EVO ICL: Indications, Patient Selection, and Surgical Tips

Globally, the annual refractive surgery volume is in the millions.¹ In 2025, there will be an estimated generation of $10.3 billion in total patient fees globally, representing a rise from $6.5 billion in 2019—that’s a compounded growth rate of 9.5%.²

A recent Market Scope report suggested that, from 2020 to 2025, the number was expected to grow at a compound annual rate of 9.6%, with surgical yearly volume increasing from 3.6 million to 5.8 million procedures.³ As surgical options continue to expand and improve, nearly every type of refractive error can be addressed and there is a viable option for the majority of individuals.

The EVO Implantable Collamer Lens (ICL) represents a significant advancement in refractive surgery, providing an effective alternative for patients who are not suitable candidates for laser vision correction (LVC) procedures, such as laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK).

In addition, the EVO ICL procedure has several advantages over LVC, which is why many patients choose to proceed with this procedure despite being great candidates for LVC.

This article explores the indications for EVO ICL, patient selection, and essential surgical tips for achieving optimal outcomes.

Indications and contraindications for the EVO ICL

The EVO ICL was approved by the FDA in March 2022 for the correction of moderate to high myopia, with or without astigmatism.⁴

For use in patients 21 to 45 years of age, the EVO ICL is indicated for:⁴

Correction of myopia with spherical equivalent ranging from -3.0 to ≤ -15.0D (the spectacle plane)
Reduction of myopia with spherical equivalent ranging from > -15.0 to -20.0D (at the spectacle plane)
Correction of myopic astigmatism with spherical equivalent ranging from -3.0 to ≤ -15.0D (in the spectacle plane) with cylinder (spectacle plane) of 1.0 to 4.0D
Reduction of myopic astigmatism with spherical equivalent ranging from greater than -15.0 to -20.0D (in the spectacle plane) with cylinder (spectacle plane) of 1.0 to 4.0D
Individuals with an anterior chamber depth (ACD) of 3.00mm or greater, when measured from the corneal endothelium to the anterior surface of the crystalline lens, and a stable refractive history (within 0.5D for both spherical equivalence and cylinder for 1 year prior to implantation)

Of note, the ICL lens is intended for placement in the posterior chamber (ciliary sulcus) of the phakic eye. The EVO ICL family of lenses should not be used in patients with a true ACD of < 3.00mm or an anterior chamber angle less than Grade III as determined by gonioscopic examination.⁴

They are also contraindicated in patients who:⁴

Are pregnant or nursing
Are less than 21 years of age
Have moderate to severe glaucoma
Do not meet the minimum endothelial cell density (ECD)

Patient selection criteria for the EVO ICL

EVO ICL presents significant advantages over LVC in certain clinical scenarios.

As a thinner cornea is a risk factor for ectasia after LVC, patients with thin corneas are ideal candidates. Metrics such as residual stromal bed (RSB) and percent tissue altered (PTA) are used to assess this risk. For individuals whose corneas are too thin to safely undergo LVC, EVO ICL may present a safer alternative.

It is also advantageous for patients with abnormal topography, since ectatic disorders remain a feared complication of LVC. While EVO ICL is not FDA-approved specifically for keratoconus (KC) or pellucid marginal degeneration (PMD), it has been used off-label in select cases.

Importantly, in eyes that may not meet strict diagnostic criteria for ectatic disease but exhibit subtle risk factors for post-LVC ectasia—such as mild inferior steepening—EVO ICL may offer a safer alternative. Unlike LVC, EVO ICL implantation preserves corneal integrity by avoiding stromal ablation, thereby reducing the risk of biomechanical destabilization in predisposed corneas.

Maintaining ocular surface and corneal health with the EVO ICL

EVO ICL may be the preferred option in patients with ocular surface disease (OSD). While effective management of OSD is crucial for successful refractive surgery outcomes and long-term ocular health, EVO ICL exerts less impact on the ocular surface, thereby minimizing the risk of exacerbating OSD symptoms.

When preservation of corneal integrity is a key consideration, EVO ICL is very effective; as an additive procedure, EVO ICL can be removed, replaced, or adjusted if necessary, offering a reversible solution that maintains the corneal structure.

This is particularly appealing to patients concerned about irreversible corneal alterations and their potential impact on future interventions, such as intraocular lens selection and implantation during cataract surgery.

