Study Suggests Vision Restoration May Be Possible for Glaucoma Patients

A new study from Harvard Medical School (HMS) and Boston Children’s Hospital has good news for the approximately 4 million Americans currently suffering from glaucoma.

Using a combination of gene therapy and a channel-blocking drug that helps pass along impulses from the eye to the brain, researchers were able to improve sight in mice with optic nerve injury. And though the study was conducted in mice, researchers believe the technique may eventually work in humans as well—big news, since glaucoma is the leading cause of blindness in the U.S.

There is currently no cure for glaucoma, which is the result of damage to the optic nerve and can lead to vision loss or blindness. If caught early, there are various medicines and conventional surgeries that can reduce the risk of vision loss. As glaucoma rarely presents symptoms early on, however, action isn’t always taken until after damage has begun.

One previous study at Boston Children’s Hospital was able to achieve partial vision restoration in mice, but it relied on genetic techniques that can only be done in a lab, and used genes that could possibly increase cancer risk.

The method used in the new study, however, could more plausibly be used on a large scale. The researchers used a gene therapy virus called AAV to regenerate the nerve fibers in the eye and form connections with brain cells, enabling them to again carry impulses necessary for sight. Eventually, the researchers hope to achieve a similar result using drugs alone.

“The gene therapy virus we used is approved for clinical study in eye disease, but a medication would be even better,” said Zhigang He, HMS professor of neurology at Boston Children’s, in a statement.

“The drugs might need to be paired with visual training to facilitate recovery,” added Michela Fagiolini, HMS assistant professor of neurology at Boston Children’s, “but now we have a paradigm to push forward.”