Year-end Sale % OFF 
Abstract
Monocular deprivation early in development causes amblyopia, a severe visual impairment. Prognosis is poor if therapy is initiated after an early critical period. However, clinical observations have shown that recovery from amblyopia can occur later in life when the non-deprived (fellow) eye is removed. The traditional interpretation of this finding is that vision is improved simply by the elimination of interocular suppression in primary visual cortex, revealing responses to previously subthreshold input. However, an alternative explanation is that silencing activity in the fellow eye establishes conditions in visual cortex that enable the weak connections from the amblyopic eye to gain strength, in which case the recovery would persist even if vision is restored in the fellow eye. Consistent with this idea, we show here in cats and mice that temporary inactivation of the fellow eye is sufficient to promote a full and enduring recovery from amblyopia at ages when conventional treatments fail. Thus, connections serving the amblyopic eye are capable of substantial plasticity beyond the critical period, and this potential is unleashed by reversibly silencing the fellow eye.
Highlights
Amblyopia is a prevalent form of visual disability that emerges during infancy when inputs to the visual cortex from the two eyes are poorly balanced (Simons, 2005)
We first sought to characterize the impact of temporary retinal inactivation on the cortical responses to visual stimulation in neurotypical mice, initiated at postnatal day (P) 47 which is after the critical period has ended (Gordon & Stryker, 1996)
Recording electrodes were implanted into V1 layer 4 to measure baseline visual evoked potentials (VEPs) in awake, headfixed animals (Figs. 1A-B, S1)
Summary
Amblyopia is a prevalent form of visual disability that emerges during infancy when inputs to the visual cortex from the two eyes are poorly balanced (Simons, 2005). The most common causes of amblyopia are strabismus and asymmetric refraction, but the most severe form—deprivation amblyopia—arises from opacities or obstructions of vision (e.g., by cataract). The current standard of care is to restore clarity (e.g. by cataract extraction) and focus, and promote recovery of the weak amblyopic eye by temporarily patching the fellow eye (Wallace et al, 2018). The effectiveness of occlusion therapy is limited by poor compliance, variable recovery outcomes, and a significant risk of recurrence. Occlusion therapy is largely ineffective if it is initiated after age 10 (DeSantis, 2014) or, in the case of deprivation amblyopia, after the first year of life (Birch & Stager, 1996). The need for improved treatments for amblyopia is widely acknowledged (Falcone, Hunter, & Gaier, 2021; Elizabeth M Quinlan & Lukasiewicz, 2018)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
