Zetlan S R, Sponsel W E, Stodtmeister R
Department of Ophthalmology, University of Wisconsin, Madison.
Invest Ophthalmol Vis Sci. 1992 May;33(6):1857-63.
Twenty-three normal adult volunteers underwent single eye visual-evoked potential (VEP) and blue field entoptic studies during suction cup-induced intraocular pressure (IOP) elevation, to determine whether IOP-induced changes in VEP are related to alterations in retinal capillary hemodynamics. VEP pressure tolerance testing through an ascending series of 6-8 IOP levels was carried out using a 7.1 Hz reversing checkerboard grating, with amplitudes averaged by Nicolet Pathfinder. Nineteen of the 23 subjects (83%) showed an increase from baseline in their VEP amplitude at IOP values approximating to central retinal diastolic pressures. All subjects underwent subsequent blue field entoptic hemodynamic studies at each of four IOP values related to their VEP pressure tolerance curve--at baseline IOP, at IOP corresponding to the VEP amplitude peak, and at IOPs corresponding to trough points either side of this peak. Blue field studies were conducted in a masked fashion with pressures generated in semirandom sequence. VEP amplitude pressure tolerance curves were found to vary in strong positive concordance with retinal leukocyte velocity pressure tolerance patterns (P less than 0.001). Leukocyte density initially varied inversely to velocity and VEP amplitude, increasing marginally with initial IOP elevation, but then fell in parallel with velocity at IOP levels exceeding the VEP amplitude peak (P = 0.009). These findings indicate a strong interrelationship between retinal hemodynamics and visual pathway activity as measured by VEP, suggesting that vascular autoregulation may account for the characteristic pattern of the normal VEP pressure tolerance curve.
23名正常成年志愿者在吸盘诱导的眼压（IOP）升高期间接受了单眼视觉诱发电位（VEP）和蓝视标内视现象研究，以确定眼压引起的VEP变化是否与视网膜毛细血管血流动力学改变有关。使用7.1 Hz反转棋盘格光栅通过6 - 8个眼压水平的递增系列进行VEP压力耐受性测试，振幅由Nicolet Pathfinder平均。23名受试者中有19名（83%）在眼压值接近视网膜中央舒张压时，其VEP振幅相对于基线有所增加。所有受试者随后在与他们的VEP压力耐受性曲线相关的四个眼压值下进行了蓝视标内视现象血流动力学研究——在基线眼压、对应VEP振幅峰值的眼压以及该峰值两侧对应谷值的眼压下。蓝视标研究以盲法进行，压力以半随机顺序产生。发现VEP振幅压力耐受性曲线与视网膜白细胞速度压力耐受性模式呈强正相关（P < 0.001）。白细胞密度最初与速度和VEP振幅呈反比变化，随着初始眼压升高略有增加，但在眼压水平超过VEP振幅峰值时与速度平行下降（P = 0.009）。这些发现表明视网膜血流动力学与通过VEP测量的视觉通路活动之间存在很强的相互关系，提示血管自动调节可能解释了正常VEP压力耐受性曲线的特征模式。
