LASIK is the most popular laser eye surgery. It is performed today in about 50 countries. About 1 million LASIK surgeries are performed worldwide each year. In some countries, such as Japan and the United States, this procedure is even available in shopping malls. The popularity of LASIK is due to its safety and effectiveness.
LASIK is the abbreviation for Laser Assisted In Situ Keratomileusis, a laser surgical procedure proposed by the Greek ophthalmologist Ioannis Pallikaris in 1990.
What is LASIK surgery?
Not to say that LASIK is the newest technique developed in recent years. This method of eyesight defect correction was created back in the 1980s in the USA. The first LASIK surgery was successfully carried out in 1987. Today it is more in demand since it is accessible to almost everyone. LASIK is an acronym. The full name of the procedure is Laser Assisted in Situ Keratomileusis, or simply laser keratomileusis.
This method of vision restoration is performed using a special excimer laser, which is capable of creating strong ultraviolet radiation that affects the cornea and corrects its shape. The procedure is very simple, does not require long preparations, and helps cure almost any visual pathology.
Laser vision correction is a combination of microsurgery and excimer laser treatment, carried out one after the other.
First the microsurgical stage is performed, during which the refractive surgeon uses a microkeratome to form a surface corneal flap in the form of a “valve” about 8 mm in diameter, of equal thickness over its entire area, while maintaining the “stem” fixation to the cornea, and turns it aside, which allows the middle corneal layers to be laser treated afterwards.
The procedure is completely painless and takes about 5 seconds. Keeping the flap’s point of attachment to the cornea allows it to be put back in place at the end of the laser phase.
Laser (refractive) stage is the actual laser correction, the main purpose of which is to model a new shape of the cornea by modifying its refractive characteristics.
At this stage of surgery the excimer laser evaporates corneal areas according to a standard algorithm, whereas in Super Lasik the new corneal profile is simulated according to a personalized program that takes into account individual characteristics of a given patient.
After corneal profile remodeling the corneal flap formed at the first stage is returned in place and is fixed independently without sutures due to adhesive properties of corneal collagen.
The surgery is performed under local anesthesia with pinpoint accuracy and dosed effect of excimer laser. Due to the “cap” forming technology the post-surgery period is quite short, the patient’s vision is restored within a couple of hours after the surgery as a rule.
Corneal tissue ablation performed in its middle layers without damaging the superficial epithelial layer determines the absence of discomfort sensations such as “foreign body in the eye”, “sand”, and excessive tears, and photophobia in the early rehabilitation period and corneal opacity in the late period.
Lasik surgery can be performed for all refractive errors, including hyperopia and astigmatism which are not resistant to PRK method laser correction, as well as for high degree myopia provided that corneal thickness is sufficient.
But the undoubted advantage of Lasik is a strict personalization of laser treatment. In patients with myopia Lasik makes the cornea flatter, in hyperopia the excimer laser makes the cornea steeper, and in astigmatism it ensures the correct spherical shape of the cornea.
Main indications for LASIK procedure
Laser LASIK eye surgery is indicated for the following vision pathologies
- Astigmatism (+/-1 to +/-4), in which a person sees an image blurred and therefore constantly squints;
- Farsightedness/hypermetropia (+1 to +6dptr), which causes low vision at close range;
- nearsightedness / myopia (-1 to -13 dptr) is the most common refractive defect in which a person has poor far distance vision.
People usually agree to laser correction due to intolerance of glasses and contact lenses or lack of desire or possibility to wear them. For example, it is hard to imagine wearing glasses as a lifeguard or for example, a sportsman. Laser correction becomes a great opportunity for many people to do what they like in spite of their eyesight problems. LASIK surgery makes it possible to get rid of glasses and lenses forever or for years to come.
Are there any restrictions to LASIK surgery?
