Glaucoma, a leading cause of blindness worldwide, most of the time is diagnosed during a typical eye examination. Over time, accelerated stress within the eye damages the optic nerve, leading to vision loss. Unfortunately, there is no solution to properly predict which patients might lose vision quickly.
Now, while studying mice, rats and fluid removed from the eyes of sufferers with glaucoma, researchers at Washington University School of Medicine in St. Louis have recognized a marker that can predict the extent of damage to cells in the eye that would possibly be used to monitor progression of the disease and the effectiveness of therapy.
The findings are released online recently in the journal JCI Insight.
According to the researcher of this study, Rajendra S. Apte, MD, PhD, the Paul A. Cibis Distinguished Professor of Ophthalmology and Visual Sciences, There hasn’t been a reliable way to predict which patients with glaucoma have a high risk of rapid vision loss. But we’ve identified a biomarker that seems to correlate with disease severity in patients, and what that marker is measuring is stress to the cells rather than cell death. Other glaucoma tests are measuring cell death, which is not reversible, but if we can identify when cells are under stress, then there’s the potential to save those cells to preserve vision.
Glaucoma is the second leading reason for blindness around the world, affecting greater than 60 million individuals. The disease most of the time starts off silently, with peripheral vision loss that occurs so progressively that it may well go neglected. Over time, the central vision may become affected, which can imply that significant damage has already occurred before any treatment begins.
Many patients start receiving cure when their doctors become aware that they have increased pressure in the eye. Those treatments, comparable to eye drops, are aimed at decreasing pressure in the eye, however such healing procedures would possibly not protect ganglion cells in the retina, which are the cells being destroyed in glaucoma, further leading to blindness.
Apte, also a professor of developmental biology and of medicine, stated that all present therapies for glaucoma are aimed toward reducing pressure within the eye to lower ganglion cell damage and are no longer protecting ganglion cells.
Glaucoma treatment specialists attempted to monitor vision loss caused by the death of ganglion cells with the aid of visual field testing. In this procedure, a patient pushes a button after they see a blinking light. As vision is misplaced, patients see fewer lights blinking within the periphery of the visual area, but such procedure is not always reliable, as said by the paper’s first author, Norimitsu Ban, MD, an ophthalmologist and a postdoctoral research associate in Apte’s laboratory.
Some older men and women don’t good on the visual field test for causes that are not related to their eyes' condition, Ban explained. He said that finding a marker of cell damage within the eye could be a much better method to track the development of glaucoma. He commented, We were lucky to be able to identify a gene and are very excited that the same gene seems to be a marker of stress to ganglion cells in the retinas of mice, rats and humans.
By studying mouse models of glaucoma, Ban, Apte and their colleagues identified a molecule within the eye called growth differentiation factor 15 (GDF15), noting that the levels of this molecule grew as the animals aged and developed optic nerve damage.
Once they repeated the experiments in rats, they replicated their outcomes. Further, in sufferers who had eye surgery for glaucoma, cataracts and other issues, the researchers found that those with glaucoma also had higher GDF15 within the fluid of their eyes. Apte remarked, That was exciting because comparing the fluid from patients without glaucoma to those with glaucoma, the GDF15 biomarker was significantly elevated in the glaucoma patients. We also found that higher levels of the molecule were associated with worse functional outcomes, so this biomarker seems to correlate with disease severity.