ICL in Keratoconus: When It Helps, When It Doesn’t, and How Doctors Decide

Keratoconus is a condition in which the cornea gradually thins and becomes irregularly shaped, leading to blurred or distorted vision. Many patients struggle to achieve satisfactory vision with glasses and are often told that laser vision correction procedures, like LASIK or SMILE, are not suitable.

In recent years, Implantable Collamer Lenses (ICL) have become an option for certain patients with keratoconus. However, it is important to understand that ICL does not treat keratoconus itself and is not suitable for every patient.

This post explains when ICL may be considered, when it should be avoided, and how doctors make the decision, so patients can have informed discussions with their ophthalmologist.

What problem does ICL solve?

ICL is a lens implanted inside the eye, in front of the natural lens. It corrects refractive error—myopia, hyperopia, or astigmatism—by improving how light focuses on the retina.

It is important to note:

• ICL does not strengthen or reshape the cornea

• ICL does not stop keratoconus progression

• ICL cannot correct the irregularity of the cornea

What it can do, in selected cases, is improve vision to the level achievable with glasses, bypassing some of the refractive error caused by keratoconus.

Why ICL is different from laser vision correction

Laser procedures reshape the cornea. In keratoconus, where the cornea is already weak and irregular, this can worsen the condition. For this reason, laser correction is usually not recommended.

ICL, on the other hand:

• Does not remove corneal tissue

• Does not alter corneal biomechanics

• Works inside the eye, bypassing corneal irregularity

This is why ICL may be discussed in selected keratoconus patients—but only under careful evaluation.

When can ICL be considered in keratoconus?

ICL may be considered only in carefully selected cases. Several factors are evaluated:

• Stable keratoconus

  
  

  The cornea should be stable, often confirmed after corneal cross-linking (CXL).

• Reasonable spectacle-corrected vision

  
  

  ICL can improve vision to the level achieved with glasses. It does not replicate vision achieved with rigid or scleral contact lenses, so patients whose best vision is only achievable with these lenses may not benefit fully.

• No recent progression

  
  

  Implanting an ICL in actively progressing keratoconus is generally avoided.

• Realistic expectations

  
  

  Patients should understand that ICL improves refractive error but does not regularise the cornea, and perfect vision cannot be guaranteed.

When is ICL not advisable?

ICL is usually not recommended when:

• Keratoconus is actively progressing

• Corneal irregularity is severe

• Vision is poor even with glasses

• There is significant corneal scarring

• Expectations are unrealistic (e.g., expecting a cure for keratoconus)

In such situations, ICL will not address the primary cause of reduced vision and may lead to disappointment.

How ICL compares with contact lenses in keratoconus

Specialty contact lenses (rigid gas permeable, hybrid, or scleral) remain the mainstay for visual rehabilitation.

Compared to lenses:

• Contact lenses can neutralise corneal irregularity

• ICL cannot correct irregular astigmatism

• Some patients may still require contact lenses even after ICL

ICL is therefore not a replacement for contact lenses in many patients, but it may reduce dependence on them in selected individuals.

Does ICL prevent the need for keratoplasty?

No. ICL does not prevent progression, nor does it replace corneal transplantation if that becomes necessary.

In advanced keratoconus with significant scarring or poor vision, keratoplasty (DALK or full-thickness transplant) remains the definitive treatment. ICL is considered only when transplantation is not indicated and the cornea is stable.

Common questions patients ask

Will keratoconus worsen after ICL?

ICL does not worsen keratoconus, but it also does not prevent progression. Stability must be confirmed before surgery.

Is ICL permanent?

ICL is intended as a long-term refractive solution, but it can be removed if necessary.

Will I still need glasses or lenses?

Possibly. Many patients still require glasses or contact lenses for optimal vision.

Key takeaway

ICL in keratoconus is not about eligibility, but about appropriateness. It may help:

• Stable disease

• Carefully selected eyes

• Patients with realistic expectations

A detailed corneal evaluation and open discussion with your ophthalmologist are essential before considering ICL.