The team consisted of 23 congenitally blind patients (aged 7–17 years) from Uttar Pradesh with dense bilateral cataracts who had undergone cataract surgery at different stages of adolescence.
The findings, published in the journal The Proceedings of the National Academy of Sciences (PNAS), showed that improvements in visual functions are linked to changes in white matter pathways, which connect neurons in different areas of the brain.
The team studied several pathways, but only those involved in higher-order visual tasks, such as face recognition, were directly linked to visual improvement.
In addition, the researchers observed that the amount of change in the patient’s late visual pathways, particularly the posterior callosum plexus, predicted the amount of behavioral improvement. This is a new result that identifies the location of brain changes responsible for behavioral improvement.
They also confirmed that cataract surgery has a greater effect on visual function and brain plasticity when received at an early age, but that recovery is still possible if eye surgery is performed later in adolescence.
The results suggest that substantial plasticity persists in adolescence beyond the critical period for visual development, allowing patients to partially overcome abnormal visual development and helping to localize sites of underlying neural change in blind adolescents. meets.
There is therefore a wider window of time than previously thought during which vision-recovery surgery may be useful for improving visual perception by altering structural brain plasticity.
“There is a general belief that children who are born blind (due to cataracts) and remain in that condition for a few months or years, during what is known as the ‘critical period for sensory development’, later develop their visual functions. cannot get back to life, even if they miraculously regain their sight. But this does not seem to be true in many cases,” said Tapan K Gandhi, professor of AI, Department of Electrical Engineering, IIT Delhi.
“Current medical facilities can treat defects in the lens and cornea, and the brain can then start learning about the visual world,” he said.
The research sheds light on the definition of sites of neural change related to vision-recovery, which may guide the development of treatments that attempt to induce neural plasticity through behavioral and surgical interventions.
Bas Rokers, director of the Neuroimaging Center at New York, said, “The new insights uncovered by our team acknowledge the limitations of vision-recovery surgeries, creating an opportunity for the expanded use of these surgeries to treat many cases of blindness.” qualifies.” York University – Abu Dhabi.
“Our work also provides evidence to support the scientific community’s call for a reevaluation of the critical period for visual development in adolescents,” he said.