LASIK surgery is very safe and painless. However, it is not available to everyone. There are a number of restrictions that prevent the doctor from prescribing this procedure. The list of contraindications includes relative (temporary) limitations and categorical prohibitions. Temporary contraindications are restrictions that can be lifted by the doctor. These include:
- chronic infection of the eyelids and organs of vision;
- Mild to moderate degrees of “dry eye” syndrome;
- Enophthalmus (excessive retraction of the eyeball into the cavity of the eye cavity);
- lagophthalmus in a pronounced form, when eyelid incontinence is visible to the naked eye;
- diseases of the cornea, which greatly reduce its sensitivity;
- viral keratitis;
- retinal detachment surgery;
- congenital cataract;
- Subcompensated glaucoma or grade 3 glaucoma, in which the eye pressure remains elevated and fluctuates during the day against the background of treatment
- Small size of the eyeball;
- a corneal diameter of less than 10 mm (the norm for an adult is 10-12 mm)
- The optical power of the cornea is less than 39 or more than 49 Dptr (the norm is 43,05 Dptr);
- corneal dystrophy;
- Very thin cornea (thickness less than 400-450 microns);
- Severe deterioration of vision in the last few months;
- exacerbation of autoimmune disease;
- Diabetes mellitus without complications in the form of diabetic retinopathy;
- hormone-dependent diseases;
- minors;
- Pregnancy and breastfeeding.
The list of contraindications is quite extensive, but the listed diseases and conditions are not that common, besides, these are not absolute restrictions. Your doctor may decide to prescribe LASIK or postpone it for a certain period of time, e.g. while treating an infectious eye disease.
When is LASIK correction strictly prohibited?
Absolute contraindications to laser keratomileusis include:
- Severe corneal dystrophy;
- Grade 4 glaucoma in which the intraocular pressure is not reduced by medication;
- immunodeficiency diseases (AIDS, systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis), in which the body’s ability to heal is very low;
- Keratoconus – thinning of the cornea which becomes cone-shaped (if LASIK is used for this pathology, a corneal transplant may be necessary later on);
- Absence of one eye;
- progressive acute cataract;
- Non-surgical retinal detachment;
- Severe diabetic retinopathy;
- Severe “dry eye” syndrome;
- irreversible blindness.
How does LASIK surgery work?
The specific character of the procedure is largely responsible for all the listed contraindications. It is important to follow your doctor’s instructions before and after laser correction of vision. This allows to avoid complications.
Before LASIK is prescribed, the patient undergoes examination. He is examined by an ophthalmologist using high-tech equipment. The ophthalmologist calculates all the parameters of the organs of vision and determines whether correction is possible. Testing for HIV and hepatitis may also be required.
In the 14 days before vision correction, the patient stops using optics. Glasses and contact lenses slightly change the shape of the cornea, and it should take its natural shape. On the day of surgery it is forbidden to wear makeup. The doctor is sure to remind the patient of this. Particles of cosmetics can get on the operated area of the eye and cause infection or irritation. You should not drink alcohol before laser correction of eyesight. It has an adverse effect on the condition of blood vessels and body in general.
How the Lasik Method Works
Injection of local anesthetic drops
Laser correction does not require general anesthesia, a special ophthalmic anesthesia is used so patients feel no pain. In the preoperative room, a drug is dripped, which takes about 15 minutes to take effect.
Preparation for surgery
The patient puts on a protective disposable gown and cap, then lies down on the couch. The surgeon explains how the surgery will proceed and how the patient should behave.
Fixation of the eyelid with a special dilator
Some patients say that this is the most unpleasant moment of the entire surgery, but it is necessary in order to avoid reflexive blinking. The patient is instructed to look straight ahead at the luminous point.
Formation of the flap with the microkeratome
A flap (“cap”) is formed from the surface layer of the cornea with a special device, which is pushed aside so that the excimer laser can affect the deeper layers of the cornea.
Laser exposure
The most important and crucial stage of vision correction. The time of laser influence on the eye is only about 30 seconds, but during this time the shape of the cornea is changed so that the person is able to see clearly with their own eyes again.
Completion of the surgery
After the laser action is over the previously formed “flap” is closed and fixed on the eye by adhesion – sutures are not applied. Therefore, it is very important not to rub or touch the eye during the first post-surgery period to avoid shifting the flap.
Stages of LASIK procedure in details
The procedure is carried out according to the following algorithm. The patient is first inundated with drops containing local anesthetic effect. The medication takes about 15 minutes to take effect. During this time, the doctor will explain how the surgery will proceed. After 15 minutes the patient sits in the chair and an eyelid dilator is inserted into the eye to prevent blinking as a reflex. The patient must look straight ahead at the luminous point during the vision correction.
