LASIK, PRK, SMILE, EVO ICL or Lens Exchange: Which Is Right for You?

Start with age

Age is the first sorting question because the eye's natural lens changes in the mid forties. Before then, the lens is flexible and the prescription is the only problem to solve, which is what the corneal procedures and the ICL do. After about 45 the lens stiffens, reading needs help too, and reshaping the cornea does not address that. Patients in that group are usually better served by Refractive Lens Exchange, which replaces the lens with one that provides distance and near vision, and which means they will never develop a cataract, although the lens capsule can cloud later, which is treated with a quick laser.

Then the prescription

Corneal procedures remove tissue in proportion to the prescription, so there is a ceiling. LASIK and PRK treat nearsightedness up to roughly -10 to -12 diopters and SMILE up to about -10, depending on corneal thickness and the surgeon's assessment, and LASIK and PRK also treat farsightedness. Above that range, or at the top of it in a thinner cornea, the EVO ICL corrects up to about -20 diopters by adding a lens inside the eye and removing no tissue. Very low prescriptions are treated with LASIK or PRK rather than SMILE, whose lenticule becomes too thin to be predictable.

Then the cornea

Corneal thickness and shape decide whether a laser can be used at all and which one. A thick, regular cornea suits any of the three laser procedures. A thinner regular cornea points to PRK or SMILE, which preserve more tissue than a LASIK flap. A cornea with any sign of keratoconus generally rules out laser vision correction; in carefully selected cases, after physician evaluation, the ICL may be considered instead. These measurements cannot be guessed; they are the reason the consultation is 90 minutes long.

Then your tear film and your life

A few practical questions finish the picture:

• Dry eye: LASIK typically causes the most temporary dryness, SMILE usually less, and the ICL almost none; dry eye is usually temporary, and your surgeon reviews your risk. Established dry eye pushes toward SMILE or the ICL
• Impact risk: contact sports, martial arts, law enforcement and military service favor a flapless procedure, so PRK, SMILE or the ICL over LASIK
• Recovery time: if you need to be back at work in a day, LASIK, SMILE and the ICL deliver that; PRK needs a week
• Reversibility: only the ICL can be removed if your needs change

The five procedures at a glance

• LASIK: femtosecond flap plus excimer reshaping. Next-day recovery. Treats nearsightedness, farsightedness and astigmatism. Needs adequate corneal thickness
• PRK: surface excimer reshaping, no flap. A week to be comfortable, weeks to sharpen. Best for thin or irregular corneas and impact risk
• SMILE: lenticule removed through a small incision, no flap. One to two day recovery, less dry eye. Nearsightedness and astigmatism only
• EVO ICL: a lens placed inside the eye, nothing removed, removable. Next-day recovery. High prescriptions, thin corneas, dry eye; approved for ages 21 to 45
• Refractive Lens Exchange: the natural lens replaced with a multifocal, extended depth of focus or toric lens. Over 45; distance and reading; no future cataract, though the lens capsule can cloud later and is treated with a quick laser

Why the recommendation here is independent

Practices that offer one or two of these procedures tend to recommend the ones they offer. Because all five are performed here by Dr. Bavand Youssefzadeh, a fellowship-trained cornea and refractive surgeon, the consultation can follow your measurements to whichever answer fits, and tell you plainly when the answer is to wait or to do nothing. The two minute self test on this site gives a first indication; the consultation gives the answer.