Morgan W H, Yu D Y, Alder V A, Cringle S J, Cooper R L, House P H, Constable I J
The Lions Eye Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, Nedlands, Australia.
Invest Ophthalmol Vis Sci. 1998 Jul;39(8):1419-28.
To measure the effects of cerebrospinal fluid pressure (CSFp) on retrolaminar tissue pressure (RLTp) and the translaminar pressure gradient (TLPG), particularly at low CSFp, which is the normal situation in erect posture.
Micropipettes coupled to a servonull pressure system were passed into eyes of anesthetized dogs to the optic disc and advanced in steps through the lamina cribrosa to the optic nerve subarachnoid space (ONSAS), while pressure measurements were taken. Cerebrospinal fluid pressure and intraocular pressure (IOP) were monitored and controlled. The TLPG was measured at varying IOPs and CSFps. The RLTp and ONSAS pressure (ONSASp) were measured at varying CSFps. In separate experiments, the optic nerve dura was incised, and pressure measurements were taken across the pia mater.
The TLPG was strongly correlated to the difference between IOP and CSFp (r=0.93; n=18) when CSFp was more than zero. Mean RLTp was 3.7+/-0.2 mm Hg (SEM; n=15) when CSFp was 0 mm Hg. The ONSASp and RLTp were largely dependent on the presence of CSFp higher than break point pressures of -0.5 mm Hg and 1.33 mm Hg, respectively. However, below these break points, RLTp (slope 0.07) and ONSASp (slope 0.18) were little influenced by CSFp. Separate measurements across the pia mater revealed that 95% of the pressure drop occurred within 100 microm of the pial surface.
The TLPG and RLTp are dependent on CSFp when CSFp is more than -0.5 mm Hg. Below this level, there is no hydrostatic continuity between the intracranial and optic nerve subarachnoid space. In this range, RLTp is stable and is little influenced by CSFp changes.
测量脑脊液压力（CSFp）对板后组织压力（RLTp）和跨板压力梯度（TLPG）的影响，特别是在低脑脊液压力时，这是直立姿势下的正常情况。
将与伺服零压力系统相连的微吸管插入麻醉犬的眼内至视盘，并逐步穿过筛板进入视神经蛛网膜下腔（ONSAS），同时进行压力测量。监测并控制脑脊液压力和眼内压（IOP）。在不同的眼内压和脑脊液压力下测量跨板压力梯度。在不同的脑脊液压力下测量板后组织压力和视神经蛛网膜下腔压力（ONSASp）。在单独的实验中，切开视神经硬膜，并在软脑膜上进行压力测量。
当脑脊液压力大于零时，跨板压力梯度与眼内压和脑脊液压力之差密切相关（r = 0.93；n = 18）。当脑脊液压力为0 mmHg时，平均板后组织压力为3.7±0.2 mmHg（标准误；n = 15）。视神经蛛网膜下腔压力和板后组织压力在很大程度上分别取决于脑脊液压力高于-0.5 mmHg和1.33 mmHg的断点压力。然而，在这些断点以下，板后组织压力（斜率0.07）和视神经蛛网膜下腔压力（斜率0.18）受脑脊液压力的影响很小。在软脑膜上的单独测量显示，95%的压力降发生在软脑膜表面100微米范围内。
当脑脊液压力大于-0.5 mmHg时，跨板压力梯度和板后组织压力取决于脑脊液压力。低于此水平，颅内和视神经蛛网膜下腔之间不存在流体静力连续性。在此范围内，板后组织压力稳定，受脑脊液压力变化的影响很小。
