Cornea Allogenic Ring Segments (CAIRS)

Keratoconus is a progressive eye condition characterised by thinning and protrusion of the cornea, leading to distorted vision. This results in significant visual impairment that can be challenging to correct with methods such as glasses or contact lenses. As keratoconus affects up to 1 in 84 adults in their 20s in Australia, the need for innovative treatment options becomes increasingly critical. One promising new solution is the use of CAIRS.

What are CAIRS?

CAIRS are implanted donor cornea ring segments designed to support and reshape the cornea. The donor CAIRS segment is inserted into the patient’s cornea after a channel has been created using femtosecond laser.

Who is suitable for CAIRS?

Keratoconus patients who are hard contact lens intolerant with poor vision are excellent candidates for CAIRS. The aim of the procedure is to improve glasses corrected visual acuity. these patients would require either an intracorneal ring segment (ICRS) or a corneal graft to restore vision.

Advantages of CAIRS over traditional ICRS:

1.     Reversible

2.     More effective than traditional ICRS for restoration of vision

3.     Improved biocompatibility

4.     CAIRS has lower rate of extrusion compared to ICRS

5.     Suitable for more patients

6.     Customisable and tailored to individual patient

7.     Covered partially by health insurance

Advantages of CAIRS over traditional corneal graft:

1.     No sutures required for CAIRS vs 16 sutures for corneal graft

2.     Shorter procedure time (1-2 hours vs 30 min)

3.     No risk of globe rupture

4.     Minimal rejection risks

5.     Faster return to work (3 days vs 1-2 weeks off work)

6.     Topical steroids required for 4 weeks for CAIRS vs lifelong for corneal graft

Procedure and Postoperative Care

There are two steps of the procedure. During first part of the procedure, a tunnel is created in the patients’ cornea using femtosecond laser. This is done under a local anaesthetic. During the second part of procedure, the donor cornea segments are carefully inserted into the cornea through the tunnel. The segments are fashioned and positioned to achieve optimal corneal shape. The patient experiences a relatively quick recovery, with most resuming normal activities within a few days.

Conclusion

CAIRS represent a significant advancement in the management of keratoconus, offering a promising solution to restore vision in patients experiencing progressive corneal thinning and distortion.

Dr Rachel Li has completed two corneal surgery fellowships at Royal Perth Hospital and Manchester Royal Eye Hospital and is an highly experienced in managing patients with keratoconus.