Frequently Asked Questions – ReLEx SMILE

What is ReLEx SMILE?

ReLEx SMILE stands for Refractive Lenticule Extraction – Small Incision Lenticule Extraction. It is a surgical procedure to correct common eye conditions such as myopia (short-sightedness) and astigmatism.

When was ReLEx SMILE introduced?

ReLEx SMILE was introduced to the public internationally in 2011. In the US however, it took another 5 years before it passed the strict regulations and safety standards of the FDA (Food & Drug Administration).

ReLEx SMILE utilises the ZEISS VisuMax femtosecond laser that was developed in 2006. Walter Sekundo, an award-winning ophthalmologist performed the first procedure using the laser in 2007. The reliability and predictability of the ZEISS VisuMax femtosecond laser make it suitable for performing various types of corneal surgeries, including ReLEx SMILE.

Is ReLEx SMILE a form of LASIK surgery?

No, ReLEx SMILE is not a form of LASIK surgery. Both ReLEx SMILE and LASIK however, are different types of laser vision correction. Due to the widespread popularity of LASIK surgery since it was introduced in the 1990s, LASIK has become synonymous with laser vision correction – for more information on LASIK, please read about it here.

eye refractive surgery

What are the 3 types of laser vision correction?  

ReLEx SMILE surgery is one of 3 types of laser vision correction. The other 2 are LASIK and Advanced Surface Ablation (PRK, TransPRK, LASEK, Epi-LASIK).

ReLEx® SMILE
LASIK
Advanced Surface Ablation (PRK, Epi-LASIK, LASEK, TransPRK)

What are the key features of ReLEx SMILE surgery?

ReLEx SMILE surgery is minimally invasive; it does not involve the creation of a flap like in LASIK. The procedure takes 15 minutes for both eyes, after which you may return home to recover.

By using the ZEISS VisuMax femtosecond laser, the ReLEx SMILE procedure gives accurate results for low to high degrees of short-sightedness and astigmatism.

Another difference of ReLEx SMILE from LASIK is that it employs one laser. This makes it convenient for the patient as there is no need to move from 1 laser station to another as in the case of LASIK with its 2 different lasers.

Other features of ReLEx SMILE are that it preserves the stability of the cornea by leaving the upper corneal layers intact, and that it reduces the incidence of infection and epithelial ingrowth leading to quicker recovery.

ReLex Surgery

Are there limitations to ReLEx SMILE?

ReLEx SMILE cannot correct for long-sightedness or for those with astigmatism only. If there is any need for enhancement or to finetune the prescription, the patient requires conversion to either LASIK or PRK.

What are the eye conditions that can be treated with ReLEx SMILE?

ReLEx SMILE is suitable for correcting:

  • Myopia (short-sightedness) for prescriptions of 100 to 1,000 degrees
  • Astigmatism for prescriptions of up to 350 degrees

How old must I be before I can be considered for ReLEx SMILE surgery?

You need to be at least 18 years old, the age when your eye prescription would have stabilised. In addition, if you are below 21 years old, you need parental consent for the surgery.

Can anyone undergo the ReLEx SMILE procedure?

In addition to the two previously stated conditions (prescription range and age), the following conditions need to be met:

  • Stable eye prescription during the past 12 months
  • Free of eye conditions such as glaucoma and cataracts
  • In relatively good health
  • No long-sightedness
  • Not purely having astigmatism; without short-sightedness
  • For women – not pregnant nor breastfeeding
  • Corneas that are not very thin, of irregular shape, nor steep (keratoconus)
  • Dry eye syndrome that is not severe (see next section)

If I have dry eye, can I get ReLEx SMILE done?

Yes, but only if your condition is mild and/or reversible.

An advantage of ReLEx SMILE over LASIK is that there is a smaller probability of dry eye syndrome occurring. After surgery, there may be an increase in dryness, but for most patients, the dryness is temporary and will taper off within 3 months.

For a small number of people however, the dryness may last up to 6 months. For an even smaller number of people; less than 1%, the syndrome may persist up to 12 months or more.

If you think you have dry eye syndrome, you should have it diagnosed and treated before having the surgery. Following this, you need to keep up with your treatment faithfully, otherwise the symptoms will reappear. This implies that you need to apply the prescribed eyedrops regularly even if you do not feel that you need to.

How will I be evaluated to determine if I am a candidate for ReLEx SMILE?

To determine if you are a suitable candidate for ReLEx SMILE, you need to go for a pre-laser evaluation. This includes a comprehensive range of eye tests that includes pupil dilation and consultation with your eye surgeon. The evaluation typically lasts 3 hours.

What do I need to do to prepare myself for the ReLEx SMILE evaluation?

