Woman being tested for glaucoma by an ophthalmologist

Research Studies on Mice Reverse Vision Loss Caused by Glaucoma

Wouldn’t it be great if we could reverse aging? While we don’t want to go completely Benjamin Button, turning those white hairs into brown/black/blond/red hairs again and experiencing the knee joints of a spritely teenager again would be wonderful.

Researchers from Harvard Medical School may have uncovered a new gene therapy to turn back the clock on cells damaged by glaucoma, a blinding eye disease. This treatment is hoped to be applied not only to glaucoma, but also to other diseases caused by aging throughout the body.


What is Glaucoma?

Glaucoma is a disease of the optic nerve of the eye. It is typically known as progressive and irreversible, causing permanent vision loss. Doctors don’t fully understand what causes glaucoma though we do know of various risk factors associated with it, such as elevated pressure inside the eye, and other eye or health problems such as sleep apnea and short-sightedness.

During glaucoma, the cells of the eye’s optic nerve become damaged. Because these neurons carry signals from the eye to the brain necessary for vision, if these cells die, we experience progressive vision loss. The loss of sight in glaucoma typically begins in the periphery of our field of view and if left untreated, continues to advance closer and closer to our central vision. As people are usually less aware of changes in their peripheral vision, glaucoma is known as the sneak thief of sight, and vision loss can progress to quite an advanced stage before someone realizes something is not quite right.

Current treatments for glaucoma focus on slowing the deterioration of vision as much as possible by lowering the pressure inside the eye, but patients are advised that nothing can be done to restore vision that has already been lost (spoiler alert – the aforementioned news out of Harvard Medical School may soon turn this upside down). Glaucoma management has come a long way – we now have eye drop medications, laser therapies, and surgical procedures that can effectively add years onto a person’s remaining vision – but until now, vision that was already lost was forever lost.


The Big News for Glaucoma

In a nutshell, researchers from the Harvard Medical School have successfully reversed the vision loss induced by glaucoma in the eyes of mice by reprogramming youthfulness back into the nerve cells of the eye.

This was achieved by using a modified virus to deliver three specific genes into the mouse retinas. These genes are known to turn back time on cells, returning them to a state of better health and spritely youthfulness, by mending a cellular process known as DNA methylation. As we age, DNA methylation in our cells is thought to go a little wonky, which results in altered gene expression and subsequently impaired function of the affected cells. By inserting those three magical genes into aging cells, old and creaky DNA methylation patterns may be reverted back to their fit and healthy younger selves.

In the course of their experiments, researchers in this study found that mice with damaged optic nerves, when treated with the gene therapy, demonstrated double the number of surviving retinal cells as well as a five-fold higher nerve regeneration compared to mice without the treatment. In addition to this, mice with optic nerve injury specifically mimicking human glaucoma were found to score notably better on tests of visual acuity as well as demonstrate improved optic nerve electrical activity – this is the first time that vision has been restored after optic nerve damage has already occurred. But wait, it gets better – elderly mice with natural age-related vision deterioration also experienced an improvement in sight when administered the gene therapy, while demonstrating the electrical nerve activity of their younger days.

The results of this research represent an exciting era for what has traditionally set the inescapable limits of human life – age. Though immortality is likely still a very long way away, the use of these proof-of-concept experiments may very well pave the way for effective treatments of many age-related ailments, not just glaucoma. If the therapy is found to be successful in further animal models, clinical trials on patients with glaucoma may start as early as two years from now.