An Australian ophthalmology duo are streamlining keratoconus surgical procedures with their development of the CAIRS Plan tool, which they are making free to colleagues.
CAIRS Plan, developed by Brisbane-based ophthalmologists Dr Brendan Cronin and Dr David Gunn, is a free online tool to help surgeons prepare for corneal allogenic intrastromal ring segment (CAIRS) surgery. A new surgical method, CAIRS is used to treat keratoconus, a condition associated with the thinning of corneal tissue and loss of structural integrity, resulting in a conical shape.
First performed in Australia in 2021 by Gunn, CAIRS is an alternative to traditional methods of implantation of acrylic intracorneal ring segments, which may result in allergenic responses due to the cornea not always responding well to plastic. With a high failure rate, Dr Soosan Jacob, from Dr Agarwal’s Eye Hospital and Research Center in India, developed CAIRS, an alternative method that augments the corneal stroma with additional cornea without removing any of the patient’s corneal tissue.
A key feature of CAIRS is biocompatibility, which distinguishes it from traditional methods. With the use of corneal tissue, it has been reported the body is far less likely to trigger adverse reactions – a normal response to foreign bodies such as acrylic implants. Integration with existing tissue prevents migration or corneal melting and erosion, as is the case with poorly positioned acrylic implants.
Now with access to a new type of surgery, Cronin and Gunn are taking it a step further with CAIRS Plan; a new online tool for ophthalmologists to streamline surgical plans to ensure they execute the surgery as intended. The only one of its kind, Cronin says it allows ophthalmologists to upload corneal topography scans of the patient’s own cornea and create a map of where to accurately place the grafted corneal ring segments.
Cronin and Gunn sought to develop CAIRS Plan after conventional preparation methods, such as the use of spreadsheets to organise data, were complex, inaccessible and impractical. It also sparked a series of instructional videos on Dr Cronin’s YouTube channel.
“We realised we have to make this really easy,” he says.
After many queries from surgeons, the duo decided to develop the website which took six months. The tool is designed for use by surgeons of different levels of experience and is not only targeted at the junior level.
“You don’t drive through the streets of a new city without a GPS, and this is the same thing for the surgery,” Dr Cronin says.
CAIRS hasn’t traditionally been the most accessible surgery due to technological constraints. The required femtosecond laser is expensive and uncommon technology, often requiring surgeons to move lasers from clinic into operating theatres. However, with a recent uptake of CAIRS surgery, which started locally in Brisbane and is now performed in operating theatres nationwide, the website will prove more useful and provide one less impediment to performing the surgery.
The impact of the CAIRS Plan tool has also extended beyond national borders with the technology receiving praise at the European Society of Corneal and Refractive Surgeons (ESCRS) Conference on 8-12 September 2022. The conference, held in Vienna, provided Cronin and Gunn with an opportunity to demonstrate the functionality of their system.
“I was blown away by the response from the conference. People were coming up to us and saying, ‘why hasn’t’ someone thought of this sooner?’, and ‘finally, I will definitely be using this for every case’,” Dr Cronin says.
CAIRS Plan also garnered a response from topographer manufacturers, with companies expressing interest.
With this positive reception of CAIRS Plan at ESCRS, the next step is facilitating easy importation of data directly from the topographer which will extend its applications to different types of topography. Cronin hopes to see scleral and limbal photography incorporated which will allow visualisation of blood vessels and allow for placement of corneal rings with even greater precision.
As opposed to integrating CAIRS Plan directly with existing software, which will incur stringent and expensive medical regulatory requirements, the proposal is to allow surgeons to effortlessly upload their topographical maps directly to CAIRS Plan.
Products were once required to achieve CE marking to guarantee adherence to European General Safety and Performance Requirements (GSPR). However, since the implementation of the European Medical Device Regulation (EU MDR), there are increased risk assessment requirements. Allowing easy import of data to topographers avoids these regulatory hurdles as the website does not perform any measurements or provide any medical advice.
“This keeps medicine moving quickly and makes it adaptable,” Cronin says.
Cronin and Gunn have also designed surgical instruments to match the tight radius of curvature required for CAIRS transplants, which were previously not available. These have recently received TGA approval and are soon expected to be available internationally.
More reading
The role of the optometrist in keratoconus
Collaborative care in keratoconus – Dr Brendan Cronin
Australian-first keratoconus surgery performed in Brisbane