Bögli Stefan Yu, Afthinos Maresa, Bertolini Giovanni, Straumann Dominik, Huang Melody Ying-Yu
Department of Neurology University Hospital Zurich, University of Zurich, Switzerland.
Department of Neurology University Hospital Zurich, University of Zurich, Switzerland 2Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland 3Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Switzer.
Invest Ophthalmol Vis Sci. 2016 Apr;57(4):1721-7. doi: 10.1167/iovs.15-18072.
Impairment of visual acuity (VA) can be seen early on in various diseases and has a major impact on patients' daily activities. Zebrafish is an important model for studying visual disorders. We developed a new method in zebrafish larva to easily and precisely measure the VA, which should allow for better estimation of affected vision such as after genetic manipulation or pharmacologic intervention.
We used an optokinetic reflex (OKR) paradigm with a staircase technique to estimate VA of zebrafish larva. Consistent eye displacements were used as the indicator for OKR. We measured VA and determined the dependence of VA on clockwise and counterclockwise horizontal stimulus directions.
Visual acuity in zebrafish larva was estimated to be 0.179 ± 0.013 cyc/deg binocularly and 0.129 ± 0.008 cyc/deg (left eye) and 0.128 ± 0.012 cyc/deg (right eye) monocularly. We found within single subjects spatial frequency thresholds that showed highly significant differences between the two horizontal stimulus directions. Average higher and lower binocular thresholds were 0.181 ± 0.026 and 0.158 ± 0.014 cyc/deg, respectively. Importantly, no correlations were found between spatial frequency thresholds and average median peak slow-phase eye velocities (SPV) of OKR in all experiments.
Consistent eye displacements evoked by OKR stimuli can be used as an indirect measure of VA in zebrafish larva. Conversely, using SPV of OKR to determine VA does not seem to be accurate. With our method, single larva showed significantly different VA depending on stimulus directions, which might reflect asymmetric maturation of retinal and/or visual pathway structures.
在多种疾病早期即可观察到视力（VA）受损，这对患者的日常活动有重大影响。斑马鱼是研究视觉障碍的重要模型。我们开发了一种在斑马鱼幼体中轻松精确测量VA的新方法，这应该有助于更好地评估基因操作或药物干预等情况下受影响的视力。
我们使用带阶梯技术的视动反射（OKR）范式来估计斑马鱼幼体的VA。将一致的眼球位移用作OKR的指标。我们测量了VA，并确定了VA对顺时针和逆时针水平刺激方向的依赖性。
斑马鱼幼体的双眼视力估计为0.179±0.013周/度，单眼视力为0.129±0.008周/度（左眼）和0.128±0.012周/度（右眼）。我们发现，在单个受试者中，空间频率阈值在两个水平刺激方向之间显示出高度显著差异。双眼平均较高和较低阈值分别为0.181±0.026和0.158±0.014周/度。重要的是，在所有实验中，未发现空间频率阈值与OKR的平均中值峰值慢相眼速度（SPV）之间存在相关性。
OKR刺激引起的一致眼球位移可作为斑马鱼幼体VA的间接测量指标。相反，使用OKR的SPV来确定VA似乎不准确。通过我们的方法，单个幼体根据刺激方向显示出显著不同的VA，这可能反映了视网膜和/或视觉通路结构的不对称成熟。
