How donor corneal tissue is helping preserve vision when other treatments aren’t enough
When most people think about eye health, they think about eye tests, glasses, contact lenses or laser eye surgery. Few have heard of Keratoconus, and even fewer know about one of the latest advances in the treatment of advanced Keratoconus, namely CAIRS.
Yet for people living with Keratoconus and feeling like they’re at the end of the line when it comes to minimally invasive treatment options, this innovative procedure is offering renewed hope by improving the shape and stability of the cornea while potentially delaying, or even avoiding, the need for a corneal transplant.
So, what exactly is CAIRS, and where does it fit into the journey of treating Keratoconus?
First things first: What is Keratoconus?
The cornea is the clear, dome-shaped front surface of the eye that acts like a window, helping to focus light onto the retina so you can see clearly.
In people with Keratoconus, the cornea gradually becomes thinner, weaker and begins to change shape. Instead of maintaining its smooth, rounded curve, it bulges forward into a cone shape. As this happens, vision becomes increasingly blurred, distorted and difficult to correct with ordinary glasses.
Keratoconus often begins during the teenage years or early twenties and may continue to progress for several years if left untreated. Research suggests it affects approximately 1 in every 375 to 2,000 people, although newer diagnostic technology indicates it may be more common than previously believed.
Early diagnosis and treatment are among the most important factors in slowing the progression of Keratoconus and protecting long-term vision.
Where does CAIRS fit in?
One common misconception is that CAIRS is the first treatment for Keratoconus.
It isn’t.
For most patients, the priority is to slow the progression of the disease and stabilise the cornea. It’s important to understand that this is not a vision-correcting procedure. Instead, the aim is to stabilise the cornea so that vision changes more slowly and patients are less likely to need frequent changes to their glasses or contact lens prescription.
This is where Corneal Cross-Linking (CXL) comes in.
Cross-Linking strengthens the weakened collagen fibres within the cornea, helping to slow the progression of Keratoconus. While CXL cannot stop the condition completely, it is recognised worldwide as the gold standard treatment for slowing its progression and is often recommended soon after diagnosis.
However, Corneal Cross-Linking does not reverse or restore the cornea’s shape once it has already bulged or become distorted. Instead, it uses riboflavin (Vitamin B2) eye drops together with ultraviolet light to strengthen the corneal tissue and preserve its current shape. Although this helps prevent further deterioration, patients may still require glasses or specialised contact lenses to achieve their best possible vision.
This is where CAIRS may become an option.
So, what is CAIRS?
CAIRS stands for Corneal Allogenic Intrastromal Ring Segments.
Instead of using rigid synthetic rings, as was done in earlier procedures, CAIRS uses specially prepared donor corneal tissue that is carefully placed within the patient’s cornea. Surgeons implant thin, curved segments of human donor corneal tissue. This additional biological tissue helps flatten the cone-shaped cornea, strengthens it and reduces irregular astigmatism, which may improve the quality of vision.
The donor tissue helps reshape and support the weakened cornea, improving its structure and, in many suitable patients, the quality of vision.
Because the implanted tissue is biological rather than synthetic, CAIRS has generated significant interest among corneal specialists worldwide.
Who is CAIRS for?
It’s important to know that not every person with Keratoconus needs CAIRS.
The procedure is generally considered for patients whose Keratoconus has become more advanced and whose vision remains significantly affected despite earlier treatment, such as Cross-Linking, glasses or specialised contact lenses.
The decision depends on several factors, including:
- the severity of the Keratoconus
- the shape and thickness of the cornea
- the patient’s vision
- whether the condition has stabilised
- individual lifestyle and visual needs
Every patient is different, which is why a detailed assessment by a corneal specialist is essential.
Why is CAIRS attracting attention?
One of the biggest goals in modern Keratoconus management is to preserve the patient’s own cornea for as long as possible.
Historically, patients with advanced Keratoconus often progressed to a corneal transplant (corneal graft) when other treatments were no longer effective.
Today’s approach is different.
Specialists now have more treatment options available before considering transplantation. Procedures such as Cross-Linking and CAIRS aim to preserve the natural cornea wherever possible.
For suitable patients, CAIRS may offer several potential benefits:
- Improved corneal shape
- Better quality of vision
- Greater corneal stability
- Improved tolerance of contact lenses in some cases
- The possibility of delaying or avoiding a corneal transplant
Research into CAIRS continues to show encouraging early and medium-term outcomes, although specialists emphasise that long-term data is still being gathered as the procedure becomes more widely adopted.
Looking beyond the treatment
Perhaps the biggest message is this: Keratoconus doesn’t have to define your future vision.
The earlier the condition is detected, the more treatment options may be available.
Many people dismiss changing prescriptions, increasing astigmatism or blurred vision as simply “needing stronger glasses.” Sometimes that’s true. Sometimes it isn’t.
Regular eye examinations, ideally every six months for patients diagnosed with Keratoconus or those at risk, remain one of the best ways to monitor the condition and detect progression early.
Modern eye care is no longer simply about correcting vision. It’s about slowing the progression of disease, preserving vision and helping patients maintain the best possible quality of life.
For patients with Keratoconus, innovations such as Cross-Linking and CAIRS represent an important shift towards treating the condition earlier, more effectively and more conservatively than ever before.
Could CAIRS be right for you?
If you’ve been diagnosed with Keratoconus or your vision continues to deteriorate despite updated glasses or contact lenses, speak to an experienced corneal specialist.
A comprehensive assessment can determine which treatment plan is most appropriate for your eyes, whether that’s monitoring, Cross-Linking, specialised contact lenses, CAIRS or another option.
Every eye tells a different story. The key is making sure yours is diagnosed early enough to give it the best possible outcome.
If you suspect you may have Keratoconus, book a comprehensive eye assessment. While patients with Keratoconus are not candidates for laser vision correction, the team at JHB Eye Laser Centre can assess your eyes and, where appropriate, refer you to a corneal specialist for further management. Book here for an assessment. https://jhbeye.com/refractive-laser-procedures/#book.
As this is a private hospital, some consultations and procedures may be covered by medical aid, subject to your individual benefits and your specialist’s motivation.
References
- American Academy of Ophthalmology. Keratoconus: Diagnosis and Treatment. https://www.aao.org/eye-health/diseases/what-is-keratoconus
- EyeWorld. CAIRS: A New Option for Keratoconus. https://www.eyeworld.org/2023/cairs-for-keratoconus/
- National Keratoconus Foundation (NKCF). Understanding Keratoconus. https://nkcf.org/
- PubMed: Jacob S, et al. Corneal Allogenic Intrastromal Ring Segments (CAIRS) combined with Cross-Linking for Keratoconus. https://pubmed.ncbi.nlm.nih.gov/
- Pretoria Eye Institute: https://www.eyeinstitute.co.za/