The older we get, the more our vision wanes. That’s because our cells age along with us and at the forefront of the aging process are the cells of the eyes. A new study has now brought to light the fact that stress can speed up this process causing eye cells to die sooner than later, leaving you at risk of eye diseases like glaucoma.
Age-related eye disease remains one of the many challenges of aging. A recent study revealed that by age 65, one in three Americans suffer age-related eye diseases, of which glaucoma is the most commonly encountered.
With glaucoma, the optic nerve experiences progressive neurodegeneration, which, if left untreated, can result in permanent blindness. With the world’s aging population growing rapidly, experts estimate the population of people between 40 and 80 years affected by glaucoma to be roughly 110 million by 2040.
Aging contributes to the vulnerability of the optic nerve, making it less able to withstand even a slight increase in intraocular pressure. According to the study authors, pathophysiological stress related to elevated intraocular pressure forces young retinal cells to undergo genetic changes similar to those encountered by older cells. They believe that these changes could explain why many glaucoma patients continue to suffer deterioration in vision even after intraocular pressure has been lowered.
“The epigenetic changes we observed suggest that changes on the chromatin level are acquired in an accumulative way, following several instances of stress. This provides us with a window of opportunity for the prevention of vision loss, if and when the disease is recognized early,” says study author Dorota Skowronska-Krawczyk.
Methodology
To arrive at their findings, the researchers used a sampling system called a mouse model, where laboratory mice are used as specimens to study certain aspects of human physiology. For this study, eye pressure (a form of stress), was elevated in a group of mice of two different ages: 3 months and 18 months. The impact of this elevated pressure on the aging of the eyes’ cells and also on visual functions were then measured using different functional assays.
Results
The results revealed that subjecting young retinal cells to stressors like elevated intraocular pressure prompted functional and molecular changes characteristic of sterile inflammation and cell death—both known to be associated with aging.
The results also revealed that these aged-up retinal cells were more sensitive and responded much more severely to mild intraocular pressure elevation compared to their younger counterparts.
These changes seen in these cells are a reflection of modifications taking place on a genetic level. The study authors explain that exposure to stress makes genetic materials like chromatins, more accessible and susceptible to changes that alter gene expression.
With these new findings, therapeutic agents capable of preventing accelerated aging from stress as well as a reliable management approach for glaucoma in the elderly can be discovered.
