Everything you need to know about ReLEx SMILE Treatment

Relex Eye Surgery

Suffering from nearsightedness? Do you have laser surgery as an option in your mind? Hold on. There are new and advanced methods for treating this problem. SMILE or ReLEx SMILE(Refractive Lenticule Extraction, Small Incision Lenticule Extraction) is a treatment that is a further development of Femto-LASIK procedure. It works by giving a safe and gentle correction of ametropia. It combines femtosecond technology with high precision lenticular extraction.

SMILE laser Surgery

It is a form of bladeless eye surgery. ReLEX SMILE or Small Incision Lenticule Extraction corrects deformities like shortsightedness and astigmatism. Though there are other traditional methods to treat these problems, eye specialists recommend SMILE as it has excellent advantages.

Facts about ReLEX SMILE surgery

  • It is performed using a VisuMax femtosecond laser which has worldwide recognition as Carl Zeiss Meditec makes the technology.
  • SMILE can correct up to -10.00 diopters of nearsightedness.

The science behind the procedure

SMILE laser eye surgery is made using a VisuMax femtosecond laser. The surgeon uses the laser to create a small, lens-shaped bit of tissue (lenticule) within the cornea. Then, a small arc-shaped incision is made in the surface of the cornea, and the surgeon extracts the lenticule through this incision and discards it.

Eligibility for this treatment

The person has to be 22 years and above. They should have no more than -0.5 D of astigmatism and their eyeglasses prescription should be stable for at least 12 months.

ReLEX SMILE over traditional LASIK

  • In LASIK surgery, a large opening is made to reshape the cornea. However, SMILE has an opening as small as 4mm to treat the cornea.
  • LASIK surgery involves cutting a flap and folding it backwards to remove corneal tissue. On the other hand, ReLEX SMILE uses a minimal procedure and does not require any flap folding.
  • LASIK tends to generate more tears. ReLEX SMILE is suitable for dry eyes as it uses an advanced technology called a keyhole. This keeps the cornea stable, and the flow of tears is hardly disturbed.
  • While LASIK uses a traditional method of surgery, ReLEX SMILE uses 100% femtosecond technology that is recognized worldwide and has a very high reputation. It is also considered to be the safest and most precise method of correcting visual disorders.
  • Short-sighted patients up to -10 diopters can be treated with the ReLEx SMILE procedure. The Femto-LASIK treatment was only recommended to patients with the refraction up to a maximum of -8 diopters.

Furthermore, it is even suitable for patients with higher ametropia, thinner cornea or dry eyes. A thinner cornea (min. 480 micrometres) is also not an issue because with the ReLEx SMILE procedure, it remains fully intact and the tissue ablation does not go as deep.

In contrast to Femto-LASIK, the nerves in the upper corneal layer, necessary for the regulation of the tear film, are retained mainly reducing the risk of dry eyes after the operation. A further advantage is that pain or a strong feeling of a foreign body on the cornea is not felt with ReLEx SMILE since laser treatment takes place inside the cornea.

Relex and lasik Surgery

Safety tab

To be precise, it is very safe. The entire idea which conceptualized SMILE is based on how to make laser procedures that exist today, such as LASIK, even more reliable, stable and long term. It is free from flap related complications possible with other forms of LASIK. The cornea is biomechanically more stable after ReLEx SMILE as the incision made on the cornea is 80% smaller than the flap cut made during conventional LASIK, minimizing the chances of late corneal thinning and ectasia and also a dry eye.

Benefits of ReLEX SMILE

  • Minimally invasive – The incision done through SMILE is 80% smaller than the one in LASIK. This incision enables the cornea to have more biochemical stability.
  • No flaps – Unlike in the conventional LASIK procedure, SMILE procedure does not require any flap folding, which often leads to displacement issues.
  • Preserving upper corneal structure – Since the upper corneal is untouched, the stability of cornea is largely unaffected
  • Night Vision – Less induction of optical aberrations.
  • Visual Acuity – 88% had a visual acuity of 20/20 or better post SMILE.

