Stem cell injection could reduce the risk of sight loss from glaucoma

New research suggests that an injection of stem cells could help repair the eye’s drainage system in the most common form of glaucoma. The results are published in the journal Proceedings of the National Academy of Sciences.

Glaucoma is one of the top 5 causes of blindness in the UK. It’s the name for a group of conditions that cause permanent sight loss due to the death of retinal ganglion cells. Connections from these cells together form the optic nerve, taking visual information from the light-sensitive layer of the eye (the retina) to the visual brain.

A blocked drain

The most common form of glaucoma (primary open angle glaucoma) is due to a build-up of fluid in the eye. A healthy eye should make and drain fluid away at about the same rate. Fluid helps the eye hold its shape and is drained away through tissue known as ‘the trabecular meshwork’.

But cells in the trabecular meshwork thin out as we age, and the eye’s drainage system can stop working as it should. This leads to high pressure in the eye which in turn can damage the optic nerve.

Less risk of rejection

In the current study, the research team used stem cells to treat a mouse version of glaucoma. The stem cells were first developed from the skin (known as ‘induced pluripotent stem cells’) and then grown into trabecular meshwork cells in a lab dish.

The advantage of using this type of stem cell is that they can be developed from a patient’s own skin, reducing the possibility that they will be rejected by the immune system. They also avoid potential ethical issues.

Treatment triggers self-repair

Results showed that eye injection with the trabecular meshwork cells restored drainage to the mouse eye and prevented further retinal ganglion cell death. Strikingly, the cell injection stimulated the trabecular meshwork into generating its own new cells, replacing the ones that had been lost over time.

Dr Dolores Conroy is Fight for Sight’s Director of Research. She said:

“A key priority for glaucoma research as far as patients are concerned is the development of more effective treatments to prevent vision loss, and so these are very impressive results that could provide a novel approach.

“Restoring the function of the trabecular meshwork using stem cells reduced the intraocular pressure and limited the damage to the retinal ganglion cells whose loss is ultimately the cause for reduced vision in glaucoma. The stem cell treatment was effective for the equivalent of 6 human years and so we don’t yet know whether this could work as a permanent solution, or if multiple treatments should they be required. I look forward to further results and, ideally, its translation to the clinic.”