NYU Abu Dhabi study identifies brain structures that underlie sight recovery in blind teenagers

Fast facts:

• Congenital cataracts are the leading cause of treatable blindness in children worldwide. In nations where the surgery is widely available, surgery occurs during infancy and there is a good prognosis for the recovery of visual function.
• It is widely accepted that the window for surgical intervention for congenital cataracts closes by the time a child reaches the ages of six to eight years old, as that is a critical period for visual brain development. Restoration of the visual input later in life is generally thought to have limited benefit because the brain will lack sufficient plasticity to adapt to and utilize input from the eyes.

Abu Dhabi, UAE, May 1, 2023: A team of NYU Abu Dhabi researchers, led by Bas Rokers, director of the NYUAD Neuroimaging Center, studied the changes in the brain that can lead to visual skills improvements. The investigators teamed up with Project Prakash, a combined humanitarian and scientific effort to restore sight in curably blind children from rural parts of India. They discovered that improvements in visual functions are linked to changes in white matter pathways, which  connect neurons in different brain regions.

They studied many pathways, but only those involved in high-order visual functions, such as face recognition, were directly linked to the visual improvement. Moreover, researchers saw that the patient’s amount of change in late visual pathways, specifically the posterior callosum forceps, predicted the amount of behavioral improvement. This is a new result that identifies the location of brain changes responsible for behavioral improvement.

In the paper titled White Matter Plasticity Following Cataract Surgery in Congenitally Blind Patients published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), the researchers also confirm that cataract surgery has a greater impact on visual function and brain plasticity if received at younger age, but recovery is still possible even if the eye surgery is received later in adolescence.

The results suggest that sufficient plasticity remains in adolescence beyond the critical period for visual development, allowing patients to partially overcome abnormal visual development and help localize the sites of neural change underlying recovery in blind teenagers. There is therefore a window of time wider than previously thought, during which sight-recovery surgeries can be useful to improve visual perception by altering structural brain plasticity. The team’s research shed light on the definition of the sites of neural change related to sight-recovery, which can guide the development of treatments that attempt to induce neural plasticity through behavioral and surgical interventions.

“The new insights uncovered by our team challenge accepted limitations of sight-recovery surgeries, creating an opportunity for the expanded use of these surgeries that will make many more cases of blindness treatable, worldwide,” said Rokers. “Our work also offers evidence to support the call for the scientific community to reassess the critical period for visual development in adolescents.”

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About NYU Abu Dhabi

www.nyuad.nyu.edu

NYU Abu Dhabi is the first comprehensive liberal arts and research campus in the Middle East to be operated abroad by a major American research university. NYU Abu Dhabi has integrated a highly selective program with majors in the sciences, engineering, social sciences, arts, and humanities with a world center for advanced research. Its campus enables students to succeed in an increasingly interdependent world, and to advance cooperation and progress on humanity’s shared challenges. NYU Abu Dhabi’s high-achieving students have come from some 125 countries and speak over 100 languages. Together, NYU's campuses in New York, Abu Dhabi, and Shanghai form the backbone of a unique global university, giving faculty and students opportunities to experience varied learning environments and immersion in other cultures at one or more of the numerous study-abroad sites NYU maintains on six continents. 

 

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