Weinberg D V, Egan K M, Seddon J M
Department of Ophthalmology, Northwestern University Medical School, Chicago, IL 60611.
Ophthalmology. 1993 Jan;100(1):31-6. doi: 10.1016/s0161-6420(13)31702-3.
Recently, there has been renewed interest in the orientation of the crossing retinal vessels at arteriovenous intersections, particularly as it relates to the risk of branch vein occlusion. Little is known about the distribution of the two types of crossings in the normal retina.
The authors studied standard fundus photographs of 51 subjects without retinal disease. Arteriovenous crossings were analyzed for fundus location and relative orientation of the crossing vessels (vein-posterior or vein-anterior).
In the superotemporal quadrant, crossings were distributed closer to the optic disc (P < 0.001), and a greater proportion of crossings were vein-posterior (P = 0.01) than in the inferotemporal quadrant. As a result, within a 3-disc diameter (DD) radius of the optic disc, there were significantly more vein-posterior crossings in the superotemporal than in the inferotemporal quadrant (P < 0.001).
These findings further define normal retinal vascular anatomy and may explain the predilection for branch retinal vein occlusions to occur in the superotemporal quadrant.
最近，人们对视网膜动静脉交叉处血管的走行方向重新产生了兴趣，尤其是其与视网膜分支静脉阻塞风险的关系。对于正常视网膜中这两种交叉类型的分布情况，人们了解甚少。
作者研究了51名无视网膜疾病受试者的标准眼底照片。分析了动静脉交叉处的眼底位置以及交叉血管的相对走行方向（静脉在后或静脉在前）。
在颞上象限，交叉处分布得更靠近视盘（P < 0.001），且与颞下象限相比，静脉在后的交叉处比例更高（P = 0.01）。因此，在视盘直径3倍（DD）范围内，颞上象限静脉在后的交叉处明显多于颞下象限（P < 0.001）。
这些发现进一步明确了正常视网膜血管解剖结构，并可能解释视网膜分支静脉阻塞好发于颞上象限的原因。