The surgeon then uses a microkeratome or femtosecond laser (depending on the type of LASIK surgery) to form a corneal flap from the surface cornea layer. It has a diameter of approximately 8 mm. This is the reason why the corneal diameter should not be less than 10 mm. The flap is moved to the side. This makes it possible to get to the deeper layers of the cornea.
Then laser vision correction stage starts. The doctor sends the excimer laser to the cornea and begins to vaporize it, correcting it so that it takes the right shape. The correct shape will be if after correction the light rays fall directly on the retina and are displayed on it, creating a clear image.
Laser correction is completed by the return of the flap onto the operated cornea area. No sutures are put in. The corneal flap is fixed on the eye by itself through adhesion (sticking, joining of the two surfaces). The correction of vision takes about 7-10 minutes. After that the surgery is done on the second eye.
During the correction the patient feels no pain or other discomfort. After a couple of hours the doctor examines the patient and then the operated person may leave the clinic. The surgeon will give some recommendations, which must be followed in the post-surgery period, and appoint the day of the next examination. The patient spends no more than three hours in the clinic.
Recovery after LASIK surgery
As soon as the vision is stabilized, the patient goes home. This already takes 1.5 to 2 hours. It is not advisable to drive for a while. It is better to come to the clinic by cab. You will have to come in for an appointment the next day. In the first few hours, the patient may feel the presence of a foreign body in the eyes, pain. Side effects such as increased sensitivity to light, tearing (or, conversely, dry eyes), decreased crepuscular vision, corneal or eyelid swelling are also possible. All of these symptoms are quite predictable and do not need to be frightened. They can usually be treated with eye drops.
Your doctor will give you detailed instructions before you go home. He will tell you what you can and cannot do while your eyes are recovering. You will have to give up sports. Physical exercise in the form of morning exercises will not hurt, but power exercises will have to be excluded. You should also avoid alcohol for two weeks after surgery. Ethyl alcohol interferes with corneal healing. In addition, while intoxicated, you can injure your eye, which will result in displacement of the corneal flap. Such complication is corrected by repeated laser vision correction. In the first days after the correction it is necessary to avoid eye strain. Books and computer use may be postponed for a few days to allow time for rest.
Also in the postoperative period you should not:
- touch your eyes and rub them with your hands (this can cause an infection in the organs of vision);
- Use cosmetics for two weeks;
- Wash your hair in the first three days after LASIK;
- going to the sauna, bathhouse, or swimming pool for the next two weeks;
- to be in the sun without sunglasses.
The doctor may impose other restrictions as well. Compliance with the ophthalmologist’s instructions is the key to a speedy recovery.
How will I feel immediately after the surgery?
The surgery itself is absolutely painless thanks to local droplet anesthesia. The patient can only feel a light touch on the eye during the preparation for the surgery, which lasts only a few minutes.
Most importantly, the patient begins to see clearly IMMEDIATELY after the surgery. In the first few hours after lasik surgery the eye is swollen due to the formation of the flap. The patient feels this as a slight fog, which passes almost completely within the first 2 hours.
When the anesthesia period is over, you may experience slight discomfort such as feeling ashes, sand, photophobia, or increased lacrimation. Particularly sensitive patients may take a tablet of anesthetic, but in 90% of cases, it will not be necessary.
Some patients do not experience any discomfort at all, it all depends on individual characteristics and sensitivity. In any case, in most cases, all unpleasant sensations disappear after about 2-4 hours.
And after a day, the patient can drive, work at the computer, watch TV (of course, respecting the visual mode) and not experience any discomfort.
What complications can occur after LASIK surgery?
Unfortunately, no procedure or person is completely safe from complications, but LASIK causes complications very rarely. They affect 1-5% of patients. Your doctor will tell you about the possible risks. Complications may include:
- keratitis;
- hypercorrection or hypocorrection (excessive or insufficient evaporation of the cornea);
- ingrowth of the epithelium under the flap;
- Displacement of the corneal flap.
These side effects cause visual impairment. In most cases laser correction of vision has to be repeated.
What are the advantages of LASIK surgery?
