Myopes Show Greater Visually Induced Postural Responses Than Emmetropes

Abstract

PURPOSE. The literature already establishes that vision plays a crucial role in postural control and that this visual dependence shows intra-and interindividual variability. However, does ametropia also have an effect on postural control? This question leads to our study, which aims primarily to determine if myopes and emmetropes behave differently in terms of postural control when subjected to visual stimulation, and secondarily, if this difference persists in the presence of barrel and pincushion distortions. The results could lead, among other things, to improved lens design.METHODS. Twenty-four subjects (12 myopes of À2.00 to À9.00 diopters [D] and 12 emmetropes of À0.50 to þ0.50 D), between 19 and 35 years of age, participated in the study after comprehensive eye examinations were carried out. Of the 12 myopes, the preferred type of correction was divided equally within the group. While standing in front of a projection system and fixating on an immobile point, a checkerboard stimulus was displayed in their peripheral visual field, in either a static or dynamic state. Three conditions of optical distortion (plan, pincushion, and barrel distortions) were presented to the subjects. Their postural response was measured and recorded using a system of infrared cameras and optical sensors positioned on a helmet. RESULTS.The results show that postural instability induced by a dynamic peripheral stimulus is higher for myopes compared with emmetropes (ANOVA Refractive Error, F 1,22 ¼ 5.92, P ¼ 0.0235). When exposed to optical distortions, the two groups also have significant differences in postural behaviors (ANOVA Refractive Error*Optical Distortion, F 2,44 ¼ 5.67, P ¼ 0.0064).CONCLUSIONS. These results suggest that refractive error could be a factor in explaining individual variations of the role of vision in postural control.

Clinical characteristics of visual motion hypersensitivity: a systematic review

“…Several other risk factors have been identified as contributing towards VMH in isolated studies. These include cerebral palsy (Yu et al 2018 , 2020 ), lower back pain (Li et al 2014 ), myopia (Sayah et al 2016 ), otitis media (Casselbrant et al 1998 ), and stroke (Bonan et al 2013 ; Yelnik et al 2006 ). These studies found respective patient group to exhibit increased postural sway during visual motion.…”

Characteristics of the postural stability of the lower limb in different visual states of undergraduate students with moderate myopia

“…In a study on the effect of corrected vision on postural stability, Bae et al (2020) found that the static postural stability of uncorrected visual acuity (without glasses) was significantly lower than that of the corrected state. People with myopia were more unstable than those with emmetropia in terms of visual-evoked postural response ( Sayah et al, 2016 ). When myopia progresses to a certain extent, it causes blurring of visual information and decreases contrast sensitivity and stereoscopic perception ( Ikuno, 2017 ), which leads to a decline in postural stability.…”

“…Myopia was also significantly higher than corrected visual acuity in the middle- and high-frequency spectral energy of the somatic system. Sayah et al (2016) found that people with myopia were more unstable than those with emmetropia in terms of visually induced postural responses. The postural stability includes both static and dynamic aspects, and testing static stability alone cannot fully explain the characteristics of postural stability in people with myopia.…”

Uncorrected low hyperopia in young subjects induces postural instability even in those with clear visual acuity

“…Paulus et al [14] reported an increase in postural instability of about 25% increase due to myopic blur induced by +4.0 D and +6.0 D lenses and a similar finding in subjects with myopic refractive error between—3.0 and—5.0 D without wearing of corrective spectacles. Recently, Diane et al investigated the effects of optical distortion (Plano, pincushion of +10% and barrel of -10% distortion) on postural stability in myopes and emmetropes, and reported that peripheral dynamic visual stimuli was a more important factor influencing the posture of myopes versus that of emmetropes in both plano and barrel of -10% distortion [15]. Many previous studies demonstrated that refractive error significantly interfered with postural stability [13,14,16,17], but those studies had the limitation of inability to calculate the minimum refractive power that degrades postural stability; Moreover, although hyperopia is a common type of refractive error, most of those studies focused only on myopic blur [13,14,16,17].…”