Corneal disease: Hope for an alternative to transplants

An international team, including researchers from three teams and a clinical researcher affiliated with the Hôpital Maisonneuve-Rosemont (HMR) Research Centre, is opening the door to an alternative to corneal transplantation.

Corneal transplantation: The quest for the impossible

Around the world, nearly 13 million people, blinded by corneal disease, are waiting for a transplant. Unfortunately, the shortage of donors means that only 1 in 70 patients can benefit.

Corneal transplants: Little progress for a long time

Moreover, if the success rate of corneal transplants oscillates between 85 and 90% after two years, it drops to 60% after 5 years. This is all the more disturbing, since after a first rejection, new transplants are less and less accepted by the body.

Frequent immune rejection in severely damaged corneas

Also, in patients with inflammation or severe damage to the cornea, the risk of graft failure or rejection is even greater. This explains why treatment options for these patients are so limited.

Finding an alternative to transplantation

Current research is focused on finding an alternative to this tissue shortage and the associated immune rejection problems.

Researchers from this international team have already established that corneal regeneration can be an alternative to transplantation. How? By using collagen-based biomaterials. They have demonstrated that the human cornea can self-heal using this biomaterial. Unfortunately, this first version of the implant cannot stop the inflammation that can lead to implant failure.

What is a biomaterial?

A biomaterial is a substance or material that is intended to be implanted into a living organism to replace an organ or tissue, in this case to repair a cornea.

Role of collagen in our body

Collagen is to the human body what steel rods are to reinforced concrete. If the reinforcing rods are fragile, the structure becomes more fragile. More than twenty types of collagen are found in the tissues of our body: bones, tendons, internal organs, cartilage, and eye structures, etc.

A hopeful study that addresses two critical needs

First, the international team, which includes Drs. May Griffith, Isabelle Brunette and Sylvie Lesage of the Hôpital Maisonneuve-Rosemont Research Centre and Marie-Claude Robert, a researcher affiliated with the Hôpital Maisonneuve-Rosemont Vision Axis, wanted to create a low-cost, easy-to-produce biomaterial for potential global clinical application.

Secondly, this biomaterial must not cause inflammation.

To this end, the team made corneal implants from a low-cost protein that mimics collagen. Then they incorporated a synthetic polymer that suppresses inflammation.

The synthetic polymer or phosphorylcholine

In the clinic, this polymer is used to coat materials, such as stents used to support the walls of blood vessels, in order to prevent the occurrence of thrombosis or blood clots.

A solution with many advantages

This biomaterial:

• Provides for a simpler manufacturing process.
• Offers the possibility of large-scale production for clinical use.
• Reduces corneal inflammation.

Encouraging preliminary results

The implants under study were shown to result in:

• Faster nerve regeneration.
• Recovery of corneal sensation by increasing the transparency of the cornea and thus vision.

The next step is to perform a clinical evaluation of these implants.

About this project

This project is an international effort involving researchers and clinicians from Belgium, Canada, Finland, Spain, Sweden, the United Kingdom, and the United States.

Research grants were provided by the Indo-Swedish DBT-Vinnova Strategic Collaborative Program, the Canadian Institutes of Health Research, the Fonds de recherche en ophtalmologie de l’Université de Montréal, the Caroline Durand Foundation, the Medical Research Council in the United Kingdom, and ISCIII-ERDF/ESF of Spain. One of the researchers, Fiona Simpson, is receiving a doctoral award from the Natural Sciences and Engineering Research Council of Canada.

At the Hôpital Maisonneuve-Rosemont Research Centre, Dr. May Griffith is supported by the Canada Research Chairs Program and a research chair from the Caroline Durand Foundation. Dr. Sylvie Lesage holds a Merit Research Award from the Fonds de recherche du Québec – Santé.

Thanks to our donors

Donors to the Hôpital Maisonneuve-Rosemont (HMR) Foundation also support this project by funding research laboratories, and specialized research platforms such as imaging, animal facilities, and cytometry.

The HMR Foundation also contributed to Dr. May Griffith becoming the Caroline Durand Foundation Research Chair.

The HMR Foundation also funds the infrastructure used by researchers at the Hôpital Maisonneuve-Rosemont Research Centre, most notably the new vision research laboratories, their related facilities, and support staff.

˃ Read Collagen analogs with phosphorylcholine are inflammation-suppressing scaffolds for corneal regeneration from alkali burns in mini-pigs, Nature, May 21, 2021