Alvarez Tara L, Vicci Vincent R, Alkan Yelda, Kim Eun H, Gohel Suril, Barrett Anna M, Chiaravalloti Nancy, Biswal Bharat B
Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, USA.
Optom Vis Sci. 2010 Dec;87(12):E985-1002. doi: 10.1097/OPX.0b013e3181fef1aa.
This research quantified clinical measurements and functional neural changes associated with vision therapy in subjects with convergence insufficiency (CI).
Convergence and divergence 4° step responses were compared between 13 control adult subjects with normal binocular vision and four CI adult subjects. All CI subjects participated in 18 h of vision therapy. Clinical parameters quantified throughout the therapy included: nearpoint of convergence, recovery point of convergence, positive fusional vergence at near, near dissociated phoria, and eye movements that were quantified using peak velocity. Neural correlates of the CI subjects were quantified with functional magnetic resonance imaging scans comparing random vs. predictable vergence movements using a block design before and after vision therapy. Images were quantified by measuring the spatial extent of activation and the average correlation within five regions of interests (ROI). The ROIs were the dorsolateral prefrontal cortex, a portion of the frontal lobe, part of the parietal lobe, the cerebellum, and the brain stem. All measurements were repeated 4 months to 1 year post-therapy in three of the CI subjects.
Convergence average peak velocities to step stimuli were significantly slower (p = 0.016) in CI subjects compared with controls; however, significant differences in average peak velocities were not observed for divergence step responses (p = 0.30). The investigation of CI subjects participating in vision therapy showed that the nearpoint of convergence, recovery point of convergence, and near dissociated phoria significantly decreased. Furthermore, the positive fusional vergence, average peak velocity from 4° convergence steps, and the amount of functional activity within the frontal areas, cerebellum, and brain stem significantly increased. Several clinical and cortical parameters were significantly correlated.
Convergence peak velocity was significantly slower in CI subjects compared with controls, which may result in asthenopic complaints reported by the CI subjects. Vision therapy was associated with and may have evoked clinical and cortical activity changes.
本研究对集合不足（CI）受试者视觉治疗相关的临床测量指标和功能性神经变化进行量化。
比较了13名双眼视觉正常的对照成年受试者和4名CI成年受试者的集合和散开4°阶跃反应。所有CI受试者均接受了18小时的视觉治疗。在整个治疗过程中量化的临床参数包括：集合近点、集合恢复点、近距正融像性聚散、近距分离性隐斜以及使用峰值速度量化的眼球运动。通过功能磁共振成像扫描，采用组块设计比较视觉治疗前后CI受试者在随机与可预测的聚散运动中的神经相关性。通过测量激活的空间范围和五个感兴趣区域（ROI）内的平均相关性对图像进行量化。ROI包括背外侧前额叶皮质、额叶的一部分、顶叶的一部分、小脑和脑干。三名CI受试者在治疗后4个月至1年重复进行了所有测量。
与对照组相比，CI受试者对阶跃刺激的集合平均峰值速度明显较慢（p = 0.016）；然而，散开阶跃反应的平均峰值速度未观察到显著差异（p = 0.30）。对参与视觉治疗的CI受试者的研究表明，集合近点、集合恢复点和近距分离性隐斜显著降低。此外，正融像性聚散、4°集合阶跃的平均峰值速度以及额叶区域、小脑和脑干内的功能活动量显著增加。几个临床和皮质参数显著相关。
与对照组相比，CI受试者的集合峰值速度明显较慢，这可能导致CI受试者出现视疲劳症状。视觉治疗与临床和皮质活动变化相关，且可能诱发了这些变化。
