The following is an introduction to pre- and post-operative care.
1 Materials and methods
1.1 General information There were 4553 patients in this group, including 2500 males and 2053 females, with 9027 eyes, aged 18 to 48 years old. Preoperative refraction was -6.00～-23.00D. The average naked eye visual acuity was 0.4 and the average corrected visual acuity was 0.8.
1.2 Method: Instill topical anesthetic into the eye twice 5 minutes before the operation. The eyelid opener is used to expose the eye. Use a microkeratome to cut a pedicle with a diameter greater than 7.2 mm and a thickness of 130 to 160 mm in the center of the cornea. The corneal flap has a pedicle located on the nasal side. The flap is opened to expose the corneal membrane stroma, which is cut by an excimer laser. After the operation, Ringer's solution is used to flush the corneal bed and corneal stroma surface, and the corneal flap is reset.
2 Preoperative care
2.1 The patient is selected to be aged 18 to 55 years old, with stable refraction for more than 2 years; stop wearing contact lenses for at least 2 weeks; exclude other eye diseases and Diseases related to various systems of the body, such as autoimmune diseases and diabetes.
2.2 Check naked eye vision before surgery. Mydriasis refraction to determine the diopter and prevent under- and over-correction; slit lamp and fundus examination to rule out high myopia combined with retinal detachment and fundus disease; corneal topography examination to rule out keratoconus; non-contact tonometer to measure intraocular pressure, Exclude pathological glaucoma.
2.3 Preoperative treatment: 48 to 72 hours before the operation, antibiotic eye drops are instilled in the operative eye. Eyelashes are cut off 15 minutes before the operation. The conjunctival sac is rinsed with 3% boric acid solution. During the rinse process, eyeball fixation training and training are performed. Look straight up, turn up and down, then instill topical anesthetic, instruct the eyeballs to relax, and avoid squinting hard to prevent accidents during the operation.
2.4 Most of the patients undergoing LASIK surgery in psychological care are young adults, especially young people aged 18 to 20. Most of them need surgery to improve their eyesight to study, join the army, or find a job. Patients have high expectations and are worried. I am afraid, so I take the initiative and patiently explain it to the patient so that the patient can have a correct understanding of the surgery.
Explain to the patient the sound and burnt smell produced when the cornea is cut during the operation, so that the patient can be aware of it. During the operation, the head is fixed and the eyeballs are fixed. Do not close your eyes and watch the indicator light to avoid affecting the position and accuracy of the cutting and causing off-center or irregular astigmatism.
3 Postoperative care
(1) Rest in bed after surgery, close your eyes lightly, avoid squeezing and collision, wear a hard eye mask before going to bed, and avoid strenuous exercise within 1 week sports. There was 1 case in this group where the hard eyecup was too loose and the eyecup was displaced. After rubbing, the corneal flap folded and was reset on the second day after surgery, which prolonged the healing process. This is very important and patients must pay attention to it.
(2) Keep the head and face clean and hygienic, and be sure to wash your hands before instilling the medicine. It is normal to shed tears due to photophobia and foreign body sensation on the same day. Do not panic and wipe the tears with a clean handkerchief. Antibiotic eye drops were administered 4 times a day for 3 consecutive days. The patient was instructed to avoid swimming and bathing in public baths for 3 months to avoid dirt and foreign matter entering the eyes. He was advised to wear dust-proof goggles when going out when the wind was strong. Once your eyes develop redness, swelling, photophobia, tearing, foreign body sensation, or increased secretions after 3 to 5 days, you should go to the hospital for diagnosis and treatment in time. No infection occurred in this group.
(3) Postoperative medication: Fluometholone eye drops 4 times a day within 2 weeks, 3 times a day within 3 to 4 weeks, 2 times a day within 5 to 6 weeks, 7 to 8 weeks 1 time per day. Provide medication guidance and adjust medication under special circumstances. Instruct the patient to take one drop of medication at a time to avoid steroid-induced glaucoma caused by overdose. For patients with slightly higher intraocular pressure before surgery, they must be cautious when using medication after surgery. Shorten the medication time and reduce the dosage without affecting vision. Once intraocular pressure rises and vision drops significantly, seek medical advice promptly and take medication early. Treat early. In order to stabilize the surgical effect, do not stop the medication without authorization.
