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Eye Surgery |
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Laser refractive surgery
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Dr. Yoram Shohat |
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Member of the American and European Society of Cataract and Refractive Surgeons.
Ophthalmologist in Israel and member of the Ophthalmologist’s Assoc |
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 There is no surprise that many people would prefer to stop the dependence on glasses or contact lenses by doing the refractive surgery. What is the difference between laser refractive surgery methods?
It happens on the daily basis, either on the way to work or going outside your warm house in the cold it makes your glasses weeping and you can’t see anything because of that. After scrupulous cleaning and polishing, you can see the light again, but now your glasses are in uncomfortable position on your nose, so you have to slip your hand out of your pocket and fix them. Not to mention repairs, routine frame changing, vision tests, scratches, falls, accidents (someone sat down exactly on your new glasses), etc.
Therefore, there is no surprise that many people would prefer to stop this dependence on glasses and/or contact lenses by doing the refractive surgery.
What does it mean to wear glasses or lenses?
To wake up in the morning and to stray in the dark.
To depend on plastic accessories.
To hold a ceremony of lenses cleaning with solution from time to time in the evening / morning.
Do not drop off to sleep near the TV, far be it from me!
To avoid swimming (it’s forbidden to swim with lenses), to avoid jogging (perspiration causes etching), surfing (insolation danger), and even making a trip when the weather is not so fine (all these because of a small grain of sand in …eye).
For whom is eligible the laser refractive surgery? This surgery is eligible for everyone who wears glasses with following restrictions:
- If the glass number is stable during one year at least before the therapy.
- If there is no other eye disease: glaucoma, cataract, cartoconus or other medical problems like diabetes, psoriasis, etc.
- Cornea data (cornea thickness and its structure) must be compliant with acceptable criterions. It is impossible to do laser therapy in thin or distorted corneas.
- Numbers range. It is acceptable to operate between +3.00 (long-sightedness of 3 numbers) to -9.00 (short-sightedness of 9 numbers). When numbers step over the bounds of the above-mentioned, surely don’t do laser, but at the same time, there are other methods for glasses removing, like intraocular lens transplantation.
- The therapy cannot be carried out during the pregnancy period.
What is the difference between laser refractive surgery methods? Generally speaking, laser beam cancels glasses necessity by making corneal polishing (a front transparent part of eye).
Laser beam polishes a cornea and changes in this way cornea’s curvature in order to make it similar to curvature of contact lens that person has to wear for a good vision. Actually, the laser beam cornea polishing is being used in all methods.
There are two basic surgery methods: LASIK method, when we detruncate a thin layer of the cornea (make from eye a thin slice called FLAP), move this slice aside, polish cornea by the laser beam and return the FLAP to its position at the end of the polishing process.
The second method is called PRK and there is no cornea detruncating here. By using this method we gently remove a superficial cells layer that covers a cornea (epital/apical cells), and then we polish it by laser beam.
Is this a painful therapy? And how long it takes? This type of surgery is not painful at all! Your eye will be anesthetized by eye drops (there is no injection or something else “scary”). In therapy types that include cutting, a feeling of light pressure on eyeball may occur for a short period of time, but as already mentioned, there is no pain.
According to the majority of patients, it’s possible to take a tranquilizer tablet before a surgery in order to decrease both a normal stress and a fear before the surgery (you are not obliged to do that, but almost all patients are taking such tablets).
Duration of surgery is a matter of 1-2 minutes for each eye; laser itself lasts less then one minute. If a number is higher, the laser therapy is longer, but as already mentioned, less then a minute. With low numbers the therapy lasts 15-20 seconds only.
What happens if either I’m moving during the surgery, or eye is moving or closed? During the surgery there is no possibility to close an eye, because lids are held by gentle “lid speculum” that prevents closing.
Eye tracker is placed in laser and it’s responsible for laser place changing according to every tiny eye movement (during a fraction of a second); that’s why even if an eye or a patient moves, the laser beam will touch exactly the required place. If a movement is more then 1.5 mm, laser stops automatically and waits till eye returns to its place. During the surgery physician is checking an eye all the time and instructs the patient when required.
What is the risk of an irreversible damage to eyes? As in every surgery there is a possibility for complication, far be it from me. Most of complications don’t cause an irreversible damage, but much of our regret in rare cases such damage may occur. We are talking about one in a few thousands.
Is it possible to treat both eyes together? In the past, it was normal to operate just one eye at a time, however, since then it’s a common practice to operate both eyes together. Statistically, it’s safer to operate both eyes than each of them in order to avoid an additional institute visit for a second surgery, which is more dangerous than both eyes surgery.
Is it necessary to do repeated surgery in future? This is one-time surgery and its results should remain stable for a long period of time. In a small percent of cases, a few may be left after the surgery, and in other rare cases retreat takes place in a time, i.e. reappears with time. In these cases, it’s almost always possible to do the repeated surgery. If the goal was not reached during the initial and repeated surgery, it would mean that this eye doesn’t response as expected and additional surgeries will increase the risk.
When can you feel a vision improvement? Right away after the surgery. There is a recovery period and during this time your vision is not at the top yet. For each person this period is different and depends on surgery technique.
In SURFACE methods, the recovery period is longer then in the methods of cornea detruncating, but there are other advantages of SURFACE method. Generally speaking, patient’s vision becomes good within a week, without reference to surgery method.
Whether the vision is as good as of a man that never wore glasses after the surgery? The goal of surgery is to give a patient an improved vision without any glasses or lenses. To drive, to watch movies, to read, etc.
Any laser surgery cannot guarantee 6:6 vision to everybody. All depends on natural data of your eyes.
Is it possible to do repeated corrections? The number of repeated corrections is unlimited. If health status makes it possible to do correction, the vision stabilizing procedure may be considered only after six months of the surgery.
Are there any common side effects? Very occasionally, temporary night blindness may occur, in other words you can see an areola around lights or wings that start from the light source. This is not a common phenomenon, and in overwhelming majority of cases this phenomenon disappears within 2-3 months. It must be emphasized that most of contact lenses wearers suffer from temporary night blindness.
The most widespread side effect is eye dryness and patients are asked to use eye drops during a number of weeks. Almost always, dryness passes off within 2-3 months after surgery, in some rare cases it lasts much longer.
Is there a possibility of complications during the surgery? If restrictions before and after the surgery are exactly fulfilled, possible complications are extremely rare. Inflammation is a common complication that may occur in surgery area. Such inflammation is treated by appropriate medications.
It’s also important to emphasize that after middle age (45) people require reading glasses. Meaning, even if after the surgery patient has a good long-sighting, he will require them with no doubt, like all his contemporaries who never required distance glasses in the past, and now they do require reading glasses.
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