He Zheng, Bui Bang V, Vingrys Algis J
Department of Optometry and Vision Sciences, University of Melbourne, Parkville 3010, Victoria, Australia.
Invest Ophthalmol Vis Sci. 2006 Nov;47(11):4872-80. doi: 10.1167/iovs.06-0590.
To evaluate the recovery of retinal function after acute IOP elevation.
The electroretinogram (ERG) was measured before, during, and after IOP increased to 50 and 70 mm Hg at different durations in anesthetized, dark-adapted rats (n = 5-7). Signals were collected for dim and bright flashes (-4.95 and 1.0 log cd . s/m(2)) and analyzed in terms of the photoreceptoral (P3), postreceptoral (P2), and inner retinal (negative scotopic threshold response [nSTR]) responses. Parameters (treatment/baseline, %) were compared across time by using repeated-measures ANOVA and t-tests. The rate of recovery was quantified with a logistic function and compared by bootstrap.
IOP spikes induce greater loss (P < 0.01) and slower recovery (P < 0.001) in the nSTR compared with the P2 and P3 responses. IOP spikes having common integral (pressure x duration, 2100 mm Hg x minutes) for insult gave significantly greater P2 and nSTR dysfunction at the higher pressure (70 vs. 50 mm Hg, nSTR reduced to -2.5% +/- 0.5% vs. 20.3% +/- 6.5%, P < 0.05). The higher pressure also produced significantly slower nSTR recovery (50% recovery time [t(0.5)] 70 vs. 50 mm Hg: 33.1 vs. 21.7 minutes; P < 0.05). At a given IOP (70 mm Hg), t(0.5) showed a linear relationship with duration (15 vs. 30 vs. 60 minutes' exposure: t(0.5) 16.7 vs. 33.1 vs. 63.2 minutes; P < 0.05) and integral.
Ganglion cell function recovers slower than the outer retina after IOP insult, with peak IOP being the principle determinant of functional loss and recovery. For a fixed pressure, functional recovery is linearly related to exposure.
评估急性眼压升高后视网膜功能的恢复情况。
在麻醉、暗适应的大鼠（n = 5 - 7）中，于眼压在不同持续时间内升高至50和70 mmHg之前、期间及之后测量视网膜电图（ERG）。收集暗光和亮光闪烁（-4.95和1.0 log cd·s/m²）的信号，并根据光感受器（P3）、感受器后（P2）和视网膜内层（负暗视阈值反应[nSTR]）反应进行分析。使用重复测量方差分析和t检验在不同时间比较参数（处理/基线，%）。恢复率用逻辑函数进行量化，并通过自助法进行比较。
与P2和P3反应相比，眼压峰值引起nSTR更大程度的损失（P < 0.01）和更慢的恢复（P < 0.001）。具有相同损伤积分（压力×持续时间，2100 mmHg×分钟）的眼压峰值在较高压力（70 vs. 50 mmHg，nSTR降至-2.5%±0.5% vs. 20.3%±6.5%，P < 0.05）时导致P2和nSTR功能障碍明显更严重。较高压力还导致nSTR恢复明显更慢（50%恢复时间[t(0.5)] 70 vs. 50 mmHg：33.1 vs. 21.7分钟；P < 0.05）。在给定眼压（70 mmHg）下，t(0.5)与持续时间（15 vs. 30 vs. 60分钟暴露：t(0.5) 16.7 vs. 33.1 vs. 63.2分钟；P < 0.05）和积分呈线性关系。
眼压损伤后，神经节细胞功能的恢复比视网膜外层慢，眼压峰值是功能损失和恢复的主要决定因素。对于固定压力，功能恢复与暴露时间呈线性相关。