Limitations of ReLEX SMILE laser surgery

  • SMILE can only correct myopia, whereas LASIK and PRK correct significant amounts of farsightedness and astigmatism.
  • Also, LASIK and PRK can treat Higher-Order Aberrations (HOAs) that can affect night vision, whereas SMILE cannot. SMILE might increase HOAs to some degree.
  • If you have residual Refractive Error after a SMILE procedure and require additional vision correction, typically PRK would be the preferred enhancement procedure for best results.

Ensure you know your eye history before undergoing any LVC procedure to minimize any possible complications and risks and to maximize the benefits of ReLEx SMILE.

Finally, as with any newer vision correction surgery, it may be necessary for a surgeon to perform a significant number of SMILE procedures before he or she masters the surgical techniques required for optimum outcomes and minimal risks. Keep this in mind when considering SMILE (versus LASIK or other vision correction procedures) and discussing the procedure with your refractive surgeon.

The LASIK or laser eye treatment should not be performed, if you suffer from any of the following: –

  • Uncontrolled vascular disease or autoimmune disease.
  • Immune-compromised or on immunity-suppressing drugs or have a previous history of keloid formation.
  • Pregnancy, nursing, expecting to become pregnant within six months following the LASIK procedure or on hormone therapy for gynaecological dysfunction.
  • Have residual, recurrent, or active eye diseases or abnormality except for myopia or hyperopia in either eye.
  • Have any active or residual systemic diseases likely to affect wound healing capability.
  • Had herpes infection of the eye in the past.
  • Have unstable or uncontrolled diabetes.
  • Have progressive myopia or hyperopia [unstable spectacle power].
  • Amblyopia (lazy eye); glaucoma; severe dry eye.

ReLEX SMILE indication for myopia and astigmatism

  • Sphere: -0.50 to 10.00 D
  • Cylinder: 0 to 5.00 D
  • Spherical Equivalent: -0.50 to -12.50 D


Step 1: Creation of the lenticule and the incision

Creation of the lenticule and the incision with VisuMax, a 2 mm tiny incision is created in the cornea, and the refractive lenticule is created. This leaves the upper layers of corneal tissue mostly untouched. In a single step, the VisuMax takes about 30 seconds to precisely create a refractive lenticule (a thin lens-shaped corneal tissue) within the cornea inner layers & a small 4mm incision on the intact cornea surface.

Step 2: Removal of the lenticule

The lenticule is removed through the incision with only minimal disruption to the corneal biomechanics. The refractive lenticule is then removed through the small incision. Cornea structure remains undisrupted & stable.

Step 3: Rehabilitation

Removing the lenticule changes the shape of the cornea, thereby achieving the desired refractive correction. The removal of the refractive lenticule changes the way light bends into the eye, allowing you to see clearly once again. The micro-incision self heals.

LOTUS as the first option

Lotus Eye Hospital & Institute was the first eye hospital to introduce Multiscan Lasik in 1998. Lotus was the first eye hospital to introduce EpiLasik technology in South East Asia. Now Lotus has launched the World’s latest laser technology Zyoptix -217P in 2011. We always update new technologies as and when introduced.

We have performed over 35,000 Lasik procedures in addition to Epilasik, Intralase Epilasik, Zyoptix Ultimate, Intralase Zyoptix Ultimate, Zyoptix Supracor, etc., We have also received Best Performer Award from M/s.Bausch & Lomb for performing the highest number of Lasik procedures in India, in 2006. laser Eye Surgery in Tamilnadu can be experienced with doctors under personalized care in Lotus Eye Hospital and Institute. We are also one of the Best Eye Hospital in Kerala to provide Lasik Eye Surgery.

Common Questions related to ReLEx SMILE

Painless/ Flapless – Long-term stability with least or no complications. It is also a painless procedure.

No, there are no diet restrictions.

The opening required to extract the lenticule is 80% lesser than the conventional procedure. The structure of the cornea remains more intact.

We have been doing ReLEX since 2015 and do a minimum of 15 procedures per week. 90% choose ReLEx over LASIK when given options.

The success rate is pretty sizable, and patients have suffered no complications like permanent dry eyes, night vision issues, etc.

Ectasia is the side effect of LASIK treatment. ReLEX SMILE was brought in to eliminate this problem. Hence the latter has zero or no chances of ectasia.

Farsightedness is mainly caused by LASIK or PRK procedures, and they can be treated as well.

