Almost everyone knows someone who wears glasses or contact lenses. Correcting blurry vision is common, especially among aging adults. The National Institutes of Health estimates that nearly 93 percent of people over 70 wear lenses. Unfortunately, not every visual problem associated with aging is so easily corrected.

“Vision is complicated, and we don’t yet have a complete understanding of how it works, let alone how to prevent these complex diseases,” says Juliette McGregor, an assistant professor of ophthalmology at the University of Rochester Medical Center. “Vision is a really fundamental sense that helps us with the activities of daily life, but it also brings us a lot of joy. Sharing a smile or seeing a beautiful sunset are important not just for independence, but also for our well-being. Researchers are working hard to create new technologies and treatments designed to allow people with vision loss to regain some visual performance.”

Researchers have found that in other animals, such as zebrafish, the eye and brain can regenerate after injury, but in humans, this type of regeneration or regrowth does not happen. Cells in the back of the eye, that detect light, process visual signals, and then send that information to the brain, are vulnerable to damage, especially in common age-related conditions like macular degeneration and glaucomas. Once these neuronal cells are damaged and stop working, they cannot regrow or be repaired.

“Ideally, we would prevent these diseases, but we are not yet in a position to do so,” says McGregor. “We can try to slow disease progression, but once neuronal cells are lost, there is nothing we can do beyond helping people to adjust to visual impairment. Research has expanded our understanding of how we see, but there is still much to learn, and whether we can restore high-quality vision after it has been lost is being actively explored.”

What basic research can tell us about vision restoration
What goes awry and causes vision to break down can happen at any stage of life and for a variety of reasons genetics, environmental exposures, injury, or progressive disease and in any part of the visual system.

An issue in the front of the eye, with the lens and cornea, is potentially treatable with glasses or surgery. David Williams, the William G. Allyn Professor of Medical Optics at URochester, developed a method to accurately measure and correct the optical imperfections in the eye, allowing for the development of better corrective lenses both in glasses and contacts. This research also helps improve laser refractive correction surgeries, such as LASIK.

CVS director Susana Marcos is using advanced imaging to create personalized eye models to guide the selection of ocular corrections. Her lab has also created technologies to allow patients to experience the visual outcomes of cataract surgery prior to the procedure, so they can choose the intraocular lens that best meets their needs.

This same technology first developed by Williams’ team at URochester also allows scientists to image single cells inside the living eye. Jesse Schallek, an associate professor of ophthalmology and of neuroscience, adapted this tool, known as adaptive optics ophthalmoscopy, to reveal the dynamics of previously invisible immune cells infiltrating retinal tissue and responding to threats that may jeopardize vision.

Amazingly, it is also possible to record the activity of individual neurons in the living eye with adaptive optics, which presents new opportunities for evaluating the performance of next-generation therapeutics. McGregor’s lab specializes in using these advanced retinal imaging approaches to test and optimize new vision restoration therapies for retinal degenerations. Their aim? Ensuring that the treatments entering clinical trials have the best chance of success.

Source: https://www.rochester.edu/newscenter/eyesight-vision-loss-restoration-can-blindness-be-cured-686022/