With so many websites providing information about LASIK eye surgery, it can be somewhat confusing and overwhelming. We understand that this overload of information can create doubt and prevent you from fully committing to the LASIK procedure and throwing away your spectacles or contact lenses for good. We will walk you through LASIK eye surgery and give you an in-depth understating of the procedure and why it’s the best give you can buy yourself.
What is LASIK Surgery?
LASIK, or Laser-Assisted in-Situ Keratomileusis, is a surgical procedure that uses a laser to correct vision problems such as myopia (short-sightedness), hyperopia (far-sightedness) and astigmatism.
Benefits of LASIK
With today’s advanced laser eye surgery technology, many people can get laser vision correction to get rid of their glasses or contact lenses. LASIK eye surgery can be used to correct myopia (short-sightedness), hyperopia (far-sightedness), astigmatism, presbyopia and even age-related loss of vision.
LASIK can also be offered to patients who have had cataract surgery or refractive lens exchange and are seeking either independence from their glasses or to better-uncorrected distance vision.
If you are near-sighted, the goal of LASIK is to flatten the central cornea which is too steep. While if you are far-sighted, a steeper cornea is desired, and so the laser ablation is done in the peripheral cornea.
The LASIK procedure can also correct astigmatism by smoothing an irregular, or rugby-ball shaped, cornea into the preferred normal shape.
Bladeless LASIK Eye Surgery
During the LASIK procedure, an ultra-thin flap is made in the cornea with the use of a femtosecond pulse laser or FS200. This procedure is completely bladeless, and 2000 000 gas bubbles gently separate the layers of the tissue.
This is completely painless.
The FS200 laser that Dr Dylan Joseph uses, is one of two in South Africa. It is a mirror image of the world-class refractive centre at the Wellington Eye Clinic in Dublin, where Dr Joseph dedicated two years of his career to further his passion for laser vision correction.
Once the flap has been made in the cornea, it is folded back, and the corneal tissue underneath is removed using an EX500 WaveLight excimer laser. The flap is then gently placed in its original position, covering the area where the corneal tissue was removed.
The LASIK technology is so advanced that there are several customised profiles tailored to your cornea and your vision.
Think of the front of your eye as being a contoured hill with a few lumps and bumps on it. The LASIK system and diagnostic equipment can pick this up and smooth these bumps out to give you the best optical quality under all lighting conditions.
State of the art equipment is used to detect corneal pathology and is essential in the workup of LASIK. These include Pentacam, MS-39, Osiris aberrometer, Pentacam AXL and Topolyzer.
Dr Joseph uses a computer to adjust the laser to suit your prescription. You will be asked to look at a target light for a short time while the laser sends pulses of light to painlessly reshape your cornea.
The LASIK Procedure
Knowing what to expect on the day of the surgery is half the battle won.
Besides the information below, Dr Joseph meets with you in the pre-op chat lounge and runs through the entire procedure from start to finish.
During the procedure, he will talk you through it, making sure that you are informed throughout.
The actual surgery takes +/- 20 minutes.
Before your surgery, Dr Joseph will perform a thorough eye exam to ensure your eyes are healthy enough for the procedure.
The shape and thickness of your cornea, the pupil size, refractive errors (myopia, hyperopia and astigmatism), as well as any other eye conditions will be evaluated. The moistness of your eyes will also be evaluated, and a precautionary treatment may be recommended to reduce your chances of developing dry eyes after LASIK eye surgery.
A corneal topographer and topographer are used to measure the curvature of the front and back surfaces of your eye and create a “map” of your cornea.
You will also have the very thin layer of the cornea (epithelium) mapped using the new MS-39.
This helps immensely with not only the screening of laser vision correction candidates but also in the treatment.
If necessary, you will be evaluated with an aberrometer or advanced topographer for potential customised laser vision correction.
Dr Joseph will also note your general health history and any medications you are taking to determine if you are a suitable candidate for LASIK. Please note that you need to stop wearing soft contact lenses at least three days prior to your initial evaluation and a week prior to your surgery. If you wear hard contact lenses, they will need to be removed for two weeks prior to seeing Dr Joseph.
