Canadian and American vision experts have just made an incredible discovery that could change how eye doctors think about treating glaucoma. In their recently published report, researchers show how certain lipid mediators naturally reduce symptoms of this blinding disease.
After injecting mice with glaucoma, researchers observed how lipid mediators reacted in the rodents' eyes. They soon found that certain lipid mediators called lipoxins, which are secreted from cells called astrocytes, helped protect the mice's eyes against retinal ganglion cell loss.
Ophthalmologists have known for some time that lipoxins have an anti-inflammatory effect on the eyes. This study is the first to demonstrate that these lipid mediators also play a major role in protecting essential retinal cells.
Indeed, numerous scientists in the past associated astrocytes with retinal cell loss and optic nerve damage. Researchers involved in this study, however, believe astrocytes actually help slow down the progression of optic nerve decay.
The specific beneficial lipoxins that astrocytes released were called A4 and B4. Study authors note, however, that the astrocytes only released these lipoxins when they were resting.
To better understand lipoxins A4 and B4's healing properties, scientists took a few of the lipid mediators from the rodents' optic nerve heads and retinas and placed them in a culture. They then administered the lipoxins into the eyes of rodents eight weeks after they had been injected with glaucoma.
At the 16-week mark, researchers re-examined the eyes of glaucoma-infected rodents who were injected with lipoxins A4 and B4. They found that B4 in particular helped dramatically slow down the rate of retinal ganglion cell decay.
As of today, eye doctors only thought of using lipoxins in anti-inflammatory drugs. The findings from this study clearly show that lipoxins could be successfully used to create neuroprotective drugs.
The professors involved in this research have already applied for a patent to create drug therapies for glaucoma with lipoxins A4 and B4. They hope to test lipoxin-based drugs in human clinical trials in the near future. If these drugs are successful in reversing glaucoma, doctors believe lipoxins could be used to reverse other neurodegenerative diseases like ALS and Alzheimer's.
Although there are different types of glaucoma, all strains of this eye disease cause serious damage to the optic nerve. A key warning sign of glaucoma is an elevated intraocular pressure (IOP) reading. Visual symptoms of glaucoma only appear after the disease has progressed a great deal, which is why ophthalmologists recommend everyone get a yearly vision screening.
While doctors can't cure glaucoma, they can slow down the disease's progression if they catch it in time. A few common treatment strategies include IOP reducing drops like Latanoprost and laser surgery.
Today, about 80 million people around the world have some form of glaucoma. That makes glaucoma the second leading cause of blindness after cataracts.
Professors John Flanagan, Karsten Gronert, and Jeremy Sivak were the lead authors on this study. Both Drs. Flanagan and Gronert teach optometry at the University of California, Berkeley, while Dr. Sivak teaches ophthalmology at the University of Toronto. Most of the research in this study was conducted at UC Berkeley.
Anyone interested in reading this full study should pick up the November 2017 edition of Journal of Clinical Investigation. This study was published under the title, "Astrocyte-derived lipoxins A4 and B4 promote neuroprotection from acute and chronic injury."