Differences between ReLEx SMILE and LASIK
1. Method or technique- Flap (in LASIK) versus Flapless (in ReLex smile)
In LASIK, the word “LASIK” itself means that a “corneal flap” has been made. It could have been made using an instrument called ‘microkeratome’ or by using a ‘Femtosecond laser’- when it is commonly termed as ‘bladeless LASIK’. Regardless of method of flap-making, the word ‘LASIK’ means that there is a flap.Now, what is a ‘flap’ and why? …To treat your powers, one cannot work on the absolute first layer of the cornea (the transparent part of the eye which lies just above the circular coloured part). This first layer is very sensitive, and you would know this because even a single eyelash or any dust particle which you cannot see with your naked eyes, when it falls on this part, it is very sensitive. Hence, to treat your powers, one has to work under this first sensitive layer. How to reach there?… by lifting the first layer of the cornea. This layer is not ready-made, but needs to be created. It can be made, like mentioned above, using the microkeratome or using a Femtosecond laser. This is the first step in LASIK. The second step is using the laser which treats the powers (sort of “zaps” it off ) This is the excimer laser, and again, many brands are available in this. So, in LASIK there are two steps, one- make the flap, two- treat the powers.In Relex smile the two steps are different. The first step is to create a “lenticule”. Relex smile is for those where a flap is to be avoided or it is by choice taken by some people, as they fear the ‘cut’ made in order to make the flap. In Relex smile the concept is similar which is not treating the absolute first layer of the cornea, but to work under it. The Femtosecond laser bypasses the first few layers (no cut/ no flap) and creates what is called a “lenticule”, which in simple words is part of the corneal layer, if removed, removes or treats the powers or spectacle numbers. To create this lenticule, today only one company is allowed, ie Relex smile is done only through the Zeiss Femtosecond laser
2. Lasers used are different
In ReLex smile there is the use of only one laser- ie. the Zeiss Femtosecond laser. In LASIK, you can use various brands of excimer lasers to treat the powers. We use one of the most advanced laser platforms- the Wavelight 500 Hz laser. Also, in some cases of LASIK where one wants to undergo the bladeless method, there is also the use of the Femtosecond laser to make the corneal flap instead of using a microkeratome (again, various brands, and we use one of the best ie. the Zeiss femtosecond laser).
3. Recovery time is a little variedIt is said that the actual recovery (physical tissue recovery) from Relex smile is quicker. This is because there is not ‘cut’ or flap made. The small incision through which the lenticule is removed heals very quickly, by end of the day or next. And as there is no risk of flap related issues, one can resume activities like swimming, outdoor sports etc within the first week itself post smile procedures. In LASIK such energetic activities are usually allowed after 15 days to a month.
However, recovery also means visual recovery, and from our experience we have seen LASIK patients, by and large, get comfortable with activities involving computer screen time far more quicker than those with smile. Although permitted to use computers from the very next day, albeit in small breaks, we have seen that those undergoing smile take a tad bit longer to get comfortable for computer related work. In short, what one needs to expect in terms of recovery is:
A. Both Relex smile and LASIK procedure patients will be symptomatic on the day of the laser procedure, regardless of which type, they should expect their eyes to water, with itchiness, pricking sensation, poking sensations, inability to open the eyelids comfortably, heavy lids etc. This usually settles down by the end of the day or definitely by next morning, having decreased in intensity as time passes.
B. Both Relex smile and LASIK procedure patients will need to use antibiotic eye drops for a week to 10 days, and lubricating eye drops for few weeks post procedure.
C. Both Relex smile and LASIK procedure patients will be allowed to use computers, watch TV etc from the next day with breaks, drive when comfortable which maybe a week or so.
D. ReLex smile cases can be more active in terms of getting back to sports, swimming, outdoors etc. there is no risk of flap dislocation if you rub the eyes hard, as there is no flap in Relex smile. Hence, those habituated with rubbing or knuckling eyes are better off with this procedure. LASIK cases need to be more careful when handling the eyes as there is a flap which needs to settle in. Hence, all the above activities may take 15 days to a month to be permitted.