Before the Procedure:
On the day of your surgery, you will come to the office about an hour prior to the procedure to fill in and discuss the consent forms.
You will then relax in the pre-operative room, and if you have no contra-indications for taking a mild tranquilizer, we will give you a tablet to relax you before your surgery. Topical anesthetic eye drops and antibiotics will be instilled in your eyes at this time.
During the Procedure:
Dr Joseph will then run through the procedure with you and discuss the points you need to follow during the procedure. Once you are relaxed, you will be taken through to the theatre where you will be placed under the laser.
Your single focus during the procedure is to concentrate on a green flashing light. If you can remember that, it will make the procedure as accurate as possible.
Dr Joseph will then place a speculum between your eyelids, which will keep them open (so you do not need to be worried about blinking). You are free to either close or open your other eye, whichever is comfortable. During this time, keep thinking about that little green flashing light. Dr Joseph will then take a few pictures of the front of the eye, and you will feel the bed swing over to another laser machine – the FS200 – which creates the flap in the cornea using tiny air bubbles. During this time your vision will disappear, but only last about 40 seconds. It will then return but will be very hazy – this is completely normal.
Don’t panic, Dr Joseph talks to you every step of the way.
The bed will then swing back to the original position under the EX500 excimer laser. Dr Joseph then folds back the hinged flap to access the underlying cornea, the stroma, and activates the eye tracking. The tracking is so advanced on this WaveLight suite, that it tracks each pulse twice before it is delivered, and the laser delivers 500 pulses per second.
Yes, that math is correct. It has tracked your eye in all directions a thousand times before providing the full second’s treatment.
You will hear a buzzing sound during this time and may experience a slight burning sensation. This highly specialised laser uses a cool ultraviolet light beam to remove “ablate” microscopic amounts of tissue from the cornea to reshape it, refocusing light entering the eye for improved vision.
After the laser reshapes the cornea, the flap is then laid back in place, covering the area where the corneal tissue was removed. The eye is irrigated and cleaned, and antibiotic drops are instilled. The other eye is then done using the same procedure.
No bandages or stitches are required.
After the Procedure:
You will go home that day with both your eyes closed with hard eye shields protecting them. Your only compulsory activity is to sit back and relax and designate someone to drive you home and be at your beck and call for a few hours prior to follow up. Usually, the eye patches are removed the next day and antibiotic and steroid drops are initiated that evening.
If you want to have LASIK surgery, but want to know you are getting the laser treatment that best suits your eyes, read on.
WaveLight Refractive Suite Profiles
Let’s go through the different profiles that the Wave Light Refractive Suite has to offer:
The Wavefront LASIK optimised profile
This is the longest standing profile on the system and the backbone of most treatments.
Studies have been done using non-optimised profiles and found that the change in the shape of the cornea was inducing poor quality of vision during low light conditions.
So, Wavefront optimised corrections are aimed at maintaining the physiological state of the eye.
This pre-compensation is done by removing more tissue peripherally than conventional profiles, to retain the corneas natural prolate shape. This profile has long been the standard way in which laser vision correction is performed. Furthermore, studies have shown an increase in post-operative versus pre-operative vision in over 60% of operated eyes.
A patient survey also showed a significant improvement in daytime vision.
This treatment, however, only corrects for what your spectacles, contact lenses or reading glasses can correct, that is your spherical and astigmatic correction.
The Custom-Q or Asphericity Q-adapted profile
The Q-factor represents the rate of change of curvature of the cornea. Most people’s corneas (or better known as the front part of the eye) have a prolate form, steeper in the centre and flattening towards the periphery.
When laser vision correction is performed for short-sightedness, this typically flattens the central cornea. The opposite applies to people who are far-sighted. Koller and co-workers found that custom-Q treatments for myopic up to –9DS and astigmatism up to 2.5D are clinically equivalent to Wavefront-guided procedures which will be discussed next.
