Amblyopia, commonly referred to as ‘lazy eye,’ is a vision disorder characterized by poor vision in one eye due to the brain’s preference for the other eye during early development. This condition often results in neural connections in the visual system adapting to focus on the stronger eye, rendering the amblyopic eye less effective even after correcting the original vision impairment. Traditional treatments have proven ineffective beyond early childhood, as the critical neural pathways become established during this formative period.
Recent research conducted by a team led by MIT neuroscientist Mark Bear offers a promising breakthrough. Their study indicates that temporarily anesthetizing the retina of the amblyopic eye for just two days can restore vital neural connections, even in adult subjects. This finding builds upon previous work by Bear’s team, which demonstrated that similar outcomes could be achieved through the anesthesia of both eyes or the non-amblyopic eye, mirroring the traditional method of patching the stronger eye to encourage use of the weaker one.
The study further explored the underlying mechanisms of this phenomenon, revealing that blocking signals from the retina to the brain’s visual processing neurons leads to a burst of electrical activity. This burst mimics the neural patterns observed during early development, suggesting it is essential for the treatment’s success. The researchers found that after anesthetizing the affected eye, the neural activity in the visual cortex showed a more balanced input from both eyes. This indicates a significant improvement in communication between the amblyopic eye and the brain, making it functionally comparable to the other eye. The next phase of research will involve testing this technique across different animal models and, eventually, in human subjects. Bear expressed optimism, noting that if successful, this method could offer a significant advancement in amblyopia treatment without needing to disrupt vision in the healthier eye.
Source: A retinal reboot for amblyopia via MIT Technology Review