What are the complications of ReLEx SMILE?


As the up-and-rising star of laser eye surgery, ReLEx SMILE is often marketed as a procedure which is “gentle”, “minimally-invasive” and “flapless”. SMILE is in short for Refractive Lenticule Extraction, Small Incision Lenticule Extraction, a long mouthful of words which is known for its characteristic features –“lenticule extraction”. In SMILE, you will not need to cut out a cornea flap like what happens in LASIK, but just a minute incision will be required. But you may wonder, is it really as harmless as what the clinics claim?

In this article, we will focus more on the complications which are very specific to ReLEx SMILE. Will you will be able to smile after the surgery?

It is true that ReLEx SMILE is less invasive than LASIK.

Without a doubt, we know that ReLEx SMILE is less invasive than LASIK. ReLEx SMILE involve the extraction of a flap lenticule instead of cutting a cornea flap as in LASIK. The SMILE procedure requires a smaller incision (often less than 4 mm) as compared to LASIK (about 20 mm). With nerve cornea endings being cut, the risk of permanent dry eyes with ReLEx SMILE is lower than that of LASIK.

Therefore, if you were to undergo ReLEx SMILE, you won’t have to worry so much about flap complications and chronic dry eyes syndrome.

In place offlap complications, ReLEx SMILE is inter linked with lenticule complications.

Unbeknownst to the general public, one of the main concerns of ReLEx SMILE is ironically the key star of the procedure itself – aka the lenticule.The lenticule is thin and delicate, and may tear halfway during the extraction. [1] This makes the procedure even more challenging and time-consuming.

Lossofsuction – isitevenpossible?

Yes, this is actually one of the possibilities! The ReLEx SMILE procedureis performed under a gentle, low suction condition – which can be a double-edged sword. On one hand, it will not cause a “black out” phenomenon like what happens in LASIK. However, though the incidence rate is low, loss of suction is a possibility where the doctor performing the procedure is inexperienced, or the patient has a deep-set eye or in the case of uncooperative patients.

It is important thing you should be aware is that if this happens, the ReLEx SMILE procedure may even be aborted midway in exchange for other laser eye procedures like LASIK or TransPRK instead at a later date. [1]

Complications which are common to all laser eye surgeries.

Blindness may be one of the theoretical risk of laser eye surgery, but in reality, you will be relieved to know that this risk is very low. In fact, it is more likely for you to be caught in a road accident (touchwood!).

Other complications include the risk of infection, cornea scarring (from excessive exposure to the UV rays of the sun), under- and over-correction, glares and halos. They tend to be rare, nonetheless, always follow closely to your doctor’s advice and proper post-op care to ensure that your recovery journey will be smooth.

Final Thoughts on ReLEx SMILE.

Considered as an improvement to the LASIK procedure, ReLEx SMILE performs the procedure without having to cut a cornea flap, ridding you of the various flap-related complications and minimizing the chronic dry eyes. The ReLEx SMILE procedure is undoubtedly an important leap forward to reach the ideal laser eye surgery technique.

Nonetheless, it comes with its own set of risks and complications. Looking for more info about ReLEx SMILE surgery? Read more about the most Frequently Asked Questions about ReLEx SMILE surgery in Singapore!


[1] Titiyal J. S. et al (2018). Small incision lenticule extraction (SMILE) techniques: patient selection and perspectives. ClinOphthalmol. 2018; 12: 1685–1699.Published online 2018 Sep 5. doi: 10.2147/OPTH.S157172

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