Surgical tips for optimal outcomes with the EVO ICL

While EVO ICL implantation is a safe and effective procedure, adhering to meticulous surgical techniques enhances patient outcomes.

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Surgical Video of EVO ICL Implantation

Watch this narrated surgical video of EVO ICL preparation and injection by Dr. Marvasti with pearls for successfully implanting the lens.

Pre-operative preparation

In my practice, I commonly use Alprazolam for pre-sedation, while also providing the option of monitored anesthesia care for patients requiring additional relaxation. Ensuring patient comfort throughout the procedure is crucial for achieving successful surgical outcomes.

Guidelines for sizing

Accurate sizing is pivotal in the context of this surgery, as it plays a critical role in preventing complications such as cataract formation, ICL rotation, and elevated intraocular pressure (IOP). A variety of diagnostic devices and nomograms are available to aid in the sizing process.

While no single technique or formula has demonstrated superiority over others, the following guidelines may help optimize EVO ICL size selection:

Consistently use the same diagnostic device, and monitor the vaults in your cases. This practice can provide valuable insights for adjusting sizing as you accumulate experience with EVO ICL.
If not utilizing the Orbscan II (Bausch + Lomb), consider applying the adjustment factors provided by Morgan Micheletti (accessible at iclcalc.com) for adjustments based on white-to-white (WTW) distance and ACD.⁵

In my practice, I often employ two methods for determining the optimal ICL size: the manufacturer-recommended nomogram and the Lasso formula.⁶ Generally, I also order two different ICL sizes for each procedure.

This approach is beneficial in cases where an ICL exchange may be necessary, such as in instances of excessive ICL vault that could lead to angle closure or elevated IOP, or insufficient ICL vault, which heightens the risk of cataract formation.

Despite the advancements in the EVO ICL design, which significantly reduce the risk of these vault-related complications, I still find it beneficial to have two sizes readily available to prevent any delays in care.

Surgical technique EVO ICL implantation

ICL preparation

Before loading the ICL, I conduct a thorough inspection under the microscope to ensure proper orientation. I continue to observe the ICL while engaging it with the injector and pay close attention to its positioning and footplate alignment.

This preparatory step allows me to make any necessary adjustments during the ICL injection to ensure accurate delivery into the anterior chamber. For example, if the ICL appears rotated clockwise in the injector, I am prepared to rotate my wrist counterclockwise during the insertion process.

Creating an incision

Create a precise, self-sealing corneal incision that facilitates smooth lens placement while minimizing the risk of post-surgical astigmatism. I typically position the entry point of the keratome into the anterior chamber more anteriorly compared to my cataract surgery incision.

This technique helps mitigate the risk of iris prolapse, which can occur when the ICL vault is excessively high.

Insertion of the EVO ICL

Prior to insertion, carefully evacuate a portion of the ophthalmic viscoelastic device (OVD). It is crucial to proceed methodically, paying close attention to the behavior and orientation of the ICL’s distal footplates.

Adjust your hand and wrist rotation as needed to facilitate proper insertion. If the footplates do not unfold as intended, consider withdrawing the injector, adjusting the injection angle, or reloading the ICL if needed, and attempt the insertion again.

To properly position the ICL, engage the distal segments of the footplates to enable easier manipulation and secure accurate positioning within the ciliary sulcus. To safely remove the viscoelastic, certain precautions should be taken.

Whether employing manual irrigation or an irrigation-aspiration handpiece, ensure the complete removal of the OVD, as it can easily become trapped under the ICL. Avoid vigorous injection of balanced salt solution (BSS) or aspirating OVD through the central port to mitigate the risk of cataract formation.

Post-operative care

Monitor IOP and the EVO ICL vault closely after surgery, managing any elevation in IOP with appropriate medications. Regular follow-ups are essential to ensure correct lens positioning, vault, and early detection of complications.

Conclusion

The EVO ICL is a versatile and effective treatment for patients unsuited for LVC. Understanding the indications, best practices for patient selection, and following meticulous surgical protocols ensures outstanding outcomes, paving the way for improved patient satisfaction and quality of life.

As with any surgical intervention, maintaining an open dialogue with patients, managing expectations, and offering thorough pre-operative and post-operative care are critical to achieving successful results.