ICL surgery is a widely used option for correcting moderate to high myopia, with toric ICLs also used for certain types of astigmatism. The procedure involves placing a lens inside the eye while leaving the natural crystalline lens in place.
If you are considering the procedure, understanding the potential risks is an important part of making an informed decision. You can learn more about the procedure and its suitability on our ICL treatment page.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Like any intraocular procedure, ICL surgery is not completely risk-free. Many patients experience a smooth recovery, but complications can occur during the early postoperative period or, less commonly, later. The likelihood and type of complication can depend on factors such as eye anatomy, lens selection, the degree of refractive error, and individual healing.
What Are the Common Effects After ICL Surgery?
Not every symptom after surgery means that a complication has occurred. Some temporary changes can occur as the eye recovers from the procedure.
These may include:
- Mild eye discomfort or irritation
- Watering of the eye
- Light sensitivity
- Temporary blurred vision
- Mild redness
- A foreign-body sensation
- Temporary fluctuations in vision
These symptoms generally improve as the eye heals. However, persistent, worsening, or unexpected symptoms should be assessed by an ophthalmologist rather than assumed to be part of normal recovery.
Can ICL Surgery Cause Increased Eye Pressure?
Increased intraocular pressure (IOP) is one of the complications that can occur after ICL implantation. Eye pressure may rise for different reasons, including postoperative inflammation or other changes affecting the drainage of fluid within the eye.
In some situations, an ICL that creates excessive vault can contribute to narrowing of the angle between the iris and cornea, which can affect fluid drainage.
Because significantly elevated eye pressure can damage the optic nerve, pressure is checked during postoperative follow-up. If an abnormal increase is detected, treatment may be needed to bring the pressure back into a safer range.
Can ICL Cause Cataracts?
Cataract formation is a recognized potential long-term complication of ICL implantation. A cataract develops when the natural crystalline lens becomes cloudy. Because an ICL sits close to the natural lens, there is a potential risk of lens changes after implantation.
The risk can vary according to the ICL design, patient age, degree of myopia, lens positioning, and other individual factors. Modern ICL designs have been developed to reduce contact with the natural lens, but the possibility of cataract formation cannot be completely eliminated.
Regular eye examinations allow the natural lens to be monitored over time. If a visually significant cataract eventually develops, cataract surgery may be considered according to the patient's circumstances.
Can the ICL Damage the Cornea?
The cornea contains endothelial cells that help maintain its clarity by regulating fluid within the corneal tissue. These cells do not normally regenerate significantly, so long-term endothelial health is an important consideration with any intraocular lens.
ICL implantation can be associated with endothelial cell loss. Significant loss over time can potentially affect corneal clarity and, in severe cases, lead to corneal decompensation.
This is why preoperative assessment of endothelial cell density and periodic monitoring after implantation are important, particularly for patients who retain the lens for many years.
Can the ICL Move or Rotate?
The ICL is designed to remain in a stable position inside the eye, but displacement or rotation can occur. A change in lens position may affect the intended optical correction or the relationship between the ICL and surrounding eye structures.
For a standard ICL, displacement may result in decentration or other positional changes. With a Toric ICL, rotation is particularly important because the lens needs to maintain the planned axis to provide the intended astigmatism correction.
If significant rotation, decentration, or displacement occurs, the ophthalmologist may monitor the lens or consider repositioning or replacement when clinically necessary.
What Is ICL Vault and What Happens If It Is Too High or Too Low?
Vault describes the distance between the implanted ICL and the natural crystalline lens. An appropriate relationship between the ICL and the natural lens is important. If the vault is unusually high or low, the surgeon may need to assess the lens position and its effect on surrounding structures.
An excessively high vault can contribute to narrowing of the anterior chamber angle and may increase the risk of elevated eye pressure. A very low vault may increase the concern for contact between the ICL and the natural lens.
Postoperative examinations can help identify these positional issues and determine whether observation or further treatment is appropriate.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Can ICL Surgery Cause Glare or Halos?
Some patients may notice glare, halos, or other unwanted visual phenomena after ICL implantation, particularly in low-light conditions.
These symptoms can be influenced by factors such as pupil size, the optical characteristics of the implanted lens, residual refractive error, and individual visual perception.
For some patients, these effects may become less noticeable with time. However, persistent or troublesome visual symptoms should be discussed during follow-up.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Can ICL Surgery Cause Inflammation?
Because ICL implantation involves surgery inside the eye, inflammation can occur after the procedure. Mild postoperative inflammation may be part of the normal healing response and is generally managed with prescribed medication.
More significant or persistent inflammation requires medical assessment because prolonged inflammation can affect other structures inside the eye.
Rarely, serious intraocular infection can occur after eye surgery. Although uncommon, this is a potentially sight-threatening complication that requires urgent treatment.
Can ICL Surgery Affect Vision Permanently?
Most patients undergo ICL surgery with the goal of improving their uncorrected vision, but a completely predictable result cannot be guaranteed. Possible visual problems include:
- Residual or undercorrected prescription
- Overcorrection
- Blurred vision
- Glare or halos
- Changes in visual quality
- Loss of best-corrected visual acuity in uncommon cases
The risk of complications and reduced visual outcomes may be higher in eyes with very high levels of myopia or other significant ocular characteristics. This is one reason detailed preoperative assessment is essential before deciding on ICL implantation.
When Might an ICL Need to Be Repositioned, Exchanged, or Removed?
Although ICLs are intended for long-term implantation, an additional procedure may occasionally be required. This may be considered if the lens:
- Is significantly displaced or decentered
- Rotates enough to affect Toric ICL correction
- Has an inappropriate vault
- Contributes to persistent or significant eye pressure problems
- Is associated with other complications affecting the eye
- Needs to be replaced for another clinically appropriate reason
Whether an ICL should be repositioned, exchanged, or removed depends on the specific problem and the overall condition of the eye.
Who May Have a Higher Risk of Complications?
Risk is not identical for every patient. Certain characteristics may influence the likelihood of complications or affect the surgical outcome. These can include:
- Very high levels of myopia or myopic astigmatism
- Inadequate anterior chamber depth
- Unsuitable anterior chamber angle anatomy
- Low endothelial cell density
- Existing eye disease
- Age-related changes in the natural lens
- Inappropriate ICL sizing or positioning
How Can the Risk of ICL Complications Be Reduced?
Complications cannot be eliminated completely, but careful planning can help reduce avoidable risks.
Detailed Preoperative Assessment
Measurements of the eye's anatomy, prescription, anterior chamber, endothelial cells, and other structures help determine whether ICL surgery is appropriate.
Correct Lens Selection
The appropriate ICL size and power are important for achieving the intended optical correction and maintaining a suitable position inside the eye.
Following Postoperative Instructions
Using prescribed medications correctly, avoiding activities restricted by your surgeon, and attending scheduled follow-up examinations all contribute to safe recovery.
Long-Term Monitoring
ICL follow-up does not necessarily end once the initial recovery is complete. Periodic eye examinations can help monitor eye pressure, the ICL position, the natural lens, corneal endothelial health, and overall eye health.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
The Bottom Line
ICL surgery can provide effective vision correction, but it is an intraocular procedure and therefore carries potential risks. Temporary discomfort, blurred vision, light sensitivity, and other short-term effects can occur during recovery, while less common complications can involve eye pressure, inflammation, cataract formation, corneal endothelial health, lens positioning, or retinal health.
Careful preoperative assessment, appropriate ICL selection, correct surgical positioning, and regular follow-up are important for identifying and managing these risks. Understanding the possible complications can help you have a more informed discussion with your ophthalmologist about whether ICL surgery is appropriate for your eyes.
