A team led by Professor Guei-Sheung (Rick) Liu is working to change that – developing delivery systems that could transform how a wide range of eye diseases are treated.

In 2025, Professor Liu’s Genetic Engineering Research Unit became the first to use a tiny particle extracted from blood to deliver medicine directly into a preclinical model of the cornea.

This could pave the way for faster, more effective treatment of corneal injuries.

Corneal injuries – whether caused by trauma, chemical exposure or burns – require immediate treatment to preserve vision and reduce scarring.

Anti-inflammatory drugs delivered via eye drop are a critical first step but are far from ideal.

“When you use an eye drop, less than five per cent of the medicine actually stays in the eye – the rest runs out – so it is not as effective as it could be,” Professor Liu says.

To improve this his team looked at platelets – cells in the blood that clump together to heal cuts and prevent bleeding.

When healing wounds, platelets release platelet-derived extracellular vesicles (PEVs) – tiny particles that help with this process.

Professor Liu and his team took these PEVs and loaded them with an anti-inflammatory drug – successfully using them to reduce inflammation.

“They are very small particles that are easily absorbed into the cornea, they naturally occur in the body so won’t trigger the immune system, and because they come from blood they are very easy to source,” Professor Liu says.

“We also found that platelet-derived extracellular vesicles also help reduce inflammation and promote tissue repair a little just on their own, so they are beneficial in many ways.” While corneal injuries are a start, the team’s future research will look at more treatments that could potentially be delivered.

Next-generation

This research is alongside Professor Liu’s team’s ongoing work to develop a host of ways to deliver new treatments to the eye.

This includes a method of replacing regular eye injections for wet age-related macular degeneration with an eye drop.

His team is also continuing to develop a method of editing RNA – the chemical in the body that ferries instructions from DNA to cells.
This has the potential to treat inherited retinal diseases caused by faults in larger genes – like Usher syndrome – that would otherwise be too large for typical gene delivery.

“Finding treatments and cures for inherited retinal diseases, like Usher syndrome, caused by large-sized gene defects, is urgent and at the forefront of our advancement in the field of research,” says Professor Liu.

“With over 300 genes known to be associated with inherited retinal diseases, affecting over two million people worldwide, customised gene editing that achieves safe and effective treatment to prevent vision loss is our priority.”

This story was originally published in Creating the future in sight: Annual Review 2025.