Studies show that the rate of change of the cornea was less impaired by the custom-Q procedure up to -5DS.
Ocular Wavefront LASIK-guided ablation profile
Wavefront-guided ablation profiles allow for your short-sightedness, far-sightedness and or astigmatism to be corrected in addition to other factors which may decrease the quality of your vision, known as higher order aberrations or HOA’s.
Since the first Wavefront-guided treatment by Prof Seiler in 1999, this has become the ‘gold standard’ for treatments with some laser platforms.
In this procedure, information is obtained from a Wavefront-sensing aberrometer and electronically transferred to the laser to program the ablation.
This is distinct from conventional excimer laser and Wavefront optimised laser treatments, in which the subjective refraction is used to program the laser ablation.
The Wavefront sensor gives us an indication as to the difference between an ideal Wavefront and yours, and generates a 3-dimensional map to plan the ablation. This profile is tailored to the total individual defects of your eye.
Most defects, however, come from the cornea where the laser is being done, making topography laser vision correction or Contoura the next visual frontier.
To measure the entire optical Wavefronts, a Hartmann-Shack or Tscherning aberrometer is used to capture deflection of the individual optical components of the cornea, lens and retina.
In most studies, there are mixed results when comparing Wavefront optimised to Wavefront-guided treatments, although Wavefront-guided treatments appear non-superior in non-aberrated eyes.
Topography-guided laser profile: Contoura Vision
Topography-guided ablations were originally introduced for use of corneal regularisation in eyes with irregular astigmatism.
By 2010, topography was further being implemented into treating short-sightedness, far-sightedness and or astigmatism, along with corneal irregularities.
We have special equipment that can take height measurement maps of the front of your eye, and map it, not dissimilar to a topographic map of the land, showing the contours. It also highlights all the ‘lumps and bumps’ in the optical system of the cornea. From this topographic map of your eye, elevation data is determined relative to a population-based reference.
This difference map generates the laser ablation profile, together with refraction data calculated directly from the map. It is, therefore, a profile adapted to your individual corneal contour, which also includes the aberrations from the corneal front surface.
Below are the results from the Alcon and WaveLight US T-CAT Study of LASIK for myopia and myopic astigmatism, essentially the first Contoura vision trials done.
Impressive statistics from the first graph are that almost 95% of people were within 0.5D of intended target one year after surgery. This has shown great stability beyond the year mark to date. The second graph shows cumulative data for an uncorrected vision from one month after surgery up until one year, with the majority being in the 20/20 bracket or better.
Further findings from this study were that there was an improvement in patient vision symptoms:
- Statistical significance was achieved for light sensitivity, difficulty driving at night, reading difficulty and glare with Contoura LASIK.
- Contoura Vision produced a 2-3-fold higher number of eyes with clinically significant increases in contrast sensitivity than decreases.
Is the LASIK Procedure Safe?
Are you concerned about potential side effects or complications of LASIK eye surgery? Here are the most common side effects that you may experience after laser vision correction.
We also provide you with a clear understanding of each possible issue that may affect your procedure or the recovery process of LASIK eye surgery.
Seeing that you’ve landed on this page, it’s excellent to know that you’re doing your homework on LASIK.
Before we continue, it’s important to realise that, just like any medical procedure, there are potential side effects and risks, but it’s about minimising these, and treating them if they do occur. Our professional team will be able to guide you through any side effects that may trouble you.
When you’re having LASIK with a highly trained surgeon, the risks are as low as possible. When we look at world-wide statistics regarding laser vision correction, LASIK and advanced surface ablation are among the safest surgical procedures. Not only are they one of the most commonly performed procedures, but LASIK is, in fact, the most commonly researched and published medical procedure in the world. It’s nine times safer than wearing contact lenses…now that’s food for thought.
Side effects and complications have their differences but can overlap somewhat. Below, we will try and make these issues as clear as possible, helping you to go ahead with the decision of a lifetime: one that will affect the future of your vision. Complications, on the other hand, are usually situations that happen as a direct result of the surgery, and in most instances, can be rectified straight away.