Before the evaluation, you are required to stop using soft contact lenses for a minimum of 3 days. If you are using hard contact lenses, the duration is a minimum of 14 days.

Woman Eye Check

What happens during the evaluation procedure for ReLEx SMILE?

During the pre-laser evaluation, your eyes will be checked for corneal thickness, corneal shape, manifest refraction, visual acuity, intraocular pressure, etc.

Eyedrops will be administered to dilate the pupils. A temporary effect of pupil dilation is that you need to remove your glasses for near vision (far vision on the other hand remains unaffected). In addition, there may be increased sensitivity to bright lights so you might want to bring your sunglasses along. Note that the effects of dilation will usually wear off after 4 to 6 hours.

What happens after the evaluation for ReLEx SMILE?

There will be a consultation with the surgeon after the pre-laser evaluation. The results will be shared and the surgeon will discuss the options that are available to you – this will depend on the condition of your eye, your occupation and lifestyle:

  • Thickness of the cornea – Advanced Surface Ablation (ASA) is recommended if the cornea is thinner
  • Myopia – ASA is preferred if your eye prescription is low
  • Astigmatism – if your prescription is 350 degrees or lower and that there is short-sightedness present, ReLEx SMILE is able to correct the astigmatism
  • Occupation and lifestyle – if there is a risk of head or eye trauma in your job or sporting activity, then ReLEx SMILE is recommended

Do ask your surgeon questions and clarify any doubts that you may have regarding the procedure.

How safe is ReLEx SMILE as compared to LASIK since LASIK has been around for a much longer time?

Most people fear that underdoing laser vision correction may lead to blindness. This is because there is the misconception that the laser itself causes blindness. In reality, it is infection to the eye that cause some form of visual impairment, but these are usually rare and if they do occur, they are minor.

Both LASIK and ReLEx SMILE are comparatively safe procedures. The main difference between them is that in LASIK surgery, a flap measuring 22mm across the circumference is created on the corneal surface. ReLEx SMILE however is minimally invasive as no flap is created – instead, only a small incision of 2 to 4mm is made. As no flap is created, there is no risk of flap dislodgment occurring as a result of engaging in contact sports or working in an occupation that has a high risk of head or eye trauma.

Overall, ReLEx SMILE has proven results in maintaining corneal sensitivity, the speedy restoration of nerves (reinnervation) and having a low incidence of temporal dry eye syndrome.

What are the side effects of ReLEx SMILE surgery?

After the surgery, you may experience some side effects which usually disappear after several days/weeks:

  • Glares and haloes
  • Dry eyes
  • Vision that fluctuates mildly
  • Rare occurrence of infections and other complications

Can I have ReLEx SMILE surgery performed on both eyes at the same time?

Yes, most people will choose to have ReLEx SMILE surgery performed on both eyes at the same time to minimise your downtime after surgery.

If you prefer to stagger the procedures, you may also do so.

Some doctors recommend collagen cross-linking with ReLEx SMILE surgery – what is it and do I need it?

Collagen Cross-Linking (CXL) is essentially a top-up procedure for ReLEx SMILE that is done at the same session to strengthen the cornea. This is to:

  • Minimise the occurrence of Corneal Ectasia, a rare complication in which vision is degraded as the cornea loses the ability to maintain its shape.
  • Extend the duration of the results of the surgery.
  • Reduce the need for post-procedure enhancements.

The CXL procedure starts off with the application of Vitamin B2 drops to your eye during surgery. UV light is then shone on the eye for a duration of 1 minute to cause the collagen fibres in the eye to cross-link with each other. This procedure helps to strengthen your cornea and only adds 5 minutes to the overall duration of the surgery.

Although having CXL done is no guarantee of preventing a regression from occurring, it does reduce the tendency of it happening, as well as reducing the risk of Corneal Ectasia which may develop many years after the surgery.

How do I prepare myself for ReLEx SMILE surgery?

As per your preparation for the ReLEx SMILE evaluation, you need to stop using soft contact lenses a minimum of 3 days before the surgery, and a minimum of 14 days for hard lenses.

If you have decided to have Collagen Cross-Linking on top of your procedure, do not consume large amounts of Vitamin C a week before the surgery. Eating small amounts of fruits and vegetables containing Vitamin C, however, is fine.

What should I do on the day of the ReLEx SMILE surgery?

  • Do not put on any make-up, facial products or perfume as they may interfere with the performance of the laser equipment.
  • Eat light; you do not need to fast.
  • You may get someone to accompany you if you feel more comfortable doing so.
  • You should not be driving immediately after the surgery so take a cab or be driven home.
  • Bring along a pair of sunglasses as your eyes will be sensitive to light after the surgery.
  • Arrive early at the eye centre so that you have time to settle down and relax before the surgery.

