Mukaida Yasuko, Machida Shigeki, Masuda Tomoyuki, Tazawa Yutaka
Department of Ophthalmology, Iwate Medical University School of Medicine, Morioka, Iwate, Japan.
Curr Eye Res. 2004 Jun;28(6):381-9. doi: 10.1080/02713680490503679.
To investigate the relationship between retinal function and histopathology following retinal ischemia-reperfusion in rats.
Retinal ischemia was induced in 27 Sprague-Dawley rats by raising the intraocular pressure for 60- or 90-minutes. Two weeks after the retinal ischemia-reperfusion, ganzfeld stimuli of different luminances (maximum 0.51 log cd-s/m2) were used to elicit full-field ERGs from the right (experimental) and left (control) eyes. The amplitudes of the scotopic b-waves were measured, and intensity-response curves were plotted. The b-wave amplitudes at the initial peak (VbIP), the dip (Vb(dip)), and the maximum stimulus intensity (Vb(max)) were measured. The animals were sacrificed after the ERG recordings to determine the surviving retinal cells in the inner nuclear layer (INL).
The log values of the VbIP, Vb(dip) and Vb(max) were linearly correlated with the number of surviving cells in the INL (r = 0.928, 0.905, and 0.913 for VbIP, Vb(dip) and Vb(max), respectively; p < 0.0001 for each). The slope of the regression line for the Vb(dip) was significantly steeper than that for the VbIP and Vb(max) (p < 0.005). The regression line for the Vb(dip) reached undetectable level of the b-wave (<1 microV) even though approximately 25% of the cells still remained in the INL.
The amplitude of the scotopic b-wave is a sensitive index of the surviving INL cells. However, if one selects the stimulus intensity at the dip, the functional loss would be exaggerated in spite of the presence of cells in the INL.
研究大鼠视网膜缺血再灌注后视网膜功能与组织病理学之间的关系。
通过升高眼压60或90分钟，诱导27只Sprague-Dawley大鼠发生视网膜缺血。视网膜缺血再灌注两周后，使用不同亮度（最大0.51 log cd-s/m2）的全视野刺激，从右眼（实验眼）和左眼（对照眼）引出全视野视网膜电图。测量暗视b波的振幅，并绘制强度-反应曲线。测量初始峰值（VbIP）、波谷（Vb(dip)）和最大刺激强度（Vb(max)）时的b波振幅。在视网膜电图记录后处死动物，以确定内核层（INL）中存活的视网膜细胞数量。
VbIP、Vb(dip)和Vb(max)的对数值与INL中存活细胞的数量呈线性相关（VbIP、Vb(dip)和Vb(max)的r值分别为0.928、0.905和0.913；各p值均<0.0001）。Vb(dip)的回归线斜率明显比VbIP和Vb(max)的回归线斜率更陡（p<0.005）。即使INL中仍有约25%的细胞，Vb(dip)的回归线也达到了b波不可检测水平（<1微伏）。
暗视b波的振幅是INL中存活细胞的敏感指标。然而，如果选择波谷处的刺激强度，尽管INL中存在细胞，功能丧失仍会被夸大。
