Gene therapy has shown promise for offering neuroprotection for people with glaucoma, a leading cause of blindness across the globe.

The study, published in Cell and supported by the National Institutes of Health National Eye Institute, found that gene therapy can protect optic nerve cells and preserve vision in mice with glaucoma.

The Role of Optic Nerve Cells in Glaucoma

Glaucoma develops when the optic nerve degenerates; the optic nerve is a “bundle of axons from retinal ganglion cells that transmits signals from the eye to the brain to produce vision,” according to the press release. 

Currently, there are therapies that focus on lowering high intraocular eye pressure (IOP) to slow down vision loss, but in some cases, the eyes do not always respond. Therefore, gene therapy provides the people who are unresponsive to that strategy.

Findings from the Cell study

The researchers analyzed the CaMKII (calcium/calmodulin-dependent protein kinase II) pathway, which is known for regulating cellular processes throughout the body, including those for the retinal ganglion cells in the eye. 

“Our study is the first to show that activating the CaMKII pathway helps protect retinal ganglion cells from a variety of injuries and in multiple glaucoma models,” according to the study’s lead researcher Bo Chen, Ph.D., associate professor of ophthalmology and neuroscience at the Icahn School of Medicine at Mount Sinai in New York City.

Chen’s team found that the CaMKII pathway signaling malfunctions when retinal ganglion cells are exposed to toxins or trauma from a crush injury to the optic nerve but that gene therapy could be protective to the retinal ganglion cells.  Administration of the gene therapy to mice prior to the toxins or trauma increased CaMKII activity and protected the retinal ganglion cells. 

In particular, they found:

• 77% of retinal ganglion cells survived 12 months after the toxic insult compared with 8% in control mice. 
• When analyzing the retinal ganglion cells six months after the trauma insult, 77%  of the cells had survived versus 7% in controls.

What This Means for the Future

By increasing the survival rates of retinal ganglion cell survival rates, there is a greater likelihood of preserving visual function. After performing three vision-based behavioral tests, the researchers also found that this visual function was sustained among the treated mice.

“If we make retinal ganglion cells more resistant and tolerant to the insults that cause cell death in glaucoma, they might be able to survive longer and maintain their function,” Chen explains.

Any sources from outside of Prevent Blindness do not imply an endorsement from Prevent Blindness. The contents of the material used are the responsibility of the authoring organization, Responsum Health.

The treatment discussed in this article is experimental and has not been approved by the FDA or any regulatory authorities for any use outside of clinical trials. Its safety and efficacy have not been evaluated by The U.S. federal government. If you are considering participating in a clinical trial, learn more about the risks and potential benefits of clinical studies and talk to your healthcare provider before joining.

*NIH. (2021, July 22). Scientists discover gene therapy provides neuroprotection to prevent [Press release]. https://www.nih.gov/news-events/news-releases/scientists-discover-gene-therapy-provides-neuroprotection-prevent-glaucoma-vision-loss