同义视野缺陷代表中风后最常见的视野丧失类型,影响近30%的单侧交叉后脑损伤患者。这篇综述旨在收集中风后视野丧失的生物力学变化的可用证据。
进行了系统评价,包括随机对照试验,队列研究,前后研究和病例对照研究。研究包括调查眼睛的成人和儿科参与者,头部,包括视觉探索任务中中风后视野丧失中的身体运动。搜索词包括一系列MESH术语以及与中风有关的替代术语,视野损失,偏盲,视觉功能和扫描行为。文章由两位作者独立选择。数据由一位作者提取,并经过一秒钟的验证。使用适合研究设计的清单评估所有纳入的文章的偏倚风险。
36篇文章(1123名参与者)被纳入总体综述(Kappa0.863),并被归类为模拟或真实视野丧失(通常为偏盲)。与正常表现相比,七项研究确定了模拟偏盲的生物力学改变。29项研究详述了眼睛,真实偏盲的头部和身体运动参数。偏视参与者和模拟偏视的健康成年人在各种固定和扫视参数方面与对照组显着不同,如固定次数和持续时间增加所示。扫视次数和持续时间以及平均扫视幅度较短的扫描路径长度。在模拟偏盲的情况下,参与者始终偏向于有视力的视野,而真正的偏盲者的注视行为偏向于盲区的方向。
有相当多的证据表明,在真正的偏盲和患有模拟偏盲的健康成年人中,眼球运动发生了改变。在视觉探索的自然主义任务中的成功表现似乎与视觉探索行为的补偿机制有关,即,扫视的幅度和峰值速度增加,横向扩大眼球运动的分布,扫视的整体分布转移到盲区。这篇综述强调了缺乏报告偏盲的头部和其他身体运动参数的研究。需要使用稳健的方法和涉及卒中后视野丧失的参与者的大样本量的进一步研究。
PROSPEROCRD42020194403。
Homonymous visual field defects represent the most frequent type of visual field loss after stroke, affecting nearly 30% of individuals with unilateral post-chiasmal brain damage. This
review aimed to gather the available evidence on the biomechanical changes to visual field loss following stroke.
A systematic
review was conducted inclusive of randomised controlled trials, cohort studies, before-after studies and case-controlled studies. Studies including adult and paediatric participants that investigated eye, head, or body movements in post-stroke visual field loss during visual exploration tasks were included. Search terms included a range of MESH terms as well as alternative terms relating to stroke, visual field loss, hemianopia, visual functions and scanning behaviour. Articles were selected by two authors independently. Data were extracted by one author and verified by a second. All included articles were assessed for risk of bias using checklists appropriate to the study design.
Thirty-six articles (1123 participants) were included in the overall
review (Kappa 0.863) and categorised into simulated or true visual field loss (typically hemianopia). Seven studies identified the biomechanical alterations to simulated hemianopia compared to normal performance. Twenty-nine studies detailed eye, head and body movement parameters in true hemianopia. Hemianopic participants and healthy adults with simulated hemianopia differed significantly from controls in various fixation and saccade parameters as indicated by increased number and duration of fixations, number and duration of saccades and scan path length with shorter mean saccadic amplitude. Under simulated hemianopia, participants were consistently biased towards the sighted visual field while gaze behaviour in true hemianopia was biased in the direction of the blind hemifield.
There is considerable evidence on the altered eye movements that occur in true hemianopia and in healthy adults with simulated
hemianopia. Successful performance in naturalistic tasks of visual exploration appears to be related to compensatory mechanisms of visual exploratory behaviour, namely, an increase in the amplitude and peak velocity of saccades, widening horizontally the distribution of eye movements, and a shift of the overall distribution of saccades into the blind field. This
review highlights the lack of studies reporting head and other body movement parameters in
hemianopia. Further studies with robust methodology and large sample sizes involving participants with post-stroke visual field loss are needed.
PROSPERO CRD42020194403.