LASIK vs. ICL: which one is right for you?

ICL and LASIK are both modern vision correction techniques that can help an individual correct refractive errors and see without glasses or contact lenses. The differences between the two are in the medium used to perform the correction. LASIK performs a correction by changing the contour of the cornea. ICL is an intraocular procedure that corrects the vision through a lens implant that refocuses the light. LASIK alters the anatomical structure to support refocusing the vision, while ICL is an additive procedure, leaving the anatomy largely unaltered.

Both procedures are FDA-approved and considered safe. Satisfaction rates for both procedures are high. The answer to which one is right for you depends on where you sit within the three categories below:

1. Anatomical suitability
2. Side effect tolerance
3. Future considerations

Anatomical Suitability

Suitability varies by individual based on their physical anatomy and the prescription being corrected. In the United States, LASIK is approved to treat prescriptions from +6.00 to -12.00 diopters, while ICL in the United States is approved to treat an effective prescription from -2.75¹ to -16 spherical equivalent diopters. Regarding astigmatism, LASIK can treat up to 6 D of cylinder. ICL can treat up to 4 D of cylinder.

¹A -3.00 D ICL lens produces approximately a -2.75 D correction.

As you can tell, LASIK can treat a wider range of prescriptions, including hyperopia. However, even though the approval range is wide, I do not typically recommend treating to the full limits. For corneal-based procedures, like LASIK, efficacy falls and side effects rise as you approach the limits, and ICL doesn't behave that way because it's an implant. These differences are less noticeable when the prescription is low, and more relevant when your prescription sits in the upper single-digit range and above.

What ICL requires in terms of anatomy is adequate space within the eyes to accommodate the implant. Measurement values, such as anterior chamber depth, iridocorneal angle, and corneal white-to-white measurements, are assessed to determine proper fit.

Corneal thickness, or pachymetry, is a key criterion for LASIK eligibility regarding how much prescription will be treated. The higher the prescription, the more corneal thickness would need to be present for LASIK.

Side Effect Tolerance

Both procedures involve the eye, which can have sensitivity regardless of which procedure is performed. The cornea is a sensitive area of the body, which can respond well and heal quickly from the LASIK procedure. However, a high diopter treatment would require significant flattening of the corneal contour, which can lead to more glare and halos and decreased vision quality, particularly at night. Dry eye sensitivity can also limit LASIK suitability, as the corneal nerve that causes the sensitivity can be irritated by the procedure. The recovery can be affected by ongoing or pre-existing ocular surface conditions. Most individuals recover from these limited side effects.

ICL does not require significant corneal alteration, thereby making it more suitable for those with chronic ocular surface sensitivity. However, being an intraocular procedure, special attention needs to be paid to the intraocular pressure, corneal endothelial cell health, and the natural crystalline lens. Long-term stability of vision and the eye after ICL is determined by monitoring the fit post-operatively. Commonly, ICL is known to produce halo-like light disturbances at night or in dim lighting. Most individuals adapt to these halos within a few weeks.

Future considerations

The changes to the cornea are permanent and would need to be considered in the future when considering another vision enhancement procedure or lens replacement. Lens replacement calculation would need to take into consideration the altered corneal contour to get the accurate IOL power selection. ICL, on the other hand, is a removable and exchangeable procedure that can be performed as needed. Since the cornea has not been altered, standard IOL calculations apply.

For a quick general guideline:

• Thin cornea relative to prescription points to ICL.
• Hyperopia² and low myopia (-0.50 to -2.75) point to LASIK (or other non-ICL procedures).
• Upper single digits and above in myopic prescriptions shift toward ICL.
• Dry eye sensitivity points to ICL.
• Shallow chamber or narrow angle points to LASIK.
• Anyone planning around future lens replacement should factor in the corneal alteration.

²A hyperopic ICL exists but is not approved in the US.

Both LASIK and ICL are efficacious procedures and have a high level of satisfaction with accurate outcomes. As a practitioner of LASIK’s latest Wavelight Plus technology and a faculty member of the STAAR Surgical EVO Masters Program, I offer each procedure in my refractive practice, since they cover a different range of prescriptions. The only way to determine which procedure is right for you is to find a surgeon familiar with both procedures and go through a detailed evaluation.