Genevois Olivier, Paques Michel, Simonutti Manuel, Sercombe Richard, Seylaz Jacques, Gaudric Alain, Brouland Jean-Philippe, Sahel José, Vicaut Eric
Microcirculation Laboratory, Hôpital Fernand Widal, Paris France.
Invest Ophthalmol Vis Sci. 2004 Feb;45(2):594-600. doi: 10.1167/iovs.03-0764.
To describe the time course of microvascular changes after transient branch retinal vein occlusion (BRVO) in rats.
BRVO was induced in pigmented rats by focal laser photocoagulation. The subsequent changes in the retinal angiogram were followed up, both in vivo by confocal scanning laser ophthalmoscopy and ex vivo by confocal microscopy.
At day 1, capillary closure affected the three microvessel layer differentially, the intermediary layer being the most affected. Collateral veins, which were initiated by the dilation of deep-layer venules, pursued their course below adjacent arteries. These microvascular changes peaked between days 1 and 3. After recanalization at day 3, microvascular changes regressed gradually but incompletely, and at day 30 capillary closure and venule dilation persisted.
Transient occlusion of a retinal vein in rats leads to short- and long-term microvascular remodeling upstream of the occlusion site. This study describes a model for the tridimensional arrangement of retinal microvessel that accounts for the topography of the early capillary closure and collateral vessel formation that occur after BRVO. In the long term, these changes regressed incompletely, with recanalization of the occluded vein, suggesting that after a short period of occlusion, microvascular changes may become at least partially independent of flow. Despite the intrinsically limited applicability of this model to human vein occlusion, the results suggest that even if therapeutic decompression of an occluded vein is performed early, it may not reverse capillary dropout completely.
描述大鼠视网膜分支静脉阻塞（BRVO）后微血管变化的时间进程。
通过聚焦激光光凝诱导有色大鼠发生BRVO。通过共聚焦扫描激光检眼镜在体内以及通过共聚焦显微镜在体外对随后的视网膜血管造影变化进行随访。
在第1天，毛细血管闭塞对三个微血管层的影响存在差异，中间层受影响最大。由深层小静脉扩张引发的侧支静脉在相邻动脉下方延伸。这些微血管变化在第1天至第3天达到峰值。在第3天再通后，微血管变化逐渐消退但不完全消退，并且在第30天毛细血管闭塞和小静脉扩张仍然存在。
大鼠视网膜静脉的短暂闭塞导致闭塞部位上游的短期和长期微血管重塑。本研究描述了一种视网膜微血管三维排列的模型，该模型解释了BRVO后早期毛细血管闭塞和侧支血管形成的地形学。从长期来看，这些变化不完全消退，闭塞静脉再通，这表明在短暂闭塞后，微血管变化可能至少部分地与血流无关。尽管该模型对人类静脉闭塞的内在适用性有限，但结果表明，即使早期对闭塞静脉进行治疗性减压，也可能无法完全逆转毛细血管丢失。
