EVO ICL vs. LASIK & PRK
November 17, 2023
As a refractive surgeon, I have had the great privilege and pleasure to help tens of thousands of people get out of their glasses and contact lenses. Over the past 25 years, we have developed better and better technology. We also have much more experience in seeing the outcomes, whether they be amazingly life-changing (which they almost always are) or sub-optimal, for whatever reason.
Eye Dryness
One of the biggest issues that we have after the LASIK or PRK procedures (collectively called “laser vision correction”) is that the surface of the eye is healing for weeks to months. Usually there are no symptoms, but when someone has dryness it can present as foggy, especially in the mornings and generally gets better throughout the day. It does get better but sometimes takes additional therapy such as ointment, prescription drops, eyelid rejuvenation treatment and others. Generally dryness is worse in women than men by a factor of about 20:1. It’s also worse as we get older and we produce fewer tears. The reason for women having more dryness than men is typically attributed to female hormones versus male hormones. For women, production of natural tears drops significantly at the time of menopause, which is an average age of 51 years old. There’s a complex interaction of the surface of the eye between the volume of tears produced and the oil (fat) on the surface of the eye, which is protective. When we produce less of our own tears, and the normal oil glands on the margin of our eyelids become progressively dysfunctional, the surface of the eyes can suffer, which can result in foggy vision, burning, watering, and/or redness.
I have always thought that if we could just get rid of the temporary dryness, there would be even fewer negative side effects, however temporary, and make the patient happier and their overall experience better. Now I believe we may have that solution for many patients who would like to have clear, uncorrected vision but without the potential for even temporary dryness with concomitant foggy vision. That solution is the EVO ICL (implantable contact lens). Don’t get me wrong: LASIK and PRK are great time-tested procedures that have been performed on tens of millions of people and changed countless lives for the better, but for those who need to use artificial tears or other treatments for dryness, EVO ICL is a game-changer.
EVO ICL
The EVO ICL is a tiny custom artificial lens that can be inserted inside the eye in an utterly painless, five minute procedure that will be invisible to the patient, and (sometimes) even the eye doctor. The EVO ICL procedure takes about five minutes per eye vs. 3 minutes per eye with LASIK and PRK. EVO ICL is painless during and after the procedure whereas LASIK tends to have about 4 to 6 hours of irritation and watery eyes, and PRK has about two days of irritation. EVO ICL has typically no irritation afterwards. There is no change to the surface of the eyes, so other than perhaps some slight annoyance from the medicated drops that we have our patients use for a week postoperatively, there is no post-operative dryness experienced by the patient. Additional positive attributes of the EVO lens is that it does not remove any tissue from the eye. Typically this is not a big deal for LASIK and PRK patients, but it can be, especially in the higher ranges of prescription.
With EVO ICL, there is no flap. With LASIK, there is an extremely small risk of the flap moving in the first few months if a patient gets poked in the eye with a finger or something else. This has some increased risk for several months after the LASIK procedure, but EVO ICL has zero risk of this complication.
EVO ICL is accurate at all ranges of prescription (up to -15.0, which is an extreme amount of nearsightedness. It also can treat up to 4 diopters of astigmatism which would cover 99% of people.) LASIK is very accurate in the lower ranges of prescription, but at the higher ranges of prescription (above -6.00 dpt of nearsightedness), the risk of needing an enhancement goes up to about 5%, whereas in the low ranges it’s less than 1%.
Enhancements
Another positive attribute of the EVO ICL lens is that it is stable over long periods of time. With LASIK there is a small percentage of people that present many years after their original procedure and need a touchup. We call this touchup and “enhancement.” When I worked for a large corporate LASIK provider, we looked at the number of people who were coming back and needing an enhancement after LASIK and PRK. In about 125,000 eyes treated over a 10 year period from the year 2000 to 2010, about 1% per year of people who had had LASIK were coming back and needing a touchup. It’s typically a small amount of additional laser, but we’d still prefer if it was 100% perfect for life.
So far (8 years) with the EVO ICL procedure, we have not seen this. We have not treated as many patients with the EVO as we have with LASIK, nor for as many years, but I would expect at least a few patients to have come back after performing the ICL procedure for over eight years if the need for enhancement was similar to LASIK. We have not yet seen patients needing an enhancement. If an enhancement is ever required, we would recommend that we do laser touchup rather than replacing the lens in the eye.
New Technology: Risk vs. Benefit
Another potential advantage, although a small one, is that after LASIK, the calculation of intraocular lens powers for cataract surgery can be erroneous due to the flattening of the cornea. With the EVO ICL, the calculations are as accurate as if you had not had the procedure. However this will likely not be a big deal over the coming decades because there are already “light adjustable lenses,” called LAL, whereby surgeons can adjust the lens power without doing a lens exchange or any laser.
We at SharpeVision embrace new technology only after we have collectively had great experience with it over several years. We are conservative, but in my opinion, not overly so. We are always assessing and evaluating technologies that bring the right combination of efficacy and safety, and that improve on existing technology. Safety is number one however. The EVO ICL is, in my opinion, just that: extremely safe and potentially even better technology in terms of patient experience, comfort, recovery time, safety, and also very importantly: visual quality.
In terms of visual quality there was a recent study* stating that for milder prescriptions, the EVO ICL was equal to LASIK in terms of vision: acuity, contrast sensitivity, and fewer aberrations. In stronger prescriptions, the EVO was significantly better than LASIK in all the above categories.
We are also making the experience better at SharpeVision in collaboration with Staar Surgical, the manufacturer of the EVO ICL. We have a consignment of all the possible lens combinations, so that we can perform the surgery without waiting for the lens to be shipped or made if they don’t have it in stock. This will allow the patient experience to be similar to LASIK and significantly better than PRK. We are breaking barriers at SharpeVision! We are making glasses a thing of the past! Our mission is to allow anyone of any age and any prescription to live a life with clear, uncorrected vision. Please schedule your free vision correction exam to see if you are candidate for any of our procedures.
* Journal of Cataract & Refractive Surgery 48(10):p 1204-1210, October 2022.