Considering the abovementioned facts it is clear why the LASIK eye surgery is so much popular. It has the following advantages:
- The surface for healing is very small, therefore the cornea is restored rather quickly;
- absolute painlessness;
- minimal risk of scarring;
- quick restoration of the visual functions;
- predictability of the results and their preservation (the patient gets rid of visual problems for several years or even for the rest of his/her life);
- outpatient treatment.
Disadvantages of the Lasik
Impossibility to use with thin cornea
The average thickness of a healthy person’s cornea is 515 micrometers. Thin cornea thickness is between 481 and 510 micrometers. Thinning of the cornea can be caused by various factors, such as heredity (the most common reason), high myopia, high intraocular pressure and keratoconus, etc.
The patient finds out the thickness of the cornea at the diagnostics, and if it is thin, the surgery can be either postponed (in order to study the condition of the cornea in dynamics) or another method of correction can be prescribed.
Long-term restrictions on injury-prone sports
Doctors recommend to abstain from contact sports (soccer, hockey, basketball etc.) for 1 to 3 years after Lasik technique as there is a big risk of corneal flap displacement when hitting the eye with a ball or a blow, which must be corrected surgically by an ophthalmic surgeon.
Lasik is contraindicated for people practicing professional sports (all kinds of martial arts, boxing, etc.). In such cases doctors prescribe the PRK method.
Answers to related questions from a top-category ophthalmologist about the LASIK procedure
To perform laser correction, it is not enough just a person’s desire. The doctor needs to make sure that the particular patient will not develop any complications after the surgery. Contraindications include corneal dystrophy, inflammatory processes in the anterior eye segment, high degrees of refractive error.
But there are also certain medical indications for which this procedure is indispensable. Without it, life would be at least uncomfortable. For example, anisometropia: when there is a difference of refraction (optical power of the eye) between the two eyes, intolerance of soft contact lenses, professional activity for which spectacle correction and contact lenses are prohibited, and others. Everything is strictly individual.
What is the essence of the surgery?
Excimer laser vision correction is performed through the effect of laser energy on the eye. The laser beam pulsed the cornea, vaporizing tissue in different areas with optimized power by Perfect Pulse Technology, creating a more even surface with a natural aspheric profile. At the same time, the more physiological shape of the cornea of the eye is preserved.
The latest technique is so “smart” and precise that it eliminates problems related to postoperative dusky vision disturbances, provides individual selection of corneal asphericity and allows perfect sizing of optical zones to maximize the opportunities of vision correction.
Exposure to the laser lasts a few seconds
Is surgery performed on both eyes at once or separately?
It is more physiologically sound to perform excimer laser vision correction on both eyes. But there are different cases.
How long does the procedure take?
Only a few seconds! The surgery itself takes up to 5 minutes. This includes time to prepare the patient and check the equipment.
The speed also depends on the person’s behavior at each stage of correction. That is why a detailed consultation is conducted with the patient beforehand and the doctor answers all the questions. After all, the patient needs to understand what is happening to him. In this way unnecessary fears are also removed.
At what age is it possible to undergo surgery?
Excimer laser vision correction for myopia, hyperopia and astigmatism is indicated from 18 to 45 years of age. Laser treatment is not recommended before the age of 18 since it may result in refraction changes due to the growth of the eyeball. At the age over 45 presbyopia develops as a rule – natural vision changes.
But we should not forget that there are other refractive problems. If a follow-up correction is necessary for those patients who have already had surgery and have an implanted artificial lens, but they need to correct the residual refractive error. In such cases, surgery can also be performed in other age groups, if indicated.
Can all patients see again at 20/20 after Lasik procedure?
If before the surgery with the maximum optical correction the patient could see 20/20, after it he/she gets the 20/20 vision as planned.
Is the procedure painful? Is anesthesia administered?
Laser surgery is painless with the help of special drops. That is why the patient feels quite comfortable. General anesthesia is not indicated for excimer laser correction.
Is the correction safe?
Yes, of course it is. Each laser pulse is monitored during treatment. The influence of environmental factors (such as humidity and temperature) on the surgery is also excluded. The optical system is completely isolated. It protects the eyeball from thermal shock, which speeds up and facilitates the recovery process.