Let’s talk about glare and halos
On older generation laser treatment platforms, it wasn’t uncommon to induce halos and glare when changing the shape of the cornea with a laser (especially if you were very short- or far-sighted). This was because of the laser profile used. These optical problems are known as higher order aberrations, which were problems induced by the laser itself. Because of this, the Wavefront optimised treatment profile was developed, which enabled the lasers to maintain a more normal shaped or aspheric profile of the cornea. This, ultimately, decreases the chance of halos and glare.
So, instead of flattening the central cornea alone, there is a gentle slope towards the edges, making your visual quality better. The WaveLight refractive suite Dr Joseph uses has an incredibly good and optimised treatment profile, reducing, if not eliminating, the potential side effect of halos and glare.
Dr Joseph has even more advanced profiles, called Contoura™ vision, which he is very comfortable with. As a result, this really takes us up a level regarding optical or visual quality optimisation.
Another factor which may result in some glare after surgery is a naturally large pupil at night-time. If your pupil enlarges to a diameter bigger than that which was lasered, the light entering the eye will catch the edge of this lasered zone and can cause the classic halos that people may describe after laser vision correction. But this is exceptionally rare, and we will be able to pick this up at your time of consultation with our equipment that is able to measure pupil size, amongst a host of other parameters.
The general rule that can be applied if one does notice halos and glare appearing, is to give yourself one month per dioptre lasered for the halos and glare to settle and eventually resolve.
So, if you are a -4, it will take on average 4 months for the halos and glare to settle and in most cases eventually disappear. Conversely, some people already have, and are born with, the halos and glare built into their eye as each person’s eye is contoured and has minor ‘lumps and bumps.’
Standard laser profiles do not correct for these tiny aberrations in your visual system. But thankfully today, with the help of Contoura™ Vision, which the WaveLight offers, one can obtain vision that is superior to what you had in terms of quality than prior to the laser procedure.
What are the more common side effects of LASIK eye surgery?
- Light sensitivity
- Difficulty driving at night
- Reading difficulty
- Fluctuation in vision
- Foreign body sensation
It’s important for LASIK patients to not that light sensitivity is normal after any laser vision correction procedure. Not only can this happen after LASIK, but also after advanced surface ablation procedures like LASEK, PRK or trans-epithelial PRK.
Light sensitivity occurs partly because the nerves in your eyes have been disrupted and need some time to settle. This sensitivity can also be caused by your eye’s temporary dryness. The fact that you are no longer wearing glasses of contact lenses can also cause light sensitivity as your eyes get used to having a barrier protecting it.
New literature suggests that with ultra-thin flap LASIK of 100 microns, the postoperative incidence of dry eye is very similar to that of advanced surface ablation procedures, which was previously thought to be the go-to procedure if one had a history of dry eyes. With our femtosecond laser, which parts the tissue as opposed to cutting it, post-operative dry eye has reduced significantly.
Light sensitivity often goes hand in hand with a fluctuation in your vision quality. Your tear film, which normally lubricates the surface of your eye, is temporarily disrupted after the procedure. This results in changes in your vision in-between blinks.
Both side effects or symptoms described above are normally related to dryness of the eye. Dryness is usually temporary after LASIK eye surgery but could last up to nine months. We are meticulous about the pre-operative screening process and picking up dry eye and treating it prior to laser vision correction. If this does occur, we will nurse you through this phase with additional lubricants, and or anti-inflammatory drops.
Fluctuation in vision and foreign body sensation are usually also due to drying of the surface of your eye. Using plenty of preservative-free lubricants in the first month or two after surgery often does the trick.
If you have trouble driving at night, it could be because of the size of your natural pupil, and the fact that there is tissue swelling that needs time to settle down. It could also be a result of a small lasered optical zone, which is very rare these days. It also depends a lot on the type of laser being used or if you have had monovision where one eye is corrected for distance and the other for near. The latter can be corrected simply by wearing a pair of night-time spectacles.
