Does Repeated Stress Accelerate Aging of the Eye

According to recent studies from the University of California, Irvine, aging plays a significant role in the loss of retinal ganglion cells in glaucoma, and new pathways can be targeted for developing new therapies for glaucoma patients. The study was released in Aging Cell and is titled “Stress caused aging in the mouse eye.” Dorota Skowronska-Krawczyk, PhD, an assistant professor in the departments of physiology and biophysics and ophthalmology and a member of the faculty at the Center for Translational Vision Research at the University of California, Irvine School of Medicine, describes the transcriptional and epigenetic changes occurring in the aging retina with the help of her coworkers. The research team demonstrates how stress, such as increased intraocular pressure (IOP) in the eye, promotes epigenetic and transcriptional alterations in retinal tissue that are like those associated with aging. And how repeated stress in early retinal tissue causes signs of accelerated aging, such as an accelerated epigenetic age.

How does Aging Affect the Eye

All cells within an organism are impacted by aging, which is a universal process. It is a significant risk factor for glaucoma, a group of neuropathies that affects the eyes. According to current projections, there will be over 110 million people with glaucoma (aged 40 to 80) by 2040 because of the aging populations around the world.

“Our work emphasizes the importance of early diagnosis and prevention as well as age-specific management of age-related diseases, including glaucoma,” said Skowronska-Krawczyk. “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 the disease is recognized early.”

Measuring Intraocular Pressure in Glaucoma

Intraocular pressure (IOP) in people follows a circadian pattern. It normally oscillates between 12 to 21 mmHg in healthy people, and it tends to be highest for about two-thirds of people during the nocturnal period. A single IOP measurement is frequently insufficient to define the true pathology and risk of disease progression in glaucoma patients because of IOP changes. According to studies, glaucoma progression is strongly predicted by long-term IOP variation. According to this recent study, the tissue's aging is directly caused by the cumulative effect of IOP changes.

“Our work shows that even moderate hydrostatic IOP elevation results in retinal ganglion cell loss and corresponding visual defects when performed on aged animals,” said Skowronska-Krawczyk. “We are continuing to work to understand the mechanism of accumulative changes in aging to find potential targets for therapeutics. We are also testing different approaches to prevent the accelerated aging process resulting from stress.”

These new findings were made feasible by the fact that researchers now have a new technique to quantify the effect of stress and treatment on the aging condition of retinal tissue. Researchers could demonstrate that repetitive, mild IOP elevation can accelerate the epigenetic age of the tissues through collaboration with the Clock Foundation and Steve Horvath, PhD, from Altos Labs, who pioneered the development of epigenetic clocks that can measure age based on methylation changes in the DNA of tissues.

Advertisement

“In addition to measuring vision decline and some structural changes due to stress and potential treatment, we can now measure the epigenetic age of retinal tissue and use it to find the optimal strategy to prevent vision loss in aging,” said Skowronska-Krawczyk.

Source-Medindia