BACKGROUND: Considering the extensive neural network of the oculomotor subsystems, traumatic brain injury (TBI) could affect oculomotor control and related reading dysfunction. OBJECTIVE: To evaluate comprehensively the effect of oculomotor-based vision rehabilitation (OBVR) in individuals with mTBI. METHODS: Twelve subjects with mTBI participated in a cross-over, interventional study involving oculomotor training (OMT) and sham training (ST). Each training was performed for 6 weeks, 2 sessions a week. During each training session, all three oculomotor subsystems (vergence/accommodation/version) were trained in a randomized order across sessions. All laboratory and clinical parameters were determined before and after OMT and ST. In addition, nearvision-related symptoms using the Convergence Insufficiency Symptom Survey (CISS) scale and subjective visual attention using the Visual Search and Attention Test (VSAT) were assessed. RESULTS: Following the OMT, over 80% of the abnormal parameters significantly improved. Reading rate, along with the amplitudes of vergence and accommodation, improved markedly. Saccadic eye movements demonstrated enhanced rhythmicity and accuracy. The improved reading-related oculomotor behavior was reflected in reduced symptoms and increased visual attention. None of the parameters changed with ST. CONCLUSIONS: OBVR had a strong positive effect on oculomotor control, reading rate, and overall reading ability. This oculomotor learning effect suggests considerable residual neuroplasticity following mTBI.

Abstract-Accommodative dysfunction in individuals with mild traumatic brain injury (mTBI) can have a negative impact on quality of life, functional abilities, and rehabilitative progress. In this study, we used a range of dynamic and static objective laboratory and clinical measurements of accommodation to assess 12 adult patients (ages 18-40 years) with mTBI. The results were compared with either 10 control subjects with no visual impairment or normative literature values where available. Regarding the dynamic parameters, responses in those with mTBI were slowed and exhibited fatigue effects. With respect to static parameters, reduced accommodative amplitude and abnormal accommodative interactions were found in those with mTBI. These results provide further evidence for the substantial impact of mTBI on accommodative function. These findings suggest that a range of accommodative tests should be included in the comprehensive vision examination of individuals with mTBI.

Primary objective The purpose of this study was to develop an objective way to assess human visual attention using the alpha band component of the visual-evoked potential (VEP). Design and methods Six different attentional conditions were tested: eyes-open, eyes-closed, eyes-closed with backwards number counting, and three rapid serial visual presentation (RSVP) tasks. 18 visually-normal, young-adult subjects (ages 21 to 28 years) were tested binocularly at 1 meter for each condition on two separate days. The Diopsys™ NOVA-TR system was used to obtain the visual-evoked potential (VEP) and extracted alpha-wave and its related power spectrum. Additionally, the Visual Search and Attention Test (VSAT) was administered as a subjective measure of visual attention. Results Subjects exhibited significant decreases in power in the alpha band when comparing the eyes-closed to the eyes-open conditions, with power in the eyes-closed condition being, on average, twice as large. The response from the other four conditions did not reflect the differential attentional demands. The ratio of the power in the eyes-closed condition to the eyes open condition in the lower alpha frequencies (8–10 Hz) was found to be significantly correlated to the group’s performance on the VSAT, especially the 10 Hz component. Conclusions An individual’s ability to attenuate their alpha-component during visual processing may be a predictor of their visual attentional state. These findings solidify the role of the VEP alpha subcomponent as an objective electrophysiological correlate of visual attention, which may be useful in the diagnosis and treatment of human visual-attention disorders in the future.

Vergence eye movements are used to track objects that move in depth in one's binocular visual field to attain and maintain a fused and single percept. The mechanism and control of vergence eye movements involves complex neurological processes that may be compromised in individuals with traumatic brain injury, thus frequently resulting in a wide range of vergence dysfunctions and related near-work symptoms, such as oculomotor-based reading problems. This paper presents a review of the vergence system and its anomalies in mild traumatic brain injury, as well as their diagnostic and therapeutic clinical ramifications. Implications related to brain imaging and human neuroplasticity are also considered.

Abstract-Vergence dysfunction in individuals with mild traumatic brain injury (mTBI) may have a negative effect on quality of life, functional abilities, and rehabilitative progress. In this study, we used a range of dynamic and static objective and subjective measures of vergence to assess 21 adult patients with mTBI and nearwork symptoms. The results were compared with 10 control adult subjects. With respect to dynamic parameters, responses in those with mTBI were slowed, variable, and delayed. With respect to static parameters, reduced near point of convergence and restricted near vergence ranges were found in those with mTBI. The present results provide evidence for the substantial adverse effect of mTBI on vergence function.