Advanced Precision for Complex Corneal Transplants – Femtosecond Laser PK
FDA Approved
Advanced Technology
At a Glance
Quick facts about CAIRS (Corneal Allograft Instrastromal Ring Segments) to help you understand the basics:
- Treatments offered
CAIRS (Corneal Allograft Intrastromal Ring Segments)
- Finance
Transparent pricing and full aftercare support; financing options discussed during consultation
- Why Choose
Specialist corneal team, access to advanced diagnostics, and innovative graft-tissue ring technology
- Locations
London, Sussex, Surrey
Key Benefits
- Tissue-based solution
- Preserves the cornea
- Improves vision quality
- Minimally invasive
- Reversible and adjustable
- May delay or avoid transplant
- Consultant-led expertise
What is CAIRS?
CAIRS is a modern surgical option for Keratoconus in which arc- or ring-shaped segments made from donor corneal tissue (rather than plastic) are inserted into tunnels created in the cornea. These biological segments help to regularise the corneal shape, reduce irregular astigmatism and improve vision quality.
At Centre for Sight, this treatment is offered when glasses or contacts no longer control vision effectively, and you seek a less invasive reshaping solution before full-thickness transplant is needed.
Types of Keratoconus Treatments
1
Glasses / Soft Contact Lenses
First line treatment for mild keratoconus.
2
Scleral / Rigid Contact Lenses
For more advanced shape irregularity.
3
CXL (Corneal Collagen Cross-Linking)
Strengthens the cornea to slow progression.
4
Intrastromal Ring Segments
- Synthetic rings (e.g., Intacs, Ferrara) – plastic segments inside cornea.
- CAIRS (Keranatural) – donor tissue rings for improved biocompatibility and customisation.
5
Corneal Transplantation (DALK / PK)
When more severe scarring or thinning requires grafting.
Comparing Ring-Based Keratoconus Treatment Options
Please note that your consultant will recommend the most suitable treatment option tailored to your specific case.
Procedure Type
How it works
Best For
Pros
Cons
Procedure Type
CAIRS - Keranatural (Corneal Allograft Intrastromal Ring Segments)
How it works
Donor corneal tissue segments are placed into tunnels within the cornea to gently reshape and regularise the cone.
Best For
Patients with moderate keratoconus experiencing visual distortion but not yet requiring a transplant.
Pros
Uses natural corneal tissue → more biocompatible
Cons
Recovery and shape stabilisation can take time
Procedure Type
Synthetic Ring Segments (e.g. Intacs, Ferrara)
How it works
Plastic ring segments are inserted into the cornea to flatten the cone and reduce irregular astigmatism.
Best For
Patients who are not suitable for glasses alone and who want to delay transplant.
Pros
Minimally invasive procedure
Cons
May offer less natural shaping compared to CAIRS
Procedure Type
DALK (Deep Anterior Lamellar Keratoplasty)
How it works
The front layers of the cornea are replaced with donor tissue, preserving the inner endothelial layer.
Best For
More advanced keratoconus where corneal thinning and scarring are significant but the endothelium is still healthy.
Pros
Preserves patient’s own endothelium → lower rejection risk
Cons
Surgical complexity requires specialist expertise
Procedure Type
PK (Penetrating Keratoplasty or Full-Thickness Transplant)
How it works
The entire cornea is replaced with a donor graft.
Best For
Severe keratoconus, scarring, extreme thinning, or failed previous procedures.
Pros
Comprehensive option when other treatments are insufficient
Cons
Requires lifelong monitoring and suture management
What are the Benefits and Risks of CAIRS?
Your consultant will provide a personalised risk-and-benefit discussion based on your eye’s specific needs.
Benefits of CAIRS - Keranatural:
Uses donor corneal tissue → superior biocompatibility and customised shape support
Regularises corneal contour, often improving vision quality and comfort with lenses
Minimally invasive compared with full-thickness transplant
Preserves future treatment options
Risks/side effects (not exhaustive):
Mild discomfort or fluctuating vision during healing
Rare need for segment adjustment or removal (~5-10% cases)
Long-term data still maturing for this new technology
Glasses or contact lenses may still be required for best vision
Not Sure If You're Eligible?
Book a comprehensive eye examination to better understand your vision and available treatment options.
Am I Suitable for CAIRS?
Your surgeon will speak with you about the benefits and risks involved before your procedure.
