González Esther G, Shi Runjie, Tarita-Nistor Luminita, Mandelcorn Efrem D, Mandelcorn Mark S, Steinbach Martin J
Krembil Research Institute, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada.
Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 2S8, Canada.
Vision (Basel). 2018 Apr 13;2(2):19. doi: 10.3390/vision2020019.
For patients with central vision loss and controls with normal vision, we examined the horizontal vestibulo-ocular reflex (VOR) in complete darkness and in the light when enhanced by vision (VVOR). We expected that the visual-vestibular interaction during VVOR would produce an asymmetry in the gain due to the location of the preferred retinal locus (PRL) of the patients. In the dark, we hypothesized that the VOR would not be affected by the loss of central vision. Nine patients (ages 67 to 92 years) and 17 controls (ages 16 to 81 years) were tested in 10-s active VVOR and VOR procedures at a constant frequency of 0.5 Hz while their eyes and head movements were recorded with a video-based binocular eye tracker. We computed the gain by analyzing the eye and head peak velocities produced during the intervals between saccades. In the light and in darkness, a significant proportion of patients showed larger leftward than rightward peak velocities, consistent with a PRL to the left of the scotoma. No asymmetries were found for the controls. These data support the notion that, after central vision loss, the preferred retinal locus (PRL) in eccentric vision becomes the centre of visual direction, even in the dark.
对于中心视力丧失的患者和视力正常的对照组，我们在完全黑暗以及视觉增强时（视觉-前庭眼反射，VVOR）的光照条件下检查了水平前庭眼反射（VOR）。我们预期，由于患者首选视网膜位点（PRL）的位置，VVOR期间的视-前庭相互作用会导致增益不对称。在黑暗中，我们假设VOR不会受到中心视力丧失的影响。对9名患者（年龄67至92岁）和17名对照组（年龄16至81岁）进行了测试，在10秒的主动VVOR和VOR程序中，频率恒定为0.5Hz，同时使用基于视频的双眼眼动追踪仪记录他们的眼睛和头部运动。我们通过分析扫视间隔期间产生的眼睛和头部峰值速度来计算增益。在光照和黑暗条件下，相当一部分患者的向左峰值速度大于向右峰值速度，这与暗点左侧的PRL一致。对照组未发现不对称现象。这些数据支持这样一种观点，即中心视力丧失后，即使在黑暗中，偏心视力中的首选视网膜位点（PRL）也会成为视觉方向的中心。
