Dr. Robert Dinga

When it comes to addressing your vision issues, making an informed decision that best suits your needs and eye health is crucial. You may have come across a relatively recent eye surgery known as EVO ICL, which serves as an alternative to LASIK. In this article, we will provide a clear definition of both procedures and dissect their distinctions to empower you in making the optimal choice for your vision. 

What is EVO ICL? 

EVO ICL surgery represents a form of refractive surgery that can be likened to the introduction of specialized permanent “contact” lenses into your eyes. These lenses, referred to as Implantable Collamer Lenses (ICL), possess dimensions that are thinner and smaller compared to typical contact lenses. A skilled ophthalmologist implants this lens within the interior of the eye, typically behind your iris and in front of your eye’s natural lens. Within the core of the ICL lens lies a perforation designed to facilitate fluid circulation around the lens and iris. Notably, this ICL lens is permanent and does not necessitate removal or cleaning akin to regular contact lenses. 


In contrast to EVO ICL surgery, which entails an incision in the eye for lens placement, LASIK operates entirely on the cornea, the transparent, front part of the eye. LASIK achieves vision correction by reshaping the cornea, altering its curvature to provide improved vision. Before commencing the LASIK procedure, numbing drops with anesthetic properties are applied to your eyes. Once your eyes are fully anesthetized, a LASIK surgeon employs a laser to create a thin, hinged corneal flap, which is then gently folded back to expose the cornea. Subsequently, a computer-controlled laser emits controlled pulses of light to reshape the cornea, customizing the correction to your individual visual needs. The corneal flap is repositioned over the cornea and healing begins immediately. The flap adheres through natural suction, eliminating the need for sutures. The precise lasers employed during LASIK procedures reshape the cornea to rectify the patient’s vision. 

Risks Associated with EVO ICL 

STAAR Surgical, a leading manufacturer of ICL implants, reports the following risks associated with EVO ICL lenses: 

  1. Additional (Secondary) Surgery: EVO ICL surgery, while generally successful, may necessitate additional surgeries in some cases. These secondary procedures might be required to remove, replace, or adjust the position of the EVO ICL lens. Furthermore, additional surgery may be recommended if you develop complications such as cataracts or increased pressure inside your eye. 
  2. Raised Intraocular Pressure (IOP) and Glaucoma Development: Normal intraocular pressure (IOP), which measures the pressure inside the eye, typically falls within a range of 10-21 millimeters of mercury (mmHg). When IOP exceeds this normal range,  it is termed ocular hypertension, which, if left untreated, can lead to optic nerve damage, a condition known as glaucoma. Patients with high levels of nearsightedness are at an increased risk of developing glaucoma. 
  3. Cataract Formation: Cataracts are characterized by the clouding of the natural crystalline lens within the eye, leading to decreased vision. EVO ICL lenses are implanted inside the eye, near the crystalline lens, which poses a risk of cataract development. Factors such as older age and higher levels of nearsightedness prior to surgery can further elevate the likelihood of cataracts. This risk continues to rise with each year that the EVO ICL lens remains in the eye. Cataracts affecting vision may necessitate surgical removal. Consequently, it is essential to maintain regular eye exams to monitor for cataract development. The long-term risk of cataracts beyond seven years post-EVO ICL surgery remains unknown. In cases where cataract surgery is recommended, both the ICL lens and the cataract are removed, followed by the implantation of another intraocular lens, mirroring the routine cataract surgery procedure. 
  4. Loss of Best Corrected Vision: Post-surgery, there is a possibility that your vision may deteriorate. This decline can manifest as a loss of two or more lines on an eye chart, emphasizing the importance of cautious consideration and assessment of potential outcomes. 
  5. Endothelial Cell Loss: The cornea, the eye’s outermost layer, relies on a thin, single layer of cells called endothelial cells to maintain clarity by regulating water levels. As individuals age, these cells naturally decrease in number. However, additional loss beyond the typical age-related decline can occur following various eye surgeries, including EVO ICL. Excessive endothelial cell loss may result in corneal cloudiness and reduced vision. Before undergoing EVO ICL surgery, a comprehensive eye exam is conducted to evaluate whether you are a suitable candidate. Patients receiving the EVO ICL lens may experience a degree of endothelial cell loss, which, over time, may surpass what is expected with aging. Depending on the extent of this loss, it can lead to fluid accumulation or corneal swelling, a condition known as corneal edema. In severe cases, corneal transplantation may be required. 
  6. Glare and Halos: Glare and halos, visual phenomena characterized by the perception of bright, scattered light, may become more pronounced following EVO ICL surgery. These effects are particularly noticeable in low-light conditions when the pupil is dilated. It is worth noting that even individuals who did not experience glare and halos before the surgery may develop them post-surgery. For those currently dealing with glare and halos, there is a possibility that these visual disturbances may intensify after EVO ICL surgery. 
  7. Additional Risks: Beyond the aforementioned risks, STAAR Surgical also notes that EVO ICL surgery may be associated with additional potential complications, including: 
    • Movement of the colored portion of the eye (iris) through a surgical wound to a position outside the eye (iris prolapse). 
    • Bleeding in the area of the retina responsible for reading vision (macular hemorrhage). 
    • Bleeding beneath the retina (subretinal hemorrhage). 
    • Increase in focusing error (astigmatism). 
    • Lifting or pulling of the retina from its natural position (retinal detachment). 
    • Inability of fluid to flow from the back chamber of the eye to the front chamber, frequently blocking drainage and raising eye pressure (pupillary block glaucoma). 
    • Unequal pupil size (anisocoria). 
    • Abnormal release of pigment particles from cells in the eye that could block fluid drainage from inside to outside the eye (pigment dispersion). 
    • Scar tissue formation at the outer edges of the front chamber of the eye (peripheral anterior synechiae). 

EVO ICL surgery offers significant benefits in terms of vision correction, but it is important to be aware of the associated risks. Patients considering this procedure should engage in thorough discussions with their eye care professionals to make informed decisions about their eye health. Regular post-operative check-ups are vital for monitoring potential complications and addressing them promptly, ensuring the best possible visual outcomes after EVO ICL surgery. 

Similarly, LASIK offers significant benefits in terms of vision correction, but like all medical procedures, also presents its own set of associated risks. These may include dry eyes, glare, halos, and the potential need for enhancement surgeries. To determine the most suitable treatment for your specific needs, you can begin with a LASIK consultation conducted by a professional specializing in LASIK. 

At TLC Laser Eye Centers, we provide complimentary consultations to assess your candidacy for LASIK. If you are eligible, we are delighted to offer you the opportunity to undergo traditional LASIK, granting you the gift of improved vision. However, if LASIK is not a viable option for you, our medical team can discuss alternative approaches, which may include EVO ICL, tailored to your unique situation. 

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