CAIRS, a new treatment for keratoconus

The newest technology for treating keratoconus is corneal allogenic intrastomal ring segments, or CAIRS, which utilises human tissue – a graft of corneal tissue, which you insert into the middle layer of the cornea, the stroma. It reshapes the cornea, and debulks the astigmatism. It’s not going to completely normalise the cornea, but gives it a much more regular curvature.  

After the procedure, the quality of vision is much better. Patients gain lines of vision, even with glasses, because the cornea is a more normal shape. Also, they can wear more normal contact lenses – it doesn’t always have to be a scleral or a specialist lens. Some patients can get by, after CAIRS, with a soft lens.  

This is a new technology in keratoconus, which is really exciting. There are quite a few topography images, showing what happens to the cornea, pre and post-surgery, highlighting the change in shape. CAIRS is a great procedure. There are a few things that I think are game changers in the ophthalmology world. For keratoconus, cross-linking was one, and I think CAIRS will be the second one. 

CAIRS is fairly new. We have been performing it at OCL Vision for the past 11 months or so, and it has been happening elsewhere around the world as well. The technology was created in India, but since then companies have come in. Keranatural is the company that now provides the tissue. 

There are a few things that I think are game changes in the ophthalmology world. Cross-linking was one, for keratoconus, and I think CAIRS will be the second one

The benefit for patients  

For patients who previously had cross-linking, who have an abnormal corneal shape because of their keratoconus, and who are not tolerant to contact lenses and are not seeing well, there is now an option of doing the CAIRS procedure, to give them better quality of vision. Patients who are non-tolerant to sclerals, who otherwise would wear sclerals for best corrected vision, are likely to be suitable to undergo a procedure like this. 

It normalises the cornea slightly, so patients can then get best corrected vision. I had a patient who was 6/60 best corrected pre-CAIRS. I had seen him at Luton and Dunstable University Hospital, and he was completely non-tolerant to sclerals. He came to OCL Vision privately for CAIRS, and he now best corrects up to 6/6. That is incredible. Considering he is non-tolerant of contact lenses, he can now probably wear a soft contact and even glasses, which never would have been possible. 

This technology is also available for patients who haven’t had cross-linking. There is some evidence to say that it could delay the progression of keratoconus, but most patients do have cross-linking six months after. For those who haven’t had anything done, we tend to do CAIRS, and then cross-link six months after. But those who have already had cross-linking can still have the procedure, and they end up with a better corrected visual acuity afterwards, unaided. 

Application for optometry 

I think it’s important that optometrists know this treatment exists. If they have existing patients who can’t be fitted correctly with contact lenses, as patients with keratoconus often can’t, or those who are really struggling with the quality of vision in their glasses, they can have a procedure now that can give them better corrected vision. There is an option there. 

The most important thing for optometrists to know about this service is that it can provide better uncorrected visual acuity, and best corrected visual acuity. Patients could be out of contact lenses. The best vision will always be with a contact lens on top, but there they could function without them.  

It is human tissue, so it’s biocompatible. Results show that it does strengthen the cornea, so for those patients that haven't had cross-linking, there is a benefit of putting it in there just to stabilise the cornea. In my opinion it supersedes the old Intacs option, which had an issue of protrusion.