A recent study has presented a potential treatment for glaucoma, an eye disease that affects 70 million people worldwide and results in vision loss due to high intraocular pressure, or pressure inside the eye that irreversibly damages the optic nerve. The study has shown that lipoxin molecules, secreted by astrocyte cells in the retina, are able to directly protect optic neuronal cells from degeneration.
The study was led by Dr. Jeremy Sivak, the Glaucoma Research Chair at the Krembil Research Institute in Toronto, and involved researchers from the University of Toronto and the University of California, Berkeley. The team of scientists discovered that lipoxins A4 (LXA4) and B4 (LXB4) are the ones with the ability to protect optic neuronal cells.
Until this study, little research had been conducted on LXB4, which turned out to be the more potent lipoxin in the retina. Sivak said that the discovery had the potential to be “transformative” in the current scope of glaucoma treatments, which focus on prevention and lowering intraocular pressure.
“We’ve discovered a new molecule that protects the optic nerve — the nerve connecting the eye to the brain — from damage, [and] that damage is a key feature of the disease glaucoma,” explained Sivak.
“It actually started with… serendipity,” he continued. “[It was] a surprising result [where] we were expecting to see a toxic effect from some of our astrocyte cells [that instead turned out to be] a protective effect, but only when they were under certain conditions — when they… weren’t being stimulated by stress.”
According to Sivak, if these neuroprotective lipoxins are able to be properly utilized in clinical treatment, they would target the disease process directly and could benefit patients with any form of glaucoma. In Sivak’s words, they would get “to the heart of the problem.”
This discovery is also to be explored in the context of neurodegenerative diseases such as Alzheimer’s and Parkinson’s.
“The outer part of the brain and [the] hippocampus also respond to the same signal. That suggests that this mechanism we have discovered is present throughout the brain and raises the possibility that it might be important or at least effective in other neurodegenerative diseases as well,” said Sivak.
Next, the team plans to apply their discovery to understand the optic nerve’s signaling pathway more thoroughly and eventually create targeted treatments for glaucoma patients.