兔眼表面应用丙美卡因与巩膜静脉压
Topical proparacaine and episcleral venous pressure in the rabbit.
作者信息
Zamora David O, Kiel Jeffrey W
机构信息
Department of Ophthalmology, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
出版信息
Invest Ophthalmol Vis Sci. 2009 Jun;50(6):2949-52. doi: 10.1167/iovs.08-3048. Epub 2009 Jan 17.
PURPOSE
To determine the effect of proparacaine-induced topical anesthesia on episcleral venous pressure (EVP).
METHODS
In anesthetized rabbits (n = 11), EVP was measured with a servonull micropressure system, with glass pipettes with 2- to 3-microm tips used to cannulate episcleral veins. Additional measurements included arterial, intraocular, and orbital venous pressures obtained by direct cannulation, to assess the ocular pressure gradients, and carotid blood flow and heart rate, to verify preparation stability. The protocol entailed 5 to 10 minutes of stable baseline recording followed by topical application of proparacaine (0.5%, 10 microL) with continued measurements for another 5 to 15 minutes.
RESULTS
Baseline EVP without topical anesthesia was 12.3 +/- 1.1 mm Hg. EVP decreased significantly to 8.7 +/- 0.9 mm Hg within minutes after application of proparacaine. A small decrease also occurred in intraocular pressure. All other measured variables were unchanged.
CONCLUSIONS
These results suggest that the episcleral circulation is under tonic neural control and that either an upstream resistance site is under tonic vasodilatory control or a downstream site is under vasoconstrictor control.
目的
确定丙美卡因诱导的表面麻醉对巩膜静脉压（EVP）的影响。
方法
在麻醉的兔子（n = 11）中，使用伺服零位微压系统测量EVP，用尖端为2至3微米的玻璃移液管插入巩膜静脉。额外的测量包括通过直接插管获得的动脉、眼内和眶静脉压，以评估眼压梯度，以及颈动脉血流和心率，以验证准备状态的稳定性。实验方案包括5至10分钟的稳定基线记录，随后局部应用丙美卡因（0.5%，10微升）并继续测量5至15分钟。
结果
未进行表面麻醉时的基线EVP为12.3±1.1毫米汞柱。应用丙美卡因后数分钟内，EVP显著降至8.7±0.9毫米汞柱。眼压也有小幅下降。所有其他测量变量均未改变。
结论
这些结果表明，巩膜循环受紧张性神经控制，要么上游阻力部位受紧张性血管舒张控制，要么下游部位受血管收缩控制。
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