Functional activity within the frontal eye fields, posterior parietal cortex, and cerebellar vermis significantly correlates to symmetrical vergence peak velocity: an ROI-based, fMRI study of vergence training.
Functional activity within the frontal eye fields, posterior parietal cortex, and cerebellar vermis significantly correlates to symmetrical vergence peak velocity: an ROI-based, fMRI study of vergence training.
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DOI：
10.3389/fnint.2014.00050
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发表时间：
2014
影响因子：
3.5
通讯作者：
Biswal BB
中科院分区：
文献类型：
--
作者：
Alvarez TL;Jaswal R;Gohel S;Biswal BB
会聚功能不全(CI)是一种常见的双眼视觉障碍，其症状包括双眼/视力模糊、眼睛疲劳和在阅读或其他近距离工作时出现头痛。随机临床试验支持，基于办公室的放松和调节治疗与家庭强化导致患者症状的持续减少。然而，治疗的潜在神经生理学基础尚不清楚。对7名双眼正常对照(BNC)和4名CI患者在18h集中训练前后的功能活动和集中眼球运动进行了量化。持续注视与集中眼球运动的fMRI常规区块设计刺激了额叶眼野(FEF)、顶叶后皮质(PPC)和小脑疣部(CV)的活动。将CI患者的基线测量与训练后的数据集进行配对t检验，发现：(1)FEF、PPC和CV中BOLD信号的百分比变化显著增加(p<；0.02)；(2)4°对称会聚阶跃反应的峰值速度增加(p<；0.01)；(3)CI症状调查(CI)评估的患者症状得到改善(p<；0.05)。凝聚力训练后CI患者的测量结果与BNC中观察到的水平更接近。回归分析显示，BNC和CI受试者在集中训练前后的峰值速度与FEF、PPC和CV内BOLD信号变化的百分比显著相关(r=0.6；p<；0.05)。研究结果对了解脑梗塞患者快速训练后的行为和神经生理变化，从而可能导致视觉症状的持续减轻具有临床意义。
Convergence insufficiency (CI) is a prevalent binocular vision disorder with symptoms that include double/blurred vision, eyestrain, and headaches when engaged in reading or other near work. Randomized clinical trials support that Office-Based Vergence and Accommodative Therapy with home reinforcement leads to a sustained reduction in patient symptoms. However, the underlying neurophysiological basis for treatment is unknown. Functional activity and vergence eye movements were quantified from seven binocularly normal controls (BNC) and four CI patients before and after 18 h of vergence training. An fMRI conventional block design of sustained fixation vs. vergence eye movements stimulated activity in the frontal eye fields (FEF), the posterior parietal cortex (PPC), and the cerebellar vermis (CV). Comparing the CI patients' baseline measurements to the post-vergence training data sets with a paired t-test revealed the following: (1) the percent change in the BOLD signal in the FEF, PPC, and CV significantly increased (p < 0.02), (2) the peak velocity from 4° symmetrical convergence step responses increased (p < 0.01) and (3) patient symptoms assessed using the CI Symptom Survey (CISS) improved (p < 0.05). CI patient measurements after vergence training were more similar to levels observed within BNC. A regression analysis revealed the peak velocity from BNC and CI subjects before and after vergence training was significantly correlated to the percent BOLD signal change within the FEF, PPC, and CV (r = 0.6; p < 0.05). Results have clinical implications for understanding the behavioral and neurophysiological changes after vergence training in patients with CI, which may lead to the sustained reduction in visual symptoms.