Starbursts are an interesting phenomenon. Although lasers have the optimised profiles to try and reduce what we call higher-order aberrations, lasers can still induce these aberrations depending on the machine used. The WaveLight has the technology to reduce these total aberrations, so it is extremely rare to end up with starbursts after laser vision correction. Dry eyes, of course, can also induce these visual phenomena, which might be frustrating, but it is temporary.
Reading difficulty is more of a concern if you’re having LASIK and you are over 40-years of age. It is at this age that the body’s natural ability to read at about 40 cm starts losing ground, and we start suffering from the ‘short arm syndrome’ – pushing the book further away from us to get it into focus.
It is very important to discuss your options with your surgeon if you are approaching 40, or over 40. We are certainly able to discuss and simulate options to help keep your reading ability, as well as preserve your distance vision after laser surgery. Dr Joseph will go through this with you in depth at your time of consultation.
During Dr Joseph’s time abroad, 60% of his clients were in the 40-plus age group, already looking for solutions to get rid of reading spectacles. Knowing this, and having the access to the technology we have, it can now be done in the WaveLight Suite.
Let’s tackle common myths and misperceptions of LASIK:
Does laser vision correction wear off?
Lasering the cornea results in a permanent change in shape, which cannot ‘wear’ off.
There are, however, several factors which result in what we call ‘regression’. Basically, you start noticing some of the short-sightedness or far-sightedness starts creeping back in. If you spend a lot of time in front of a computer, growth in the length of your eye will be induced. Unfortunately, this could result in you becoming short-sighted again.
There are massive advances in the field of epithelial mapping, which holds the key to the causes of regression. We have access to a fantastic diagnostic device, the MS-39, at our clinic.
This device gives in-depth analysis into the healing of those epithelial cells after laser vision correction and the potential impact they have on the approach to correcting your vision again. While working at the Wellington Eye Clinic in Dublin, Dr Joseph routinely used the MS-39 and gained massive insight into its applications and was privileged enough to present the data we collected on it, to the world for the first time.
The beauty is not to panic if you notice your vision slips again. Usually, if you have had LASIK and you have enough tissue left, we can lift the flap if the original procedure was done within two years. Then, we will be able to repeat the laser treatment and then put the flap back down. If, on the other hand, the original procedure was done more than two years ago, it may become dangerous to lift the flap, and so we simply laser on top of the flap instead. The reason for this is that the flap is created by the FS-200 which is so accurate, that it makes the flap look like a manhole with precision made, tight fitting edges. Lasering on the surface of the flap is done as advanced surface ablation.
A side effect of this procedure is that the recovery time from a vision perspective is a minimum of a week, and often up to four weeks, and the sensation recovery. The sandy, gritty feeling in your eye, should be settled by about one week after the surgery, but it usually takes 2-3 days.
If the laser treatment wears off, it is essentially a misnomer, and your body’s response to the healing process and remodeling of tissue are what largely account for needing an enhancement. Looking at the general population, one will require an enhancement in 1-5% of the population who are myopic, has astigmatism, or mixed astigmatism (short-sightedness and astigmatism). This figure increases slightly to about 10% if you are far-sighted or have a ‘plus’ script in your treatment.
What about infection in the eye?
Any surgery to any part of the body carries a small risk of infection. Fortunately, we treat your eye with antibiotics prior to laser eye surgery to reduce this risk.
After the procedure, we give a good dose of antibiotic into the eye too.
With the LASIK procedure, if you develop an infection, which carries around a 1:10000 chance, it will always be underneath the flap. This is the easiest form of infection to treat. We simply lift the flap, rinse it out and increase your antibiotic dose and watch your eye closely. If you are having a surface treatment, however, like PRK, LASEK or trans-epithelial PRK, infection on the surface can be a little trickier to treat but is usually very manageable.
