VISUAL-VESTIBULAR INTERACTION WITH LOW VISION AIDS

（摘自申请人摘要）许多低视力患者 中心视力受损，但无法成功使用望远镜 尽管理论上从放大中受益。 这可能是因为 使用望远镜的视力恢复受到不稳定性的限制 在不自主的头部运动过程中放大的视网膜图像， 在视觉搜索所必需的协调的眼头运动期间。 视网膜图像稳定性通常由视觉前庭提供， 眼反射（VVOR），由前庭-眼的相互作用产生 具有视觉和预测机制的反射（视觉前庭反射 相互作用VVI）。 使用望远镜的VVOR性能必须 定量适合放大，以避免大量 头部运动时动态视敏度受损。 整体 目的是定量评价视觉前庭功能的机制， 在垂直计划的相互作用，作为有用的视野的决定因素， 在生理性头部运动期间使用望远镜。 眼睛和头部 移动将使用磁搜索线圈测量，并辅以 红外线眼电图 望远镜对垂直方向的影响 VVOR将在以下生理范围内进行定量表征： 视力正常的主动和被动头部速度和频率 低视力的成年人 可预测和不可预测的头部运动将 借助数学建模和模拟进行研究，以便 确定预测的作用，运动传出复制，和其他眼 补充VVI的运动机制。 调查结果将与 视觉引导跟踪的单独测量。 的关系 瞬时垂直视网膜图像滑动速度和动态 视觉敏锐度，将研究有关的观看策略 戴着望远镜 通过研究水平眼和垂直眼， 在不受限制的视觉搜索过程中， 识别最佳视觉搜索策略的特征， 望远镜 修改搜索策略以最小化 还将评估视网膜图像不稳定性和搜索时间。 这些 数据将增强对人类垂直眼球运动的基本理解， 为临床低视力中的一个重要问题提供临床见解。

(Adapted from the applicant's abstract) Many low vision patients have impaired central acuity but cannot successfully use telescopic spectacles despite the theoretical benefit from magnification. This may be because visual rehabilition with telescopic spectacles is limited by instability of the magnified retinal image during involuntary head movements, and during coordinated eye-head movements necessitated by visual search. Retinal image stability is ordinarily provided by the visual-vestibulo- ocular reflex (VVOR), produced by interaction of the vestibulo-ocular reflex with visual and predictive mechanisms (visual vestibular interaction VVI). VVOR performance with telescopic spectacles must be quantitatively appropriate to magnification to avoid substantial impairment of dynamic visual acuity during head movements. The overall aim is to quantitatively evaluate mechanisms of visual-vestibular interaction in the vertical plan, as determinants of useful vision with telescopic spectacles during physiologic head movements. Eye and head movements will be measured using magnetic search coils, supplemented by infrared oculography. The effect of telescopic spectacles on vertical VVOR will be quantitatively characterized in the physiologic range of active and passive head velocities and frequencies, in normally sighted and low vision adults. Predictable and unpredictable head movements will be studied with aid of mathematical modelling and simulation in order to ascertain the role of predictive, motor efference copy, and other ocular motor mechanisms in supplementing VVI. Findings will be correlated with separate measurements of visually guided tracking. The relationship between instantaneous vertical retinal image slip velocity, and dynamic visual acuity, will be studied in relation to viewing strategies employed with telescopic spectacles. By studying horizontal and vertical eye and head movements during unrestrained visual search, experiments will identify characteristics of optimal visual search strategies with telescopic spectacles. Modification of search strategy to minimize retinal image instability and search time will also be evaluated. These data will enhance basic understanding of human vertical eye movements, and provide clinical insight into an important problem in clinical low vision.