Measuring eye pressure in glaucoma research using iPerfusion

Researchers at Imperial College London have developed a tool that could change our understanding of one of the eye’s critical systems. The results, which were part-funded by Fight for Sight, could make it easier to develop new drugs for glaucoma that target the main cause of elevated eye pressure.

High pressure in the eye – known as intraocular pressure – is the main risk factor for glaucoma. Sight loss from glaucoma is irreversible and reducing intraocular pressure is the only successful way to prevent further visual impairment.

A clogged drain

Intraocular pressure is determined by a balance between the rate at which the eye makes and drains aqueous humour – the clear watery fluid that fills the front part of the eye. High eye pressure happens when the fluid meets more resistance than normal as it tries to drain away.

In glaucoma, aqueous humour drainage becomes partly blocked and, like a clogged drain, pressure in the eye rises, a bit like an overflowing kitchen sink. But no one has identified the clog yet despite decades of research.

Mice have small eyes

Animal studies in mice are often used in research to study the mechanics that control drainage from the eye. However the small size of the mouse eye has made this technically challenging.

In this study, the research team describes a new tool for research called iPerfusion™. It includes a device for pressure control, a sensor and a computer interface as well as information on how to take the measurements and analyse the data.

Unexpected results

Using iPerfusion™ the team has shown that the relationship between flow and pressure through the drainage pathway of mouse eyes is more complex than we thought. This could have a big impact on how much we can rely on some earlier glaucoma research results. And ultimately it means researchers can use their new understanding to develop better sight saving drugs for people with glaucoma.

The research was led by Dr Darryl Overby of the Department of Bioengineering at Imperial College London and published in PLoS ONE. The study was also supported by the Engineering and Physical Sciences Research Council (EPSRC).

Read the full press release here (PDF) or (plain text) and you can read more about Dr Overby's research project, below.