You may be a candidate for CAIRS if you:
Have keratoconus with thinning or bulging of your cornea and vision affected by distortion
Have keratoconus with thinning or bulging of your cornea and vision affected by distortion
Wear glasses or contact lenses and experience reduced comfort, changing prescriptions, or intolerance
Have corneas not too thin, excessive scarring, or irregular cones that still allow intrastromal insert placement
Wish to delay or avoid a full corneal transplant
You may be less suitable if:
You have advanced scarring, very thin tissue, or previous graft failure
You have uncontrolled eye surface disease, active inflammation or infection
Your surgeon will perform detailed diagnostics (topography, tomography, thickness maps) and tailor a plan for you.
Costs and Finance Options
Transparent pricing will be provided in your consultation. Costs vary depending on the number of segments, complexity of the cornea, and whether combined treatments (e.g., CXL) are required. Flexible finance plans are available to spread the investment comfortably (subject to status and eligibility).
Additional Procedures
Corneal Collagen Cross-linking
Bespoke Price
Per Eye
Consultant-led stabilisation treatment
Strengthens weakened corneal tissue
Minimally invasive, outpatient procedure
Outpatient treatment using riboflavin and UV light
24-hour emergency support
Comprehensive care package
1-year structured follow-up
CAIRS - Keranatural
Bespoke Price
Per Eye
Consultant-led corneal surgery
Natural donor tissue segments (no synthetic implants)
Femtosecond laser–assisted placement
Preserves corneal tissue and structure
24-hour emergency support
Comprehensive care package
1-year structured follow-up
Ferrara Rings
Bespoke Price
Per Eye
Consultant-led refractive corneal procedure
Synthetic intrastromal ring segments
Improves corneal shape and visual function
Femtosecond laser–assisted implantation
24-hour emergency support
Comprehensive care package
1-year follow-up care
Flexible Financing Options
Private Medical Insurance
Many of our Consultants work with all the major insurance providers*
Self-Pay
Pay in full for patients who prefer a straightforward approach
0% APR Financing
6-24 month payment plans with approved credit
Military Discount
5% discount for active military and veterans
*Private Medical Insurance is unlikely to cover Laser Eye Surgery Procedures, Implantable Contact Lenses, or Laser Lens Replacement
FAQs
Here are answers to some of the most common questions patients ask about CAIRS (KeraNatural), helping you understand the treatment, recovery, and whether it may be right for you.
Will I still need contact lenses after CAIRS?
Is donor tissue safe?
Can CAIRS be removed or revised?
How does CAIRS prevent keratoconus progression?
Why choose Centre for Sight for CAIRS?
Our corneal team are specialists in keratoconus management, offering advanced diagnostics and access to new tissue-based technologies in a dedicated environment.
Have Questions?
Our patient care team is here to answer any questions you may have.
Patient Success Stories
A first class experience
The whole process, start to finish, is first class. The facility at East Grinstead is superb and the staff were friendly and professional. The consultant, Saj Khan, is fantastic, a great communicator as well as being a leader in his work.
I had replacement lenses, after 3 months they became a little cloudy, distorting my vision. This is a known problem. I booked a consultation, within 2 hours I had been assessed and had laser treatment. No fuss, no problem, job done.
Laser Lens Replacement
Richard Black
Lens Replacement with Mr Shahnazaryan
The staff, experience and ultimately the outcome is why I have given this review a 5star. Mr David Shahnazaryans manner and expertise is outstanding. Whilst in the theatre Dr Lam kept me relaxed and comfortable with her kindness and fantastic professionalism. All the staff at CFS from the admin team, reception, clinic and theatre were excellent. I recommend them to everyone.
Laser Lens Replacement
Laser Lens Replacement
karen ryan
Laser lens replacement with trifocal lenses
I had Laser lens replacement with trifocal lenses for both eyes and the results are just amazing. The thorough testing and information I received pre and post operative was excellent. I highly recommend Mr Sheraz Daya who in my opinion is an “eye god” his lovely wife and highly professional team to anyone seeking this type of surgery.
Laser Lens Replacement
Susan Gifford
Professional Actor
5* Lens Replacement Procedure
I had tri focal lens replacement, both eyes done on the same day by Mr Daya. I wish I’d had it done sooner, it’s totally life changing. I researched the procedure for many months and selected Centre for Sight and I’m so glad I did. The whole process is first class from the very first contact, the initial tests could not be more thorough and the procedure is totally painless. The whole team could not be more helpful, I cannot praise them enough. I have perfect all round vision now so if you’re considering having the procedure done then this is definitely the place to choose you won’t regret it
Laser Lens Replacement
Jayne Chandler
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