A study published in Communications Biology by researchers from the University of Michigan compared the efficacy of monocular and binocular interventions on amblyopia and the corresponding impact of sleep following this therapy.
Give me some background.
Dominant eye patching has long been the standard of care for amblyopia.
However, studies have shown that this treatment does not restore function in binocular V1 (bV1) neuron visual responses, which is critical to addressing the underlying cause of amblyopia.
Further, recent animal studies have shown that under specific conditions, binocular vision therapy can restore the binocularity of responses in cortical neurons.
As such, researchers are exploring a new therapeutic approach called intensive binocular experience—which is aimed at promoting cooperative input from the two eyes to bV1—to treat amblyopia.
Talk about the study.
To replicate the long-term loss of visual information caused by amblyopia in human brains, researchers occluded one of the two eyes in the participating male mice. Then they compared how monocular and binocular visual stimulation and subsequent sleep affected the overall recovery of bV1 responses.
Tell me more.
Investigators optimized the visual stimulation during these binocular and monocular recovery experiences with high-contrast gratings and engaging environmental stimulation to create a condition that could be feasibly translated to visual therapy for human patients with amblyopia.
Findings?
Researchers found that binocular visual stimulation is quantitatively superior in restoring binocular responses in visual cortex neurons; however, this recovery was only observed in freely-sleeping mice.
Of note, mice with post-treatment sleep deprivation did not have functional bV1 recovery.
Conclusion?
The study authors concluded that binocular visual experience and subsequent sleep help to optimally renormalize bV1 responses in a mouse model of amblyopia.
Significance?
Sara Aton, a researcher from the study, noted: “These findings suggest that patching therapy may be inferior to more recently developed methods aimed at making the eyes work together to treat the condition.”
Further, the timing of sleep relative to treatment is potentially a critical but often overlooked consideration for treating amblyopia.