双眼同治训练对关键期后弱视人群视觉通路的功能重塑机制研究

Amblyopia is the main cause of monocular low-vision in preschool and school children, and adult monocular amblyopia is still a clinical bottleneck to ophthalmologists. With the rise and successful application of new treatment concept——“binocular therapy”, “binocular dysfunction” was regarded as the primary cause of visual deficits in monocular amblyopia. Recent study showed cortical response to amblyopia eye stimulation depended on whether the dominant eye was open, suggesting dysfunctional binocular interactions played an important role in monocular amblyopia. However, whether the subcortical pathway would be involved in the mechanism of binocular dysfunction and how “binocular therapy” drive functional reorganization have not been clearly studied. In our project, we will use advanced fMRI technology to study the functional changes and reorganization of visual pathway under different binocular-viewing conditions in monocular adult amblyopia and to evaluate the effects of various binocular paradigms on the functional responses and metabolic changes, with the goal to investigate the neural mechanism of subcortical pathway during abnormal binocular interactions and provide strategic guidance for binocular therapy in monocular adult amblyopia.

弱视是目前儿童单眼低视力的最主要原因，而关键期后单眼弱视仍面临治疗瓶颈。随着双眼同治理念的成功尝试，双眼交互作用不良被认为是导致关键期后单眼弱视患眼视功能障碍的原发因素之一。近年来虽有报道证实双眼交互作用不良可引起单眼弱视初级视皮层的功能改变，但是此种不良交互作用是否在皮层下视觉通路已存在，双眼同治训练对患者双眼交互作用的影响怎样，是否引起了视觉通路的功能重塑等科学问题尚不明确。本项目以“双眼同治训练可引起关键期后单眼弱视在皮层及皮层下视觉通路的功能重塑”为工作假设，应用功能磁共振成像技术对单眼成人弱视在不同双眼交互作用条件下皮层及皮层下视觉通路的功能信号及重塑进行研究，深入解析该人群中双眼交互不良的神经机制，活体、客观地量化其程度及发生位点，阐明双眼同治训练对弱视皮视觉通路的功能重塑作用，为突破关键期后单眼弱视治疗瓶颈，寻找及优化双眼同治训练提供重要的科学依据及指导意义。

关键期后单眼弱视是目前临床治疗的难点，双眼间抑制逐渐被认为是单眼弱视患眼视功能障碍的原发因素，因此近年来对弱视患者双眼间抑制的研究成为热点。本研究围绕弱视的双眼间抑制及脑功能改变作为研究主线，利用功能磁共振探讨成人弱视皮层下通路损伤，证实了弱视的小细胞通路损伤并首次发现健眼的上丘代偿现象；利用微视野计对难治性弱视之一的旁中心弱视的注视特性，发现旁中心注视性弱视患者的注视区中心凹越远，注视稳定性越差，异常视网膜对应可能是旁中心注视发生的促成因素之一；结合双眼竞争和视动性眼震，研发了一种客观量化单眼弱视患者双眼间抑制程度的新模式，运用此模式可客观量化弱视患者的双眼间抑制程度，该程度与弱视程度成正相关；结合增强现实的方法，研发一种双眼同治训练方法，用于成人弱视患者可以提高其弱视眼的视力及减弱双眼间抑制程度。通过上述的研究，我们利用功能成像与视觉心理物理学方法相结合，探讨弱视患者双眼间抑制程度的机制及脑功能的改变，为今后突破弱视患者的治疗瓶颈提供了科学依据和评估手段。