FAQ'S related to Procedure

About 15-20 minutes for both eyes.

A mandate rest of 24 hours post-procedure is recommended. The day laser is performed, you have to be indoors. A 3-4 days’ of rest is advisable as an extra caution.

Yes, both eyes are generally treated on the same day.

Yes. However, you will feel no pain as we put anaesthetic eye drops. This might give a little numbness or heaviness in your eyes.

Yes, as of now, studies and practicals state that this treatment is permanent.

Since there is no tissue distortion, SMILE procedure can be said to be accurate.

Since we follow a strict hygiene protocol, we have never faced any infection issues with our patients. We provide complete disposable laser kits that are safe and clean.

Dry eyes issues are nearly minimal or zero with ReLEX SMILE procedure.

Your vision will start improving in a few hours and will be near normal after the first 24 hrs. However, the vision may be slightly hazy for some patients and gets back to normalcy over the next 2-4 weeks.

Hair wash can be done after two days.

Pre-procedure & Post-procedure Clarifications

You should discontinue wearing soft lenses 3-4 days before the evaluation or consultation from the doctor.

Yes, to a certain extent for those with higher numbers, the Lenticule is thicker. Please also note this Lenticule or the thickness of this Lenticule that would be removed during SMILE is the same amount of the cornea which would be vaporized in LASIK.

Yes, until the doctor examines you, post-procedure.

You can resume your routine in 2-3 days.

No, not necessarily. Usual home light is acceptable. Some may have light sensitivity for a few hours after the procedure, during which time they must shut and rest their eyes. You can start watching TV, or read, and get back to routine as soon as you are feeling comfortable.

As the person’s age increases, the ability of the eye to focus on nearby objects decreases. This being age-related process is irreversible and called is Presbyopia. Hence everyone above 40 years will need reading glasses even after the laser procedure. But your distance vision will remain corrected.

Till date, we have not re-treated any patient who has undergone ReLEX SMILE procedure. Even studies published worldwide showed a near-zero re-treatment rate. However, if needed, please note that the re-treatment carried out would be a surface ablation laser treatment, not requiring all steps of SmILE to be repeated.

You need to stay indoors only on the day of the procedure. You will need to visit us on the next day for the follow-up and may resume work the following day. There is no need to be indoors after 24 hours.

It is not only after this procedure but a general principle that you don’t wash your eyes with the regular tap water. This is in contradiction to what we have all been hearing while growing up. The regular water does not contain the same salt concentration as the tears that bathe your eyes.

Water is irritating to the eyes. We recommend lubricating eyedrops that give a good PH balance for the eyes. In the healing process after the procedure after LASIK, the corneal nerves are regenerating in the flap. The new nerves that grow in are hypersensitive to irritation so it would be common to notice irritants like pure water, wind or smoke in the eyes more than usual.

Once the nerves fully heal, the increased sensitivity goes away, and the irritation sensitivity returns to normal for most patients. If this is happening while swimming, you could consider using goggles.

You can start wearing eye makeup and do beauty treatments after 15 days, and after having checked with our doctor on your post-treatment visit. Cosmetic contact lenses can be worn after consultation with your surgeon, but are usually allowed a month later.

Just for the first few days, it is compulsory to use some protective Sunwear outdoors, which we hope becomes a good habit. Indoors, you will be asked to wear anti-fatigue computer glasses which will be prescribed after the procedure.

This is done not for cutting glare but more to reduce the risk of getting some powers again in future due to excessive computer usage.

No, the Lenticule is removed from within the thickness of the cornea. In fact, in SMILE, there is no “cut” or “flap” which in theory, is supposed to be the reason why SMILE treatment was created. That is, to keep it independently or to strengthen the cornea.

After any laser surgery when you remove the powers, a certain amount of cornea is used up. Hence, the cornea before and after any laser cannot be the same. However, this is the very reason why you need to go to a surgeon with good experience who can differentiate and find out cases when laser should not be done, i.e., people who tend to have weaker cornea post-surgery.

With advanced technology and most experienced eye specialists, we stand as the best eye hospital in India. We make sure of providing and explaining the best solutions for our patients who come for consultations. We work in the best interests of those who come to us.

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