(4) Regular follow-up visits must be carried out on the second day after the operation. If there are no special circumstances, follow-up visits are required every week, one month, half a year, one year, and two years. If special circumstances arise, seek medical treatment promptly and deal with them promptly to ensure the effectiveness of the surgery.
(5) Dietary guidance: Instruct patients to eat foods containing vitamin A to facilitate corneal nutrition, promote corneal wound healing, and repair corneal epithelium. Avoid spicy foods, large amounts of seafood, tobacco and alcohol, and other irritants. foods to avoid aggravating the inflammatory response and prolonging the healing process.
Precautions before LASIK surgery
In the past few years, from RK to EXCIMER and the advent of LASIK, ophthalmologists have become more interested and devoted in refractive surgery. Both in terms of quality and quantity, there has been explosive growth. Compared with PRK surgery, the biggest advantage of LASIK surgery is that it does not destroy the basic structure of the corneal epithelium. The disadvantage is that the surgical skills require a period of learning, and the complications caused by corneal flap cutting are about 3%. Unfortunately, if it happens to beginners, , it is easy to cause psychological retreat. The following provides some brief insights into the selection of patients before surgery:
1. Patient screening and surgical consultation
Pre-operative consultation is actually similar in various refractive surgeries. , the patient must be allowed to fully weigh the convenience and harm that the surgery will bring, and the consultation time can be shortened through brochures, web conversations, or videotapes. The patient's age, occupation, and vision requirements are all very important considerations. It is advisable to avoid excessive expectations of the patient. As for whether the consultation process should be authoritative or relaxed, it is a matter of opinion.
Patients often raise questions including the success rate of surgery, whether the degree will return or recover, whether they can no longer wear glasses after surgery, whether the visual acuity can reach 1.0, or how long it will take before they can return to work, and when they can. Issues such as driving at night are well prepared for consultations and discussed with the patient in detail, so that a good preoperative relationship between the patient and the doctor can be established.
In addition, because LASIK surgery involves a series of steps, some potential risks, such as the adsorption ring cannot absorb the eyeball, the cutting knife cannot complete the cutting and other complications. Although the incidence rate is very low, it may be possible to deal with some special risks. The patient has a brief discussion to avoid causing trouble to both the doctor and the patient during the operation. In the event of a valve complication, it is advisable to calmly allow the corneal flap to be reset before explaining. Do not discuss loudly before the end of the operation, which may increase the patient's fear. It is best to include the above consultation in the surgical consent form.
2. Preoperative examination (patient screening)
A complete preoperative examination for LASIK should include:
1. Orbital structure
The structure of the eyelids, the size of the eye fissures, and the eyeball itself are all essential factors for whether the surgery can create a good surgical field of view. When the eyelid fat layer is thick, the eyelids are small, and the eyeballs are sunken, Patients should be prepared with screw-fixed eye braces. For patients with extremely narrow eye fissures and extremely deep-set eyeballs, they should also be informed of the possibility of LETCANTHCTOMY or retrobulbar paralysis.
2． Corneal Curvature (KERATOMETRY)
KERATOMETRY only measures the curvature of the central three millimeters of the corneal surface, so it has been replaced by other instruments in showing the true shape of the cornea. However, the K value will still affect the thickness of the corneal flap and The cutting diameter and the curvature of the cornea are too flat (K＜39) or the curvature is too steep (K＞48). It is very likely to form a separated corneal flap (FREE CAP) or corneal hole (BUTTON-HOLE) when using the corneal lamellar knife. .
3. VIDEOKERATOGRAPHY
Preoperative and postoperative corneal topography plays the most important role in refractive surgery. With the help of computers, the corneal surface can be analyzed qualitatively and quantitatively, making it impossible to hide irregular cornea that is not suitable for refractive surgery, thus greatly reducing the risk of surgery.
Currently, the analysis of corneal topography can be divided into two categories, one is placido disc technigue, such as EyeSys corneal analysis system; the other is Elevation-based technigue, such as Orbscan corneal topographic system; the latter is composed of 40 fine slit rays are projected onto the corneal surface, which can simultaneously analyze the front and rear full corneal curvature and full corneal thickness.
