Overview
Corneal Allogenic Intrastromal Ring Segments (CAIRS) represent a significant, modern advancement in the surgical management of keratoconus and other corneal ectatic disorders. Traditionally, synthetic plastic rings (such as Intacs or Kerarings) have been implanted into the cornea to flatten the steep, cone-like bulge characteristic of keratoconus, thereby improving visual acuity and contact lens tolerance.
CAIRS achieves this exact same structural goal, but utilises natural, human donor corneal tissue instead of synthetic plastic. Mr Arthur Okonkwo, a highly skilled and dual fellowship-trained Consultant Ophthalmologist based in Leeds, is at the forefront of offering this innovative procedure. CAIRS involves the precise implantation of custom-cut Keranatural segments of sterile, processed donor corneal tissue into microscopic channels created within the patient’s own cornea. Because the implanted material is natural human collagen, it integrates seamlessly with the patient’s existing corneal structure.
This natural integration offers several distinct clinical advantages over traditional synthetic rings. CAIRS significantly reduces the risk of complications associated with synthetic implants, such as ring extrusion (where the plastic pushes through the surface of the eye), tissue melting, glare, and halos. The procedure aims to regularise the shape of the cornea, reduce astigmatism, and ultimately improve the patient’s functional vision, often allowing them to comfortably wear glasses or specialised contact lenses once again.
Key Benefits
- Natural tissue integration
- Lower complication rates
- Improves corneal shape
- Enhances contact lens tolerance
- Can be combined with CXL
- Expert Consultant care
Conditions Treated
- Mild to Moderate Keratoconus
- Pellucid Marginal Degeneration (PMD)
- Post-LASIK Ectasia
- Contact Lens Intolerance (due to ectasia)
What to Expect
1
Initial Consultation
A detailed discussion of your visual symptoms, previous treatments, and medical history.
2
Diagnostic Assessment
Comprehensive corneal topography and advanced optical coherence tomography (OCT) scans are performed.
3
Treatment Planning
Based on the highly detailed diagnostic scans, Mr Okonkwo calculates the exact size, thickness, and precise placement location required for the donor tissue segments to optimally reshape your specific cornea.
4
The Procedure
The procedure is performed as a day case under local anaesthetic drops.
5
Immediate Aftercare
Following the brief procedure, patients rest comfortably in the clinic before being discharged to return home the same day.
6
Follow-Up Care
Thorough post-operative instructions are provided, including a schedule for prescribed eye drops.
Frequently Asked Questions
How does CAIRS differ from Intacs or Kerarings?
Intacs and Kerarings are traditional synthetic intrastromal rings made of rigid plastic (PMMA). While effective, they carry risks such as glare, halos, and the potential for the rigid plastic to erode through the corneal surface over time. CAIRS achieves the same goal of flattening the cornea but uses natural, sterile Keranatural human donor tissue. Because it is natural collagen, it integrates seamlessly into the eye, significantly reducing these complication risks while providing excellent reshaping results.
Is the CAIRS procedure painful?
The procedure itself is generally not painful. Mr Okonkwo uses strong local anaesthetic eye drops to completely numb the surface of the eye before the surgery begins. Patients may feel a mild sensation of pressure when the femtosecond laser creates the microscopic channels or when the tissue is inserted, but actual discomfort is minimal. Mild grittiness or light sensitivity may be experienced for a few days post-operatively, which is managed with prescribed drops.
Will CAIRS cure my keratoconus?
No, CAIRS is not a cure for keratoconus. Its primary purpose is to reshape and flatten the irregular cone, which improves visual quality and makes it much easier to fit and wear contact lenses or glasses. To actually halt the progression of the disease and stop it from getting worse, CAIRS is very often performed prior toCorneal Collagen Cross-Linking (CXL), which strengthens the corneal tissue.
Is there a risk of my body rejecting the donor tissue used in CAIRS?
The risk of rejecting the donor tissue used in CAIRS is low, however, if rejection occurs it is painless and does not affect the vision; this is because the segments are not placed within the visual axis.. The donor corneal tissue used for the segments is specially processed and sterilised to remove all cellular material (the parts that trigger an immune response). What remains is pure, sterile collagen scaffolding, which the body accepts naturally without the need for long-term anti-rejection medications.
How long will it take to see the final results?
While the physical healing of the eye’s surface occurs within a few days, the actual reshaping of the cornea is a gradual process. You may notice some visual changes early on, but your vision will likely fluctuate for several weeks. It typically takes between 3 to 6 months for the cornea to fully settle into its new shape and for the final visual outcome to be achieved, at which point new glasses or contact lenses can be accurately prescribed.
Quick Info
Duration
The surgical procedure itself is relatively quick, typically taking approximately 20 to 30 minutes per eye.
Recovery
Initial surface healing takes a few days. However, the cornea will continue to reshape and vision will fluctuate for several months before the final visual outcome is achieved.
Specialist Care
All treatment is strictly Consultant-led by a dual fellowship-trained corneal specialist, ensuring expert care at every stage.
Ready to Get Started?
Book a consultation to discuss your symptoms and treatment options.
Ready to Discuss Your Vision?
If you are struggling with keratoconus or contact lens intolerance, advanced natural tissue treatments are available. Book a consultation to explore your tailored options and see if CAIRS is right for you.