What Happens During a CAIRS Procedure?

31 Aug 2026

CAIRS uses donor corneal tissue, not a synthetic implant, to reshape the cornea in keratoconus. That single difference is what sets it apart from older ring-segment procedures.

Facing any eye procedure can feel daunting when you are not sure what to expect. Understanding each stage in advance makes the whole experience far less intimidating. If you are considering CAIRS treatment in London, knowing what happens before, during and after helps you feel informed and confident about the next step.

CAIRS is an advanced surgical technique for people with keratoconus. At Optimal Vision, you get a personalised assessment to work out whether it suits your particular case. The procedure uses donor corneal tissue rather than a synthetic implant to help reshape the cornea, a biocompatible approach to managing keratoconus.

What Is CAIRS?

CAIRS stands for Corneal Allogenic Intrastromal Ring Segments, a minimally invasive procedure developed to improve corneal shape in keratoconus patients. Unlike synthetic corneal ring implants, CAIRS uses carefully prepared donor tissue. Customised segments are placed within the cornea to reshape and stabilise its structure, improving the regularity of the corneal surface.

Who May Benefit from CAIRS Treatment in London?

patients with mild to moderate keratoconus
people who cannot comfortably tolerate contact lenses
those wanting a biological alternative to synthetic ring implants

The right treatment always depends on an individual assessment by an experienced eye specialist.

Step 1: A Comprehensive Consultation

Every successful treatment starts with a detailed consultation, including a full eye examination to evaluate eye health and confirm whether CAIRS is right for you. The assessment typically focuses on your vision, corneal health, corneal shape and thickness, and how far the keratoconus has progressed. Advanced imaging helps the surgeon build a plan around your specific eyes.

Step 2: Personalised Treatment Planning

No two eyes are alike. Because CAIRS uses donor tissue, the corneal segments can be customised to your own corneal structure rather than a one-size-fits-all solution.

Step 3: Preparing for the Procedure

The procedure is performed under local anaesthesia, typically numbing eye drops, so you stay awake while your eye is comfortably numbed before treatment begins.

Step 4: Creating the Corneal Channel

The surgeon creates a precise channel within the cornea, using either a femtosecond laser or a mechanical technique depending on the clinical approach. The channel sits within the stroma, where the donor segments will later be positioned. Precision here matters enormously, since it allows accurate placement while preserving the surrounding structure.

Step 5: Inserting the Donor Corneal Segments

The customised donor segments are carefully inserted into the channel. These biological segments alter the biomechanical properties of the cornea, helping flatten the cone-shaped area caused by keratoconus. As the shape becomes more regular, many patients notice improved visual quality and less distortion.

Step 6: Corneal Reshaping

improve the regularity of the corneal surface
reduce the cone-shaped distortion from keratoconus
enhance visual clarity
reduce visual distortion, including irregular astigmatism

Because CAIRS uses donor corneal tissue, it is designed to integrate naturally with your own cornea.

What Makes CAIRS Different?

improved biocompatibility
better natural integration
a customised treatment approach
a minimally invasive procedure
preservation of corneal tissue

Are There Any Considerations?

infection
movement or displacement of the donor segments
continued progression of keratoconus
the possible need for glasses or contact lenses after surgery

Every patient receives an individual assessment so the benefits and considerations are discussed properly before proceeding.

Why a Personal Assessment Is So Important

Not every patient with keratoconus needs the same treatment. Severity, corneal shape, vision requirements and overall eye health all influence whether CAIRS is appropriate, which is why a thorough consultation always comes first.

Taking the Next Step Towards CAIRS Treatment in London

Understanding what happens during a CAIRS procedure can make the journey feel far more reassuring. From the initial consultation and detailed corneal assessment through to precise placement of customised donor tissue, every stage is planned around you specifically.

At Optimal Vision, we combine advanced diagnostic technology with consultant-led care to assess whether CAIRS treatment in London is the right option for you, developing an individual plan and providing ongoing support throughout.

Ready to Take the Next Step?

A comprehensive consultation is the best way to find out whether this is right for you. Optimal Vision's consultant-led team, headed by Dr Amir Mani, has carried out more than 35,000 ophthalmic procedures between them, and every recommendation starts with a detailed assessment of your own eyes rather than a standard script.

If you are based in Birmingham, you are welcome to book a consultation at either of our two London clinics, 7 Gower Street WC1E 6HA or Harley Street, Marylebone, both CQC-registered. Many of our patients travel in from outside London for exactly this reason. Call 020 7183 3725 or email info@optimalvision.co.uk, or ask about our fixed, transparent pricing and 0% finance options.

Frequently Asked Questions

What is CAIRS treatment in London?

A minimally invasive procedure using customised donor corneal tissue to reshape the cornea in keratoconus patients, improving corneal regularity and visual quality.

Is CAIRS performed under general anaesthetic?

No, it is typically carried out under local anaesthesia using numbing eye drops.

What happens during the procedure?

The surgeon creates a precise channel within the cornea and inserts customised donor tissue segments that help reshape and improve its structure.

Who may be suitable for CAIRS?

Patients with mild to moderate keratoconus, particularly those who cannot tolerate contact lenses or want a biological alternative to synthetic implants.

Will I still need glasses or contact lenses afterwards?

Some patients still need them after treatment, though vision may improve significantly. Suitability and expected outcomes are discussed at consultation.