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CAIRS

CAIRS stands for Corneal Allogenic Intrastromal Ring Segments. CAIRS is a treatment for keratoconus that aims to improve the shape of the cornea by placing small ring segments made from donor corneal tissue in the patient’s own cornea.
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What is CAIRS?

During CAIRS, small semicircular segments made from donor corneal tissue are placed in the cornea. These segments help make its shape more regular.

Unlike conventional synthetic ring segments, CAIRS uses biological donor tissue. As a result, the ring segments integrate more effectively into the cornea and there is less risk of the material being rejected.

CAIRS can be combined with corneal cross-linking to slow further weakening of the cornea. The treatments can be performed at the same time, but it is preferable to perform them sequentially.

Aim

CAIRS has several aims

  • Makes the cornea more regular.
  • Improves visual acuity.
  • Avoids or delays a corneal transplant.

What does CAIRS involve?

  • The procedure usually takes approximately 30 to 60 minutes per eye.
  • You should expect to spend 2 to 3 hours at the hospital.
  • The treatment is performed as an outpatient procedure. You may return home the same day.

Before the procedure

  • You are first given anaesthetic eye drops.
  • The eye is then disinfected and covered.
  • A mild sedative is also usually administered.

Treatment

  • The surgeon uses a femtosecond laser to create small tunnels in the cornea.
  • The donor segments are carefully inserted into these tunnels.
  • The position of the segments is precisely tailored to the shape of your cornea.

Aftercare

The eye may be sensitive during the first few days after the treatment.

Possible symptoms after CAIRS include:

  • A gritty or irritating sensation
  • Sensitivity to light
  • Watery eyes
  • Temporarily blurred vision

Most patients can gradually resume their usual activities after a few days.

After the treatment, use eye drops for several weeks.

How do you put eye drops in your eye?

How should you use eye drops? Follow these guidelines to administer eye drops correctly to yourself or someone else.

Important precautions

  • Do not rub the eye.
  • Use the prescribed eye drops correctly.
  • Protect the eye from dust, dirt and sunlight.
  • You must temporarily refrain from swimming or taking part in other sports.
  • Attend all scheduled follow-up examinations.

Outcome: recovery of vision

Vision usually improves gradually over a period of weeks to months.

Most patients will still need glasses or contact lenses after the treatment, but often experience better quality of vision than before.

Possible risks and complications

Complications are rare, but as with any eye operation, there are risks:

  • Infection
  • Inflammation
  • Displacement of a segment
  • Temporary glare or halos
  • Insufficient improvement in vision
  • Scarring

Your ophthalmologist will discuss in detail beforehand whether CAIRS is suitable for you and what results you can expect.

Follow-up examinations

Several follow-up appointments at the laser centre are scheduled after the treatment. During these appointments, we closely monitor the healing of the cornea and changes in your vision.

Last edit: 25 july 2026