Grunwald J E, Iannaccone A, DuPont J
Department of Ophthalmology, Scheie Eye Institute, School of Medicine, University of Pennsylvania, Philadelphia 19104, USA.
Br J Ophthalmol. 1999 Feb;83(2):162-7. doi: 10.1136/bjo.83.2.162.
To assess the effects of the nitric oxide donor 5-isosorbide mononitrate (ISMO) on blood flow in the optic nerve head (ON flow) and choroid (Ch flow).
Laser Doppler flowmetry was used to measure ON flow and Ch flow in 12 normal subjects by aiming the laser beam at the fovea and at the temporal rim, respectively. In a double masked, randomised, crossover design, each subject received orally on separate days either 20 mg of 5-isosorbide mononitrate (ISMO) or placebo. Ch flow and ON flow were determined monocularly at baseline and 1 hour after dosing. In the last six subjects, additional measurements were obtained at 3 hours. Mean arterial blood pressure (BPm), heart rate, and intraocular pressure (IOP) were monitored, and ocular perfusion pressure (PP) was estimated.
No significant changes in ON flow, PP, IOP, or BPm were observed following placebo. Following ISMO, ON flow increased from baseline by 19.8% (SEM 9.3%) at 1 hour (paired t test, p = 0.058) and by 33.1% (7.5%) at 3 hours (p = 0.007). Compared with the changes following placebo, statistically significant increases in ON flow were observed both at 1 (p = 0.050) and 3 hours (p = 0.041) after ISMO treatment. Compared with placebo, PP decreased significantly 1 hour after ISMO dosing (p = 0.039), mainly as a function of reduced BPm. A significant inverse correlation (R = -0.618; p = 0.032) was observed between the percentage changes in PP and ON flow 1 hour following ISMO administration, but not after placebo. No significant change in foveal Ch flow was documented.
These results suggest that, in normal subjects, ISMO increases significantly ON flow but not Ch flow. The inverse correlation observed between PP and ON flow suggests that the same mechanism(s) responsible for systemic vasodilatation and blood pressure decrease may also cause the ON flow increase.
评估一氧化氮供体5-单硝酸异山梨酯（ISMO）对视神经乳头血流（ON血流）和脉络膜血流（Ch血流）的影响。
通过将激光束分别对准中央凹和颞侧边缘，使用激光多普勒血流仪测量12名正常受试者的ON血流和Ch血流。采用双盲、随机、交叉设计，每位受试者在不同日期口服20毫克5-单硝酸异山梨酯（ISMO）或安慰剂。在给药前和给药后1小时单眼测定Ch血流和ON血流。在最后6名受试者中，于3小时时进行额外测量。监测平均动脉血压（BPm）、心率和眼压（IOP），并估算眼灌注压（PP）。
服用安慰剂后，未观察到ON血流、PP、IOP或BPm有显著变化。服用ISMO后，ON血流在1小时时较基线增加19.8%（标准误9.3%）（配对t检验，p = 0.058），在3小时时增加33.1%（7.5%）（p = 0.007）。与服用安慰剂后的变化相比，ISMO治疗后1小时（p = 0.050）和3小时（p = 0.041）时ON血流均有统计学显著增加。与安慰剂相比，ISMO给药后1小时PP显著降低（p = 0.039），主要是由于BPm降低。ISMO给药后1小时，PP变化百分比与ON血流之间观察到显著负相关（R = -0.618；p = 0.032），而服用安慰剂后未观察到这种相关性。未记录到中央凹Ch血流有显著变化。
这些结果表明，在正常受试者中，ISMO可显著增加ON血流，但不增加Ch血流。PP与ON血流之间观察到的负相关表明，导致全身血管舒张和血压降低的相同机制可能也会引起ON血流增加。