The application of corneal topography in clinical practice can be said to be very valuable, especially in the screening of refractive surgery. Here are three corneal diseases that are not suitable for refractive surgery:
A. OCCULT KERATOCONUS
Keratoconus is a disease in which the cornea undergoes local progressive thinning and protrusion. Symptoms usually begin in adolescence, but the clinical symptoms may not be obvious in the early stages. We call it It is (Forme fruste Keratoconus). If you find the following three conditions during the Topography check, you should be highly suspicious of Keratoconus.
In one of the two eyes of the same patient, the local diopter in the lower quadrant of the cornea exceeded 50D.
The difference between the corresponding areas of the two eyes exceeds 3D.
The lower half of the cornea is steeper than the central or upper half, and the difference exceeds 3D. Once the above situation is discovered, it is best not to perform surgery hastily.
B. CORNEAL WARPAGE SYNDROME
Patients who undergo refractive surgery usually wear contact lenses (especially hard contact lenses), which will cause changes in the curvature of the cornea. Common corneal warp syndrome includes: Irregular astigmatism, loss of radial symmetry, and abnormality of the normal corneal central steeple-peripheral flattening decreasing pattern. If there are any of the above abnormalities, it is recommended to wait until the pattern on Topography stabilizes before undergoing refractive surgery.
C. Pellucid Marginal Degeneration
Occasionally occurs in young people. It is a degenerative disease. The cornea in the lower proximal area becomes thinner, resulting in a high degree of astigmatism. The curvature of the central cornea is relatively flatter than the lower cornea. for its characteristics.
4. Pupil size
Including two values ??under dark room and general lighting. Assuming that a young person's pupil diameter is larger than normal, it is best to inform before surgery about the occurrence of glare, halo and driving at night after refractive surgery. Difficulties are more likely. For such patients, unless they are highly myopic, a larger optical zone laser can be designed to overcome them.
5. Refraction (automatic refraction and manual refraction)
Most refractive surgeries use obvious refraction as the indicator, but it must be confirmed again with inserts and appropriate increases or decreases must be made. But to avoid over-correction, it is best to have mydriatic refraction (objective refraction), especially for patients under 40 years old with high myopia, astigmatism and mixed astigmatism. However, the myopia degree after objective refraction can only be used as a reference, and the laser correction degree In the end, the degree of insertion still needs to prevail.
6． Vision examination
Including naked vision at distance and near and best corrected visual acuity, should be recorded in detail.
7. Slit lamp examination
This part should include eye tissue examination, tear layer assessment and intraocular pressure measurement. It is recommended that the tear examination include at least Schrmer’s Test and Tear Break-up Time. If the test results are extremely abnormal, the possibility of collagen disease should be suspected. At this time, it is best to draw blood to confirm. As for patients who are diagnosed with primary dry eye syndrome, it is best to be informed before surgery of the possibility of prolonged use of artificial tears after surgery.
8． Corneal Pachymetry
Ultrasound corneal pachymetry is absolutely necessary for any laminar corneal reshaping surgery.
For patients with very high myopia (greater than -12D) whose central corneal thickness is less than 500 microns, special care must be taken during LASIK surgery. If the cutter can set the thickness of the corneal flap, a thinner corneal flap should be cut. In addition, more Laser correction method in the optical zone is used to reduce the cutting depth of the stromal layer. Of course, it is best to measure the stromal bed thickness during the operation. If after calculation, the multi-optical zone method still cannot make the postoperative stromal bed thickness greater than 250 microns or the overall cornea. If the thickness is greater than 360 microns, the operation should be abandoned.
9. Fundus examination
The retinal macular area and surrounding areas of the fundus should be examined in detail. When retinal holes and grid-like changes are found, the patient needs to be informed that there is a high risk of retinal detachment and should undergo refractive surgery. Preventive treatment before treatment.
10． Dominant eye (sharp eye) examination
When a patient's two eyes need to be operated on for a period of time, it is generally recommended to open the non-dominant eye first as a reference for the dominant eye operation. For some myopic patients who want to retain one eye after surgery, there are two methods, which can be to correct the dominant eye; or to correct the non-positive eye without correction. Usually, a sharp eye inspection can be done quickly using the Holo In Hand method.
3. Excimer operating room condition setting
Although the environmental conditions required by each excimer equipment are slightly different, the basic requirements include dust-free, independent air conditioning, constant temperature (15~25℃), and fixed humidity ( 20%~50%).
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