SMILE (small incision lenticule extraction) and LASIK (laser-assisted in-situ keratomileusis) are similar types of laser eye surgery intended for vision correction, which will provide a result of 20/20 vision, which means that it helps you to see clearer. The most prominent distinguishing feature of SMILE and LASIK is that an excimer laser is not used to remove corneal tissue in the case of SMILE. 

Smile V/s Lasik Eye Surgery

Use of Laser

A single Laser is used in SMILE, whereas in the case of LASIK, two different lasers are used. Zeiss Femtosecond laser is used in SMILE, which makes a small incision that allows extracting tissue from the cornea. Whereas in LASIK, firstly femtosecond laser is to create the flap on the cornea and a separate computer-programmed laser called an excimer is used to help the surgeon to remove a certain amount of tissue from the cornea to rectify vision problem.

Procedure

LASIK requires a two-step procedure. A narrow corneal flap is created using a mechanical microkeratome or a femtosecond laser as the first step of LASIK. In the second phase, the flap is lifted and excimer laser ablation is used to modify the stroma beneath the cornea to correct the patient’s unique form of ametropia. The moved flap acts as a natural bandage and facilitates rapid vision recovery.

Similar to LASIK, SMILE entails two surgical procedures. First, a femtosecond laser, rather than the traditional laser used in LASIK, is used to make two intrastromal incisions. A posterior refractive cut and subsequent anterior cap form the intrastromal lenticule. To correct the ametropia, the surgeon will physically anatomize and detach the lenticule, resulting in a reformed cornea.

Treatment of Refractive Conditions

Both procedures are safe, efficient, and practical, resulting in high patient satisfaction. LASIK is helpful for a correction of a wide range of refractive errors like Nearsightedness (myopia), Farsightedness (hyperopia), and Astigmatism (blurry vision caused by irregular cornea shape. But SMILE is approved for the treatment of nearsightedness and astigmatism only. Farsightedness cannot be treated with SMILE.

Postoperative Period

Both processes require similar postoperative care. It is not much different than LASIK patients have faster visual recovery, and usually, they get 20/20 vision on the following day of the operation. Whereas, in the case of SMILE, the recovery process may be longer than that of LASIK.

Flap v/s Cap

As SMILE is flapless eye surgery, it avoids all Flap complications like epithelial ingrowth or wrinkles on the corneal Flaps, which may arise from improper placement of the flap.

The notable difference in both processes is the size of the incision made. LASIK creates a 270 °90- circular flap incision. On the other hand, SMILE creates a smaller 90° incision into a pocket underlying a cap of tissue. Approximately a 3.8 mm keyhole incision is used in SMILE, which is less invasive as compared to LASIK’s 24mm flap cut.

Stronger Cornea

The cornea gets more robust after the SMILE surgery than after LASIK as it has approximately 1/5, i.e., 80% smaller side-cut on the corneal than LASIK surgery. The smaller corneal nerve distribution in the SMILE procedure results in regular production and improved regulation of tear production. Also, in the case of SMILE, more supportive anchoring fibers are present, which better preserves the anterior corneal structure.

Risk of Dried Eyes

The compact incision in SMILE keeps more nerves intact, benefiting patients more sensitive to dry eyes. As fewer nerves are cut in the SMILE procedure, the prevalence of dry-eye symptoms is much lower for SMILE, allowing a slightly rapid recovery time than LASIK. Besides, the sensitivity of the central cornea is maintained at a closer level than Lasik, which leads to less risk of post-surgery eye dryness.

Highly Controlled Procedure

Environmental room conditions with high corrections affect LASIK. On the contrary, SMILE doesn’t interact with the temperature or humidity of the room. As a result accuracy of the result of high and low correction is the same.

Recovery

Patients undergoing LASIK recovers a little faster than those having SMILE surgery. In the LASIK process, the entire Flap drapes around the surface, but in the SMILE case, the two surfaces require time to come closer and settle down in an inappropriate position.

Complications and Risk of Smile and Lasik Surgery

As the flap is not present in SMILE, the risk of dislocation is lower for SMILE than for LASIK. The risk of trauma is also less in the case of SMILE. As flaps can move when traumatized, LASIK is a bit risky. But as the SMILE cap is anchored, the risk of the cap shifting or moving is less.

Comparing the Cost of Smile and Lasik Surgery

Both forms of eye surgery are comparatively affordable. The difference in the cost of both procedures doesn’t deviate much. The cost of both processes for conducting double eye surgery ranges from INR 45,000 to INR 1,45,000, depending on several variables.

Limitations

Both processes involve some minor drawbacks. Patients undergoing LASIK treatment often face the potential sensation of dry eyes, burning, or itching due to the severed corneal nerves during the flap-creation procedure. SMILE surgery is unable to treat patients who have farsightedness. It can only treat patients with refractive errors caused by nearsightedness and astigmatism.

Making the right choice between Smile and Lasik

While making decision few questions should be given consideration.

In which of the process is the surgeon more comfortable?

Is the patient farsighted? If yes, Smile is not the right choice

Is there any history of dry eyes? If yes, SMILE will be a better choice.