ICL surgery can provide long-term correction of myopia while preserving the natural crystalline lens of the eye. However, because the Implantable Collamer Lens is placed inside the eye close to the natural lens, cataract formation is a recognized potential complication.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
The risk is an important consideration before ICL surgery, but it should also be understood in context. Modern ICL designs have improved the safety profile of the procedure, and cataract does not develop in every patient. If you are considering ICL surgery, you can learn more about the procedure and its suitability on our ICL treatment page.
What Is a Cataract?
A cataract occurs when the eye's natural crystalline lens becomes cloudy. The natural lens normally helps focus light onto the retina, allowing you to see clearly. As it becomes cloudy, light does not pass through it normally and vision can become blurred or hazy.
Cataracts can develop naturally with age, but certain factors can cause them to develop earlier. Therefore, if a person develops a cataract after ICL surgery, it does not automatically mean that the ICL itself was the only cause.
Can ICL Surgery Cause Cataracts?
Yes. Cataract formation is a recognized potential complication following ICL implantation. The ICL is positioned behind the iris and in front of the natural crystalline lens.
Although the implant is designed to maintain an appropriate separation from the natural lens, the relationship between the two structures can vary according to individual eye anatomy and the positioning of the ICL.
Earlier ICL designs were associated with a greater concern about anterior subcapsular cataract formation. Modern central-port ICL designs have improved the way fluid moves through the eye and have been associated with lower reported rates of cataract formation than earlier designs. However, the risk has not been eliminated.
Why Can Cataracts Develop After ICL Surgery?
The exact mechanism can vary. Several factors may contribute to cataract formation after ICL implantation.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Interaction With the Natural Lens
The ICL sits close to the natural crystalline lens. If the relationship between the two lenses is not optimal, mechanical or other effects on the natural lens may contribute to lens opacity.
Low ICL Vault
Vault refers to the space between the back surface of the ICL and the front surface of the natural crystalline lens. A very low vault means that the ICL sits relatively close to the natural lens.
Historically, low vault has been associated with a higher risk of anterior subcapsular cataract formation. This is one reason postoperative assessment of ICL position and vault is important.
Age
Age is another important consideration. The natural crystalline lens changes as you get older, and the risk of developing cataract naturally increases with age.
Therefore, an older patient undergoing ICL surgery may have a different long-term cataract risk from a younger patient, even when the ICL itself is appropriately positioned.
High Myopia
Higher degrees of myopia have also been associated with an increased risk of cataract after ICL implantation. The underlying reasons are complex, because high myopia itself can be associated with structural changes in the eye.
This means that cataract risk should be considered together with the patient's age, degree of myopia, eye anatomy, and other individual factors rather than attributed to the ICL alone.
How Common Is Cataract After ICL?
The reported rate depends on the ICL generation, patient population, follow-up period, and definition of cataract used in a particular study.
Earlier studies of posterior chamber phakic ICLs reported higher cataract rates. More recent evidence involving central-port ICLs has generally found cataract formation to be uncommon, particularly during shorter-term follow-up.
However, the FDA continues to identify cataract as a potential long-term risk and notes that the risk of visually significant cataract may increase with each year of follow-up. The FDA also states that long-term risk beyond the available follow-up period remains uncertain.
This is why it is more useful to think of cataract as an important long-term possibility that requires monitoring, rather than assuming that cataract will occur after ICL surgery.
Does Every Cataract After ICL Affect Vision?
No. A lens opacity does not necessarily mean that a person immediately develops significant visual impairment. A small or early cataract may cause few noticeable symptoms and may simply be monitored.
If the opacity progresses and begins to interfere with everyday vision, it may become a visually significant cataract.
Symptoms can include:
- Blurred or cloudy vision
- Reduced contrast or visual clarity
- Increased sensitivity to light
- Glare around lights
- Difficulty seeing clearly at night
- Frequent changes in glasses prescription
- Colours appearing less vivid
What Is an Anterior Subcapsular Cataract?
One type of lens opacity that has been associated with ICL implantation is an anterior subcapsular cataract. This opacity develops toward the front portion of the natural crystalline lens, underneath its capsule.
It can occur in association with factors affecting the relationship between the implanted ICL and the natural lens. The presence of an anterior subcapsular opacity does not automatically mean that vision will be significantly affected. Its clinical importance depends on its size, location, progression, and effect on visual function.
