Abstract
Purpose:
To evaluate a range of objective measures of basic versional and related reading eye movements before and after conventional oculomotor rehabilitation in individuals with mTBI and oculomotor-based, reading-related vision symptoms. The results were also compared with SHAM training.
Methods:
All laboratory-based basic two-dimensional, versional eye movements (binocular fixation, saccades, simulated reading) were recorded objectively using the Arrington ViewPoint Binocular EyeTracker. The clinically-based, horizontal reading eye movements were recorded objectively using the Visagraph system. All measures were performed in 12 non-strabismic individuals with mTBI (mean age: 29 [± 3] years), who had oculomotor-based reading-related symptoms, before and after oculomotor (fixation, predictable saccades, and simulated reading eye movements) and SHAM training (6 weeks each, 2 sessions/week, 45 minutes/session). In addition, near vision 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 oculomotor training, fixational errors both along the horizontal (p<0.05) and vertical (p = 0.06) directions reduced by ~35%. Similarly, horizontal and vertical saccadic gain increased significantly (p<0.05) by 10-15%. The number of extraneous saccades executed during simulated reading reduced significantly (p<0.05) by 20%. However, saccadic latency and peak velocity were normal both at baseline and following training. With respect to the Visagraph findings, reading rate improved by 25% (from 142 to 177 words/min), and the number of fixations reduced by 20% (164 to 135), both of which were significant (p<0.05). In addition, the increased reading rate correlated with reduction in nearvision symptoms (r = -0.4, p<0.05) and increased subjective attention (r = 0.35, p<0.05). However, SHAM training did not have an effect on any of the parameters tested.
Conclusions:
The versional-based, oculomotor training had a significant positive effect on both basic versional tracking and related reading ability. Such an overall improvement is suggestive of improved rhythmicity, accuracy, and sequencing of saccades following oculomotor-based vision rehabilitation in mTBI as a result of oculomotor learning. In addition, it suggests oculomotor visual system plasticity.
Keywords: 522 eye movements •
672 reading •
650 plasticity