SMILE, LASIK or PRK: which technique should you choose?

“Doctor, do you do SMILE?” It is about the only technique people ask me for by name before they have even met me. The answer is yes. But I also answer, every time: come and see me, and we will talk about it. Because there is no best technique in absolute terms. If there were one, it would be the only one performed.

The choice depends first on your eyes, then on your life. And when several techniques are possible, we make it together.

What patients have in mind when they arrive

Most patients know little about the techniques. They come with what they have been told. A friend who had LASIK and could see perfectly the next day. A colleague who was in pain for several days after PRK. A video about a flap that supposedly moved. Or the idea that SMILE, newer and without a flap, must be better.

Each of these stories holds some truth, but none is enough to choose. So, in a nutshell, here are the three techniques.

LASIK. A thin flap is cut at the surface of the cornea, the laser reshapes it underneath, then the flap is laid back down. Discomfort, sometimes painful, is possible during the first 5 to 6 hours; after that, vision is already good and the pain has gone. It is the technique I offer most often, boxers included.

SMILE. The laser cuts a thin lens inside the cornea, which is removed through a small incision, without a flap. Visual recovery is a little slower than with LASIK: 24 to 48 hours, versus a few hours. I readily offer it to people who must quickly return to an activity exposed to blows, combat sports or otherwise.

TransPRK. The laser works directly on the surface, with no cut and no flap. Pain in the first days varies a great deal from one patient to another, and vision takes a little longer to stabilize. I turn to it when the cornea is thin, the prescription high or the eyes dry.

The assessment looks at your eyes, and at your life

The pre-operative assessment is an assessment of the eyes: thickness and shape of the cornea, prescription, ocular surface. It is also an assessment of the person. I look at your job, your sports, how soon you need to be back at work. I also look at what frightens you: the pain of the first days, the flap, a particular complication you absolutely want to avoid.

All of this counts as much as the measurements.

Three common situations

A young -4 myope who boxes. Boxing is not a contraindication to LASIK. A glove is larger than the eye socket: the punch stops on the bone around the eye, as I explained in detail in an article on boxing after LASIK. I ask patients to stop combat sports and ball sports for about three weeks, then they can resume. Bare-handed fighting is a little more exposed. The risk remains very low, and a dislodged flap, treated promptly, generally recovers well.

A 35-year-old woman with dry eyes. Before choosing a technique, I look for the cause of the dryness: allergy, poorly tolerated contact lenses, a hormonal factor, inflammation of the eyelid margins. It is treated first, then we see whether things improve. After that, I tend toward TransPRK. And sometimes I plan ahead by placing tear duct plugs during the procedure: these small plugs, placed at the entrance of the tear ducts, keep tears on the surface of the eye during healing.

On paper, studies that measure the tear film show differences: dryness is more marked after LASIK than after PRK or SMILE [1, 2]. In real life, however, my patients’ feedback is comparable from one technique to another, including after LASIK, and the vast majority do well.

A -8 myope with a slightly thin cornea. LASIK and SMILE require a fairly thick cornea, especially for a -8 correction. For LASIK, the proportion of the cornea altered by the procedure is one of the main risk factors for ectasia, a progressive deformation of the cornea [3]. In this case, I tend toward TransPRK, which preserves more thickness.

When there is no choice

Sometimes only one technique is possible, and I explain it. Sometimes none is: very high prescription, cornea too thin, fragile, deformed, or suspected of keratoconus. What remains then is the implant, provided there is room to place it in the eye, which is not always the case, particularly in high hyperopes. I then refer you to a colleague who places these implants (see the alternatives to laser).

When several techniques are possible, we decide together

I explain everything, with my advice, and the decision is made together. It can also change. Sometimes a patient comes back a few weeks later: “Actually, I’d rather avoid PRK, I can’t stop working for that long. Is LASIK possible?” If it is possible, the answer is yes. Conversely, some patients cleared for LASIK come back because the flap worries them. We talk it over again, and adapt if their eyes allow.

Three myths I often hear

SMILE or LASIK?

Myth: “SMILE must be the best, because it’s the newest.”

Not necessarily. SMILE is an excellent technique, which I perform. But LASIK and TransPRK are excellent too, and depending on your profile, one or the other may suit you better.

PRK or LASIK?

Myth: “PRK is the old technique, the one that hurts.”

Yes and no. I almost always perform TransPRK, in which the laser itself removes the surface layer of the cornea, without scraping it. In the operating room, it is more pleasant for the patient. And afterwards, I see fewer systematically severe pains than with conventional PRK, which comparative studies also report [4]. Some patients still have pain, but it is more variable. With TransPRK, in my experience, roughly: one third have almost no pain, one third have strong but bearable discomfort, and one third go through real peaks of pain for a few days.

The LASIK flap

Myth: “LASIK is frightening: a flap is cut in your eye.”

When I describe the steps, some patients get worried. In reality, everything goes very fast, and the sensations are not so different from TransPRK, which involves no cut and no flap: a little water, some pressure, hands around your face, shadows passing by. Most patients do not really realize what is being done. Experience matters: operating a lot makes it possible to perform these steps quickly and calmly.

In summary

There is no single right technique; there is the right technique for you. It depends on your eyes first, then on your life, your constraints and your fears. That is the whole purpose of the pre-operative assessment: to explain the options to you, and to choose together.