The risks are the same for both laser vision correction groups. Inflammation usually goes hand in hand with infection but can be separate depending on the situation. Depending on the degree of inflammation we can either watch and treat conservatively, or if moderate to severe, we take the more aggressive approach and can rinse underneath the flap. Fortunately, this too is extremely rare.
What about complications during the creation of the flap?
As mentioned, the FS200 laser creates the flap by driving 2 million tiny bubbles into a predetermined depth in your cornea. Dr Joseph monitors this process and if, at any point, he is not happy with the flap creation, we stop and send you home. These bubbles dissolve within 24-hours, and your vision returns to what it was. You can then safely return after a few months and we can repeat the laser procedure. This incidence is less than 0.1% using the WaveLight refractive suite.
What is ecstasia?
Your cornea is woven together with millions of collagen fibres. These fibres act like scaffolding holding up a structure. When laser is done, we are removing some scaffolding. Ectasia is the point reached where that scaffolding can no longer hold itself up and can very slowly change shape over time, which could impact visual quality.
Fortunately, with today’s strict screening parameters, we can pick up if your cornea is at risk of this and will offer you an alternative procedure.
In the very rare event, it may happen, even if your corneal structure looks normal, it can be picked up on the post-op scans, and we can do a procedure called cross-linking which essentially stabilises that scaffolding and prevents any further change in shape.
These are the most discussed potential side effects of LASIK eye surgery, but as you can see with advances in technology and the way in which these side effects are managed, most of them are a thing of the past, or short-lived.
LASIK Eye Surgery Recovery
The best advice on the same day of surgery is to take it easy.
Go home, kick your feet up, and have a well-deserved rest. If you need some pain medication, the clinic can inform you of what will work best after your eye treatment. You will have a script of medication to use for the coming week.
The next day, you will return to the clinic and have the shields removed before seeing Dr Joseph for a visual assessment.
This will be the first day where you are free of spectacles.
It will be an incredibly liberating experience for both yourself and Dr Joseph once you start noticing the difference.
LASIK is a beautiful procedure when considering visual recovery and comfort.
After LASIK eye surgery is performed, it is very common to feel like you are sitting in a smoky bar for the first four to six days. This settles every day until it eventually disappears. LASIK usually brings you visual recovery within one to six days after surgery.
So, if you wear spectacles or contact lenses, you can expect your vision to be as good, if not better than what your specs or contact lenses were giving you after the first week.
The EX500 WaveLight suite Dr Joseph uses has an exceptional laser profile that takes your vision under all lighting circumstances into account. It is not uncommon to experience some glare, and even halos after the surgery though. The easy way of remembering how long this will approximately last is to know that if you are short-sighted with a script of -3, then it will take approximately 3-months for those haloes and some of the glare to settle and then eventually disappear as your brain adjusts to your new vision. Most people, on the other hand, don’t notice glare or halos at all. In summary, it takes about one month per dioptre of short-sightedness for these symptoms to settle.
The other massive benefit of undergoing LASIK eye surgery lies in the comfort factor. (As you will have read in previous information, the procedure itself is completely painless.)
There is very little discomfort within the first 24-hours – in fact, it’s merely a mild discomfort or scratchy sensation. One in every four people do notice that their eyes stream with tears within this first day. This is completely normal, and you don’t need to worry about this at all. Make time to rest and take pain medication if necessary. You are also able to use preservative-free lubricants to soothe your eye.
There used to be plenty of talk around dry eye after LASIK eye surgery. However, this incidence is higher when a manual keratome or blade is used to create the LASIK flap. With femtosecond technology, for example, the laser parts the tissue as opposed to cutting the tissue. And so, the incidence of post-operative dry eye is far less. It is possible that you experience dry eyes after the surgery, but this is temporary as a result of LASIK. If this occurs more frequently, we will nurse you through this phase with plenty of lubricant eye drops and possibly some anti-inflammatory drops too.
What does LASIK Cost?
To find out what LASIK eye surgery costs and your options, contact us today.
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Dr Joseph pioneers advanced laser eye surgery in South Africa
Posted on September 02,2019
By Dr. Dylan Joseph