Jarrell R L, Jones W L
Veterans Administration Medical Center, Albuquerque, New Mexico, USA.
J Am Optom Assoc. 1998 Dec;69(12):759-65.
Recent studies have detailed the prevalence and etiology of ocular complications resulting from coronary artery bypass surgery. Of these, retinal nerve fiber layer infarctions are reported most commonly. The clinical sequelae of nerve infarction may include loss of visual acuity, compromised pupillary function, and visual-field defects (the severity of which may be correlated with the location and extent of the insulted tissue).
A patient who had experienced bilateral juxtapapillary nerve fiber layer infarction with subsequent loss of visual acuity and peripheral visual field was followed postoperatively for more than 6 weeks. Immediately before our examination, he underwent quadruple coronary artery bypass graft surgery.
From the data collected during initial and follow-up examinations, it was determined that the nerve fiber layer infarction was probably the result of a systemic ischemic event during an otherwise uncomplicated surgery. Such events may include hypovolemic blood loss, systemic hypotension during or following surgery, or a host of complications that would prevent adequate perfusion to capillaries in select regions of the eye.
The pathology of bilateral juxatapapillary nerve fiber layer infarction as a result of substantial transient systemic ischemia may be explained by examining the microcirculation of this region of the retina. Due to certain anatomic and physiologic characteristics, the capillaries supplying the peripapillary zone are most susceptible to arterial vascular events such as ischemia. It is important to recognize this clinical presentation in order to rule out other possible causes for decreased visual acuity and field defects in the postoperative coronary bypass surgery patient.
近期研究详细阐述了冠状动脉搭桥手术所致眼部并发症的患病率及病因。其中,视网膜神经纤维层梗死最为常见。神经梗死的临床后遗症可能包括视力丧失、瞳孔功能受损以及视野缺损(其严重程度可能与受损组织的位置和范围相关)。
对一名经历双侧视乳头旁神经纤维层梗死并随后出现视力和周边视野丧失的患者进行了术后6周以上的随访。在我们检查前,他接受了四重冠状动脉搭桥手术。
根据初次及随访检查收集的数据,确定神经纤维层梗死可能是在原本无并发症的手术过程中发生全身性缺血事件的结果。此类事件可能包括低血容量性失血、手术期间或术后的全身性低血压,或一系列会妨碍眼部特定区域毛细血管充分灌注的并发症。
通过检查视网膜该区域的微循环,可解释因大量短暂全身性缺血导致双侧视乳头旁神经纤维层梗死的病理情况。由于某些解剖和生理特征,供应视乳头周围区域的毛细血管最易受到诸如缺血等动脉血管事件的影响。认识到这种临床表现对于排除冠状动脉搭桥手术术后患者视力下降和视野缺损的其他可能原因很重要。