Tsutsumi Satoshi, Rhoton Albert L
Department of Neurological Surgery, University of Florida, Gainesville, Florida 32610, USA.
Neurosurgery. 2006 Oct;59(4):870-8; discussion 878-9. doi: 10.1227/01.NEU.0000232654.15306.4A.
To define the microsurgical anatomy of the central retinal artery (CRA) and to provide a guide to avoiding damage to it during surgery.
The anatomic characteristics of the CRA and small arteries distributed to the optic sheath were examined in 109 orbits. The origin, course, and site of entry of the artery into the optic sheath and the distance between the orbital apex and the site of entry into the sheath were examined.
The CRAs originated directly from the intraorbital ophthalmic artery or in a common trunk with a posterior ciliary or a muscular branch. The CRAs most commonly originated on the inferomedial side of the ophthalmic artery an average of 8.4 mm distal to the orbital end of the optic canal. They penetrated the optic sheath near the junction of the middle and anterior thirds of the length of the intraorbital optic nerve an average of 18.6 mm distal to the optic canal. More than 70% of CRAs penetrated near the midline of the lower surface of the optic sheath, 21% entered the inferomedial surface, and 7% the inferolateral or lateral surface of the optic sheath. Only one CRA gave off a branch before penetrating the nerve.
The CRA is at risk of being damaged or occluded during procedures involving a large part of the orbit. Procedures directed along the lower half of the proximal two-thirds of the optic sheath have the greatest risk of interrupting the artery.
明确视网膜中央动脉（CRA）的显微外科解剖结构，并为手术中避免损伤该动脉提供指导。
在109个眼眶中检查CRA及分布至视神经鞘的小动脉的解剖特征。检查动脉的起源、走行、进入视神经鞘的部位以及眶尖与进入鞘的部位之间的距离。
CRA直接起源于眶内眼动脉，或与睫状后动脉或肌支共干起源。CRA最常见于眼动脉的内下侧，平均位于视神经管眶端远端8.4mm处。它们在眶内视神经长度前三分之二与中三分之一交界处附近穿入视神经鞘，平均位于视神经管远端18.6mm处。超过70%的CRA在视神经鞘下表面中线附近穿入，21%进入内下表面，7%进入视神经鞘的外下或外侧表面。只有一条CRA在穿入神经前发出分支。
在涉及眼眶大部分区域的手术过程中，CRA有受损或闭塞的风险。沿着视神经鞘近端三分之二下半部进行的手术中断动脉的风险最大。