When Can a Cataract Develop After ICL?
Cataract formation can occur at different points after ICL implantation. Some cases may become apparent relatively early, while others develop several years after surgery.
The FDA notes that the risk of cataract continues to increase with each year after ICL implantation and that long-term risk beyond the available study period is not fully established.
This is one reason that follow-up should not be viewed as something that is needed only during the first few weeks after surgery.
Does the ICL Need to Be Removed If a Cataract Develops?
Not necessarily in every situation, but if cataract surgery becomes necessary, the existing ICL generally needs to be considered as part of the surgical plan.
During cataract surgery, the cloudy natural lens is removed and replaced with an appropriate intraocular lens. Because the ICL occupies space in front of the natural lens, the surgeon may need to remove the ICL before or as part of the cataract procedure.
The exact surgical approach depends on the patient's eye anatomy, the position of the ICL, the condition of the natural lens, and the surgeon's assessment.
What Happens If a Cataract Develops After ICL?
The approach depends on how much the cataract is affecting vision.
Early or Mild Cataract
If the cataract is small and does not significantly interfere with vision, immediate surgery may not be necessary. The ophthalmologist may monitor the lens during regular eye examinations.
Visually Significant Cataract
If the cataract begins to interfere with daily activities or causes significant visual symptoms, cataract surgery may be recommended.
The ICL may need to be removed, and the natural cloudy lens is replaced with an intraocular lens selected according to the patient's visual needs and eye measurements.
Can Cataract Risk After ICL Be Reduced?
The risk cannot be eliminated completely, but careful patient selection, appropriate lens sizing, accurate positioning, and long-term monitoring are important.
Before surgery, the ophthalmologist assesses the anatomy of the eye and other factors that influence ICL selection. After implantation, the lens position and vault can be assessed during follow-up.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Appropriate surgical technique is also important. The FDA's ICL labeling emphasizes complete removal of ophthalmic viscosurgical material used during surgery, because retained material has been associated with an increased risk of cataract formation.
Does the Type of ICL Affect Cataract Risk?
ICL design has evolved over time. Earlier models and modern central-port models do not have identical designs or reported safety profiles.
The central port in modern EVO/EVO+ ICLs allows aqueous fluid to pass through the lens without requiring a separate peripheral iridotomy in the same way as older non-port designs. Modern studies have reported low rates of cataract formation, while longer-term monitoring remains important.
Therefore, cataract risk should always be discussed in relation to the specific ICL model, patient characteristics, and available follow-up data, rather than applying an older complication rate to every modern ICL procedure.
What Symptoms Could Indicate a Cataract?
Cataract symptoms can develop gradually, so you may not notice a sudden change. Possible symptoms include:
- Progressively blurred or cloudy vision
- Increasing difficulty seeing at night
- More glare from headlights or bright lights
- Halos around lights
- Reduced contrast
- Colours appearing faded
- A prescription that seems to change repeatedly
These symptoms are not specific to cataract. Similar visual changes can occur for other reasons, so an eye examination is needed to determine the underlying cause.
Can Cataract After ICL Be Treated?
Yes. If a cataract becomes visually significant, it can generally be treated with cataract surgery. Cataract surgery involves removing the cloudy natural lens and replacing it with an artificial intraocular lens.
In an eye that previously had an ICL, the ophthalmologist must take the existing implant into account when planning the procedure.
The fact that cataract can be treated does not mean that the risk should be ignored. Careful monitoring remains important so that any change in the natural lens can be evaluated at the appropriate time.
The Bottom Line
Cataract formation is a recognized potential long-term complication of ICL surgery, but it does not occur in every patient. Modern central-port ICL designs have been associated with lower reported cataract rates than earlier lens designs, while factors such as age, high myopia, low vault, lens positioning, and duration of follow-up can influence individual risk.
A cataract may initially be small and cause little or no visual impairment. If it becomes visually significant, it can generally be treated with cataract surgery, although the existing ICL may need to be removed as part of the surgical plan.
For this reason, ICL care does not end when the initial recovery is complete. Regular eye examinations help monitor the natural lens, ICL position, eye pressure, and overall eye health, allowing any changes to be identified and managed appropriately.
