Parikh Parth P, Harahsheh Ehab Y, Dumitrascu Oana M
Mayo Clinic Alix School of Medicine.
Departments of Neurology.
Neurologist. 2023 Jan 1;28(1):46-48. doi: 10.1097/NRL.0000000000000433.
Permanent perioperative vision loss is caused by ischemic optic neuropathy (ION) or central retinal artery occlusion (CRAO). Whereas diffusion restriction of the optic nerve (ON) on brain magnetic resonance imaging has been previously reported in perioperative posterior ION (PION), there are no reports of ON diffusion restriction in patients diagnosed with acute perioperative CRAO. We present a case of perioperative CRAO to highlight this neuroimaging finding for neuroradiologists and neurologists.
A 71-year-old male without vascular risk factors underwent maxillary bilateral antrostomy and septoplasty for chronic sinusitis. Twenty to thirty minutes upon awakening, he complained of painless left eye vision loss. Ophthalmoscopic examination showed retinal whitening, segmented arterioles, and hyperemic disc. Brain MR-diffusion weighted imaging/apparent diffusion coefficient revealed ON diffusion restriction in the proximal segment. Despite attempted reperfusion, left eye remained with no light perception at 6 months. Patients undergoing nonocular surgeries who develop perioperative vision loss related to PION may exhibit ON diffusion restriction but usually have normal ophthalmoscopic findings. CRAO shows retinal whitening, edema, segmentation of arterioles, and cherry red spot on ophthalmoscopy. A recent study reported that ON diffusion restriction in nonperioperative CRAO cases has a sensitivity and specificity of 55% and 70% to 100%. