What part does the white of the eye play in glaucoma?

Research details

  • Type of funding: Project Grant
  • Grant Holder: Dr Craig Boote
  • Institute: Cardiff University
  • Region: Wales
  • Start date: January 2012
  • End Date: February 2015
  • Priority:
  • Eye Category:


Glaucoma is one of the leading causes of sight loss in the UK. It’s often linked to high pressure in the eye, which can squeeze and damage the cells that form the optic nerve (retinal ganglion cells). This can lead to permanent sight loss.

The main site of damage in glaucoma is at the optic nerve head, where 1-2 million retinal ganglion cell connections come together. And the potential damage that high eye pressure can cause is transmitted to the optic nerve head via the white of the eye (the sclera).

So in this project, the research team was trying to find out more about how the sclera behaves under high eye pressure conditions. They used high-power x-ray and microscope technology to study the way collagen is arranged within the sclera. (Collagen is one of two types of protein that make up the sclera.)

The team used their detailed observations to build computer models that predict the mechanics of how the sclera responds to high pressure in the eye.

High eye pressure rearranges collagen

Their results show that as eye pressure rises, collagen in the sclera rearranges in a way that could make optic nerve damage more likely. This is really interesting because it could open up a whole new approach to developing treatment for glaucoma.

At the moment the main treatment for glaucoma due to high eye pressure is by trying to lower the pressure. But this doesn’t work for everyone.

This study shows that it might be possible to halt sight loss by changing the mechanics of the sclera instead, for example by ‘collagen cross-linking’. This is a treatment that’s used in keratoconus to make the front surface of the eye (the cornea) stronger.