Effect of vision loss on plasticity of the head and neck proprioception

To investigate whether head and neck proprioception and motor control could be compensatory enhanced by long-term vision loss or impairment.

Individuals who were blind, low vision or sighted were included in the study, which would undergo the head repositioning test (HRT). The constant error (CE), absolute error (AE), variable error (VE) and root mean square error (RMSE) of each subject were statistically analyzed. Data were analyzed using the SAS 9.4. Tukey-Kramer for one-way ANOVA was used for comparison of blind, low vision, and sighted subjects, as well as to compare subjects with balanced vision, strong vision in the left eye and strong vision in the right eye. Independent sample t-test was used to compare subjects with congenital blindness and acquired blindness, as well as left and right hand dominance subjects.

A total of 90 individuals (25 blind subjects, 31 low vision subjects, and 34 sighted subjects) were included in the study. Among the blind subjects, 14 cases had congenital blindness and 11 cases had acquired blindness. Among the blind and low vision subjects, 21 cases had balanced binocular vision, 17 cases had strong vision in the left eye and 18 cases had strong vision in the right eye. Among all subjects, 11 cases were left hand dominance, and 79 cases were right hand dominance. There were significant differences in AE, VE, and RMSE in head rotation between blind, low vision, and sighted subjects (P<0.01), in AE, VE, and RMSE between blind and sighted (P<0.01), and in VE and RMSE between low vision and sighted (P<0.05). No significant difference between blind and low vision (P>0.05). Significant differences in CE and AE of head right rotation and CE of general head rotation between congenital and acquired (P<0.05). No significant differences between left and right hand dominance and in balance or not of binocular vision (P>0.05).

Long-term vision loss or impairment does not lead to compensatory enhancement of head and neck proprioception and motor control. Acquired experience contributes to HRT performance in the blind and has long-lasting effects on plasticity in the development of proprioception and sensorimotor control.