School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
Department of Optometry, Asia University, Taichung, Taiwan.
PLoS One. 2022 Apr 29;17(4):e0249052. doi: 10.1371/journal.pone.0249052. eCollection 2022.
Vision is critical for children's development. However, prevalence of visual impairment (VI) is high in students with special educational needs (SEN). Other than VI, SEN students are prone to having functional deficits. Whether visual problems relate to these functional deficits is unclear. This study aimed to assess the impact of vision on visual processing functions and balance in SEN students through a community service.
Visual acuity (VA) and contrast sensitivity were measured in a total of 104 (aged 14.3±4.3) SEN students as the visual outcomes, followed by retinoscopy. Visual processing function assessment included facial expression recognition by card matching examiner's facial expression matching, and visual orientation recognition. Dynamic balance, by Timed Up and Go test, and static standing balance (postural sway in double-legged standing with feet-together and tandem-stance for open-eye and closed-eye conditions) were assessed. Static balance was presented in terms of the maximal medial-lateral and antero-posterior sways.
Of the 104 students, 62 (59.6%) were classified as visually impaired according to WHO classification of visual impairment based on presenting distance acuity. Ocular problems (e.g. optic nerve anomaly, uncorrected/ under-corrected refractive errors) and neurological anomalies were the major causes of vision loss. VA was positively associated with visual processing functions (all p ≤ 0.01), as SEN students with better vision tended to perform better in visual orientation and facial expression recognition tasks, as well as dynamic balance function (p = 0.04). For the static balance, postural sway and VA showed a positive relationship under open-eye and tandem stance conditions. However, the relationship between postural sway and VA became negative under closed-eye and tandem stance conditions.
This study found a high prevalence of SEN students with visual impairment, in which many of them were undetected. Optometric examination is important to improve their visual function to minimize the effect of vision on functional performance. Vision is critical in visual processing as well as playing an important role in maintaining balance in SEN students.
视力对儿童的发展至关重要。然而，有特殊教育需求的学生（SEN）中视力障碍（VI）的患病率很高。除 VI 外，SEN 学生还容易出现功能缺陷。视觉问题是否与这些功能缺陷有关尚不清楚。本研究旨在通过社区服务评估视力对 SEN 学生视觉加工功能和平衡的影响。
共测量了 104 名（年龄 14.3±4.3 岁）SEN 学生的视力（VA）和对比敏感度作为视觉结果，然后进行视网膜检查。视觉加工功能评估包括面部表情识别，通过卡片匹配检查者的面部表情匹配，以及视觉定向识别。动态平衡通过计时起立行走测试进行评估，静态站立平衡（双脚并拢和前后脚站立的闭眼和睁眼条件下的姿势摆动）。静态平衡以最大的内外摆动和前后摆动表示。
在 104 名学生中，根据世卫组织基于表现距离视力的视力损伤分类标准，有 62 名（59.6%）学生被归类为视力受损。眼部问题（例如视神经异常、未矫正/欠矫屈光不正）和神经异常是视力丧失的主要原因。VA 与视觉加工功能呈正相关（均 p≤0.01），因为视力较好的 SEN 学生在视觉定向和面部表情识别任务以及动态平衡功能方面表现更好（p=0.04）。对于静态平衡，在睁眼和前后脚站立条件下，姿势摆动和 VA 呈正相关。然而，在闭眼和前后脚站立条件下，姿势摆动和 VA 之间的关系变为负相关。
本研究发现 SEN 学生视力障碍的患病率很高，其中许多学生未被发现。眼科检查对于改善他们的视觉功能以最大程度地减少视力对功能表现的影响非常重要。视力对 SEN 学生的视觉加工和维持平衡都很重要。