The integrated automatic eye tracking function, the safe high ablation speed and the fixation test also play an important role, all of which prevents even the possibility of eye injury.
Can complications occur immediately after surgery?
If a patient observes all the conditions of correct behavior in the early postoperative period and regularly performs instillations of anti-inflammatory drugs the development of complications is absolutely excluded.
How does the recovery process go?
In “one day” mode. There is no need for hospitalization. The patient spends in the center only 2-3 hours. And this includes pre-operative preparation and obligatory post-operative examination. Then the patient returns home. Immediately after the surgery the patient could be disturbed by pain in the eyes which passes within 2-3 hours or by the next morning.
Can the vision gradually get worse after the surgery?
The post-operative result doesn’t change with the time. This fact has been confirmed by years of observations. However, it must be kept in mind that deterioration of eyesight is possible in case of age-related changes in the organism after 45-50 years.
Good eye hygiene and a healthy lifestyle will allow the eyes to be in “good shape” all the time.
Can the surgery be repeated and is it necessary?
Sometimes in especially complicated cases extra correction is necessary and there are technical possibilities. The doctor informs the patient about the necessity of the procedure beforehand. But most often there is no need and the correction is done in one step.
Can I lead an active life after the surgery?
You will have to suffer a little. Immediately after the correction, during the first month, it is important to observe a number of restrictions. They just exclude the possibility of negative impact on the postoperative zone. After a month all the restrictions are lifted and a person can lead a usual life.
Is a certificate of incapacity for work issued after the surgery?
Yes, if necessary for 5 to 6 days.
Can I have the surgery during pregnancy?
This procedure is not recommended during pregnancy.
Is it possible to have an independent delivery after correction of vision or caesarean section will be needed?
Correction has no influence on this question. The mode of delivery (natural or cesarean section) depends not on the laser surgery performed on the cornea, but on the obstetric and gynecological status.
The ophthalmologist evaluates the condition of the retina, the presence of pathological areas that threaten complications in the retinal period, and warns the expectant mother of possible consequences.
If your work is computer-related, will there be any special restrictions after the surgery?
In the first days you should limit your visual load. Then it is necessary to observe visual hygiene and try to take breaks when working with the monitor, as it is useful to remember for every office worker.
Will it be necessary to protect your eyes from the sun?
I would advise all people in general not to forget about sunglasses. After all, they protect the structures of the eye from the harmful effects of the ultraviolet spectrum.
How soon after the correction can I drive?
Within the next days after the surgery if the post-surgery irritation to the environmental factors is eliminated.
Correction does not lead to any restrictions. You can continue to live your life to the fullest, but it will look much clearer and brighter than before.
What time of the year is better for laser correction?
It doesn’t matter what time of the year it is better to have the surgery. The main thing is to avoid colds in the first two weeks after the surgery.
Does it hurt to have a laser correction?
The procedure is practically painless. Local anesthesia (in the form of drops) is applied during the procedure. During the procedure you will only feel the doctor’s touch. For the first 24 hours, you may feel dry and “blotchy”. As a rule, the discomfort is completely gone within the first 24 hours.
How long after laser eye correction surgery is it possible to plan a pregnancy?
A pregnancy can be planned 3 to 6 months after laser correction of vision.
Won’t my vision become worse after the surgery. Can I go blind?
No. If before the surgery the patient had no contraindications for vision correction, and this is determined by careful diagnostics with multiple apparatuses and by the doctor’s examination, then after the surgery the vision is guaranteed to be much better. It is very important to follow all recommendations of specialists. In the history of laser correction there has not been a single case of total loss of eyesight after the surgery.
If there are any minor risks in laser correction we will offer you to refuse it. We dispose of a whole modern arsenal of alternative types of correction and we will discuss those possibilities with you.
Are there any serious complications after the surgery?
We can’t entirely rule out the possibility of complications, but they are not catastrophic. The risk of postoperative infection after laser surgery is very low. According to world data it is 1:30 000. LASIK is a safe and predictable procedure. However, slight under- or overcorrection is possible that may be caused by individual peculiarities of the organism and eliminated by a minor surgery in 3-4 months. With SBK-LASIK, this risk is minimized to about 1%.