What is the duration of the ReLEx SMILE surgery?

The surgery takes about 30 minutes for 2 eyes. However, including the preparation time, you should expect to spend a total of about 2 hours in the eye centre.

What occurs during ReLEx SMILE surgery?

The ReLEX SMILE procedure is performed under topical anaesthesia (a local anaesthetic is applied to numb the surface of the eye). The procedure can be divided into two parts:

  1. A femtosecond laser creates a lenticule (disc-shaped piece of corneal tissue) just beneath the surface of the cornea.
  2. The same laser then makes a small incision of 4mm in the cornea, through which the lenticule is removed. This results in a reshaped cornea that corrects the vision.
ReLEx® SMILE

Will I feel pain during ReLEx SMILE surgery?

No, the surgery is relatively painless. For some people, they may experience a slight sense of pressure and/or discomfort but this is felt only momentarily.

How long will it take to recover from ReLEx SMILE surgery?

Your vision will be blurry for the first 6 hours after the procedure. You will recover about 75% of your vision the very next day.

The rate at which your vision becomes fully stabilised will vary for individuals. For most, the vision will stabilise in 3 months.

How many days of medical leave will I be given for ReLEx SMILE surgery?

You will be given 3 days of medical leave to recover at home although some people choose to resume work/school after resting for a day or two.

How often do I have to return for follow-ups?

You are required to return for follow-ups; 1 day, 1 week, 1 month and 6 months after the surgery.

What must I do to ensure a quick recovery from ReLEx SMILE surgery?

Follow all medical instructions provided strictly. You will also be given eye shields for use while sleeping during the first week. This is to prevent the accidental rubbing of your eyes while you are asleep.

What happens if there is over- or under-correction after ReLEx SMILE surgery?

If there is over or under-correction within the range of +/-0.75 or more (which occurs in less than 2 to 5% of patients), you can have an enhancement done after 3 months or when the refractive error has stabilised.

Do the effects of ReLEx SMILE change over time?

According to studies, more than 95% of patients continue to enjoy good vision many years after having ReLEx SMILE done. There are, however, some patients (up to 6%) who may require an enhancement within 10 years after the surgery for the correction of short-sightedness, long-sightedness or astigmatism.

Is it okay to wear contact lenses after ReLEx SMILE?

Allow between 1 and 3 months after your surgery before reverting to wearing your cosmetic/coloured contact lenses. Note that after ReLEx SMILE, the shape of your cornea may be altered sufficiently to not allow your lenses to fit as well as before. They may also tend to fall out if you have dry eye syndrome. For these reasons, you should have your optometrist prescribe new lenses that are a better fit for your cornea.  

Is it okay to undergo cataract surgery after ReLEx SMILE?

Yes, it is okay to do so. In fact, whether you have cataracts or other age-related conditions such as glaucoma and macular degeneration, you can still undergo surgery to have them treated.

What is the cost of ReLEx SMILE surgery (in Singapore)?

There are a number of variables involved which make it difficult to make direct comparisons between the various packages offered by clinics and hospitals. The differences, however, are usually due to the following:

  • Evaluation before the surgery which includes suitability screening, consultation, etc
  • Follow-ups/reviews and enhancements, etc, after surgery

When doing your research, look out for hidden costs and paying for unnecessary add-ons.

The cost of doing ReLEx SMILE for both eyes at hospitals and private clinics can range anywhere between $5,300 and $6,500.

Am I able to use Medisave and insurance for ReLEx SMILE surgery?

In most cases, no. This is because your eyes are not considered to be suffering from any illness. However, if you have a difference in prescription between your eyes of at least 300 degrees AND if you are intolerant to wearing glasses and contact lenses, you may use your Medisave.

On the other hand, insurance policies usually do not cover laser vision correction procedures such as ReLEx SMILE. There are some policies however, with higher premiums that allow for it. You may also want to check with your company’s insurance policies as there are some that include it under their corporate benefits.

How do I choose the right doctor or clinic for ReLEx SMILE surgery?  

Here are some questions that you should ask before making your choice:

  • Does the surgeon/eye centre listen to your needs and provide an unbiased consultation?
  • Is there transparency in the pricing with neither hidden costs nor hard selling/upselling?
  • What are the credentials and experience of the surgeon and the clinic?
  • What is the percentage of patients who require an enhancement post-surgery?
  • How advanced is their equipment, in particular, the laser technology that is being used?
  • Do they offer a full spectrum of treatment choices to allow for a customised approach?
  • What is the level of service provided by the eye centre?

Your sight is precious, so ask these questions and base your choice on who you feel most comfortable with.