Introduction

What is SMILE Surgery?

SMILE (Small Incision Lenticule Extraction) is an advanced, minimally invasive laser surgery designed to correct common refractive errors such as nearsightedness (myopia) and astigmatism. It is a relatively newer alternative to the more traditional LASIK procedure. Unlike LASIK, which requires the creation of a corneal flap, SMILE involves only a small incision, making the procedure less invasive.

In SMILE, a femtosecond laser is used to create a small, disc-shaped piece of tissue, known as a lenticule, within the middle layer of the cornea. Once the lenticule is formed, it is extracted through the small incision. The cornea naturally heals around the incision without the need for stitches or additional sutures. The entire procedure is performed without cutting a flap, which helps preserve the structural integrity of the cornea, leading to potentially faster recovery and fewer complications, particularly in terms of dry eye symptoms.

What is LASEK Surgery?

LASEK (Laser-Assisted Subepithelial Keratectomy) is another laser eye surgery technique, and it is closely related to PRK (Photorefractive Keratectomy). In LASEK, the outermost layer of the cornea, known as the epithelium, is temporarily loosened using a diluted alcohol solution. This allows the surgeon to access the underlying corneal tissue, which is then reshaped using an excimer laser to correct refractive errors like nearsightedness, farsightedness, and astigmatism.

Once the laser reshaping is complete, the epithelium is repositioned over the cornea, and a protective bandage contact lens is placed to help with healing. LASEK is considered a surface-level procedure, meaning it does not require cutting into the deeper layers of the cornea, unlike SMILE or LASIK. This can make LASEK a preferable option for individuals with thinner corneas or other unique corneal characteristics that may not be ideal for flap-based procedures. However, recovery tends to take longer than with SMILE or LASIK, as the epithelium needs time to heal and regenerate.

Complications in SMILE Surgery

Though SMILE is considered to have a lower risk of certain complications compared to traditional LASIK, it still carries some risks. However, the minimally invasive nature of SMILE leads to fewer overall complications.

1. Dry Eye Syndrome

• SMILE is known to result in less disruption to the corneal nerves, which are responsible for tear production. As a result, the incidence of dry eyes is typically lower in SMILE compared to traditional LASIK or LASEK. This is a significant advantage for those concerned about prolonged dry eye symptoms.

• While dry eye can still occur after SMILE, the risk is generally lower, and recovery tends to be quicker compared to LASIK, as the nerves are not as affected.

2. Flap-Related Complications

• One of the key benefits of SMILE is that there is no need for creating a corneal flap, unlike LASIK. This eliminates flap-related complications such as flap dislocation, wrinkling, or infection. However, with SMILE, there is still a small incision, which is associated with a slightly higher risk of infection than non-incisional procedures like LASEK.

• While this risk is still quite low, it is something to consider if you are looking for a procedure with fewer risks in general.

3. Over- or Under-Correction

• While SMILE is highly precise, there is still a slight risk of over- or under-correction, especially in cases where the patient’s refractive error is very high. However, the advanced technology used during SMILE allows for greater accuracy, minimizing these occurrences.

4. Infection

• Because SMILE involves an incision, there is a potential risk of infection. However, the small size of the incision makes this risk relatively low, especially when compared to flap-based LASIK procedures.

5. Visual Disturbances

• Some patients experience visual disturbances like halos, glare, or double vision, particularly during the night. These are generally temporary and tend to resolve as the eye heals.

Complications in LASEK Surgery

LASEK, while effective, has a different set of risks and potential complications compared to SMILE.

1. Dry Eye Syndrome

• LASEK can lead to significant dry eye issues, especially in the early stages of recovery. Since the outer layer of the cornea (epithelium) is removed and reformed, there is a higher chance of irritation and dryness compared to SMILE. This often requires the use of lubricating drops for an extended period, sometimes several months.

• If you already have a tendency toward dry eyes, LASEK might not be the best choice for you.

2. Pain and Discomfort

• The recovery process for LASEK tends to be more painful than SMILE due to the removal of the epithelium. The patient may experience significant discomfort for the first few days after surgery, with a sensation of grittiness, itching, or a foreign body feeling in the eye. This discomfort is generally managed with pain medications and lubricating drops.

• In contrast, SMILE is generally less painful because it involves fewer surface layers of the cornea.

3. Longer Recovery Time

• Recovery after LASEK tends to be longer than with SMILE. Since the epithelium needs to heal and grow back, patients may experience blurry vision, light sensitivity, and discomfort for a longer period (usually a few weeks).

• With SMILE, the recovery is typically quicker, with most patients seeing significant improvement in vision within a few days and minimal discomfort.

4. Corneal Scarring

• In some rare cases, scarring can occur in the corneal tissue after LASEK, leading to reduced vision quality. This is more likely if the patient does not follow aftercare instructions properly.

• While SMILE does not involve the same level of corneal disruption as LASEK, there is still a potential risk of scarring, but it is usually less pronounced.

5. Infection and Inflammation

• Like any surgery, LASEK carries a risk of infection. The potential for infection is higher than with SMILE due to the removal of the corneal epithelium. Patients must follow aftercare instructions closely, including the use of antibiotic eye drops and protective contact lenses during recovery.

• The risk of inflammation is also higher, as the healing epithelium can become irritated or inflamed.

Which Procedure Has Fewer Complications?

• Dry Eye Syndrome: SMILE generally causes fewer dry eye symptoms due to less nerve disruption.
• Pain and Discomfort: LASEK tends to cause more discomfort, as the outer layer of the cornea is removed.
• Recovery Time: SMILE offers a faster recovery with fewer complications, while LASEK requires more healing time.
• Infection: While both procedures have low infection risks, the smaller incision in SMILE reduces the likelihood of infection compared to LASEK's surface disruption.
• Flap Complications: SMILE doesn't require a flap, eliminating related complications, which is a significant advantage over LASEK.

Conclusion

Both SMILE and LASEK are proven, effective methods for vision correction, but they come with different risks and recovery experiences. SMILE is known for its faster recovery, fewer complications with dry eye, and minimal discomfort, making it a strong choice for many patients. LASEK, while still highly effective, may involve more discomfort and a longer healing period, with a higher potential for dry eyes and other surface-related issues.

Ultimately, the best choice between SMILE and LASEK will depend on your individual eye health, lifestyle, and preferences. At Jryn Eye Clinic, we specialize in personalized care, using the latest technology to ensure the best outcomes for each patient. If you’re considering either of these treatments, we recommend scheduling a consultation with Dr. Han Sang Yeop and our team of experts, who will guide you through the decision-making process and help you choose the most suitable option for your vision needs.