A collaboration between researchers from the University of California, Irvine School of Biological Sciences, and the School of Medicine serendipitously discovered how some visually impaired adults could start to see because of the brain's capability of partially recovering from inherited blindness.
They were examining treatment for Leber congenital amaurosis (LCA) when they found that synthetic retinoids can also restore vision in adults and not just in children. LCA is a group of inherited retinal diseases that cause severe visual impairment at birth that stems from mutations in over two dozen genes that caused the degeneration and dysfunction of the photoreceptors in the retina.
A Serendipitous Finding: Retinoid Therapy Restored Central Vision Pathway in Adults
According to Medical Xpress, the team wanted to find out if administering chemical compounds in the retina can make a difference for adults with the condition as it did in children.
They worked on rodent models of LCA and were surprised by their findings. Corresponding author Professor Sunil Gandhi in UCI said, "The central visual pathway signaling was significantly restored in adults, especially the circuits that deal with information coming from both eyes."
The signals from the opposite-side eye activated two times more neurons in the brain immediately after the treatment. More so, researchers are mind blown by the long-lasting effects as the signals coming from the same-side eye pathway activated five-fold neurons in the brain after the treatment.
The team noted that the restoration of visual function at the level of the brain is greater than expected from the improvements previously observed at the level of the retina. The findings that the treatment works well in the central visual pathway support a new concept that there is latent potential for the vision that is just waiting to be triggered.
Gandhi said that the findings of the study open exciting research possibilities in the field. He pointed out that it teaches a broader concept that breaks expectations about the possibility for the brain to adapt and rewire. It could help in developing retinoid therapies to rescue central visual pathways in adults with the condition.
They discussed their findings in full in their study, titled "Retinoid therapy restores eye-specific cortical responses in adult mice with retinal degeneration," which is published in Current Biology.
Congenital Blindness Explained
An infant born unable to see or with severe visual impairment has the condition called congenital blindness, per an article in The Health Board. The condition could be caused by many factors, such as certain diseases and genetics. Also, blindness could sometimes happen in children with autism spectrum disorder and mental disability.
Furthermore, a physical defect in the eye or abnormality in the brain could cause blindness in a child at birth. Some are also born blind after getting infected while inside their mother's womb. For example, the viral disease German measles can affect developing babies and cause congenital blindness. But it could also be an inherited condition or due to an injury during childbirth.
For inherited blindness, the rare degenerative disease LCA is also a cause of congenital blindness. In this condition, the retinas in the eye do not function properly because of prematurity or because it has not had the time to develop properly.
The idea of being born blind or with severely impaired vision can be frightening to sighted individuals. One of the resources blind individuals could use is to have a guide dog that is trained to help them move about and even cross the street.
Check out more news and information on Medicine and Health in Science Times.
