O'Connell Caitlin, Mahboobin Arash, Drexler Scott, Redfern Mark S, Perera Subashan, Nau Amy C, Cham Rakié
Department of Bioengineering, University of Pittsburgh, 439 Benedum Hall, 3700 O'Hara Street, Pittsburgh, PA, 15261, USA.
UPMC Eye Center, Department of Ophthalmology, University of Pittsburgh, 203 Lothrop Street, Pittsburgh, PA, 15213, USA.
Exp Brain Res. 2017 Nov;235(11):3261-3270. doi: 10.1007/s00221-017-5045-x. Epub 2017 Aug 1.
Vision impairments such as age-related macular degeneration (AMD) and glaucoma are among the top risk factors for geriatric falls and falls-related injuries. AMD and glaucoma lead to loss of the central and peripheral visual fields, respectively. This study utilized a custom contact lens model to occlude the peripheral or central visual fields in healthy adults, offering a novel within-subject approach to improve our understanding of the etiology of balance impairments that may lead to an increased fall risk in patients with visual field loss. Two dynamic posturography tests, including an adapted version of the Sensory Organization Test and a virtual reality environment with the visual scene moving sinusoidally, were used to evaluate standing balance. Balance stability was quantified by displacement and time-normalized path length of the center of pressure. Nine young and eleven older healthy adults wore visual field occluding contact lenses during posturography assessments to compare the effects of acute central and peripheral visual field occlusion. The results found that visual field occlusion had greater impact on older adults than young adults, specifically when proprioceptive cues are unreliable. Furthermore, the results suggest that both central and peripheral visions are important in postural control; however, peripheral vision may be more sensitive to movement in the environment.
诸如年龄相关性黄斑变性（AMD）和青光眼等视力障碍是老年人跌倒及跌倒相关损伤的主要风险因素。AMD和青光眼分别导致中心视野和周边视野丧失。本研究利用定制的隐形眼镜模型来遮挡健康成年人的周边或中心视野，提供了一种新颖的受试者内研究方法，以增进我们对可能导致视野丧失患者跌倒风险增加的平衡障碍病因的理解。两项动态姿势描记测试，包括改良版的感觉统合测试和视觉场景呈正弦运动的虚拟现实环境，用于评估站立平衡。平衡稳定性通过压力中心的位移和时间归一化路径长度来量化。九名年轻健康成年人和十一名年长健康成年人在姿势描记评估期间佩戴遮挡视野的隐形眼镜，以比较急性中心视野和周边视野遮挡的影响。结果发现，视野遮挡对老年人的影响比对年轻人更大，尤其是在本体感觉线索不可靠时。此外，结果表明，中心视野和周边视野在姿势控制中都很重要；然而，周边视野可能对环境中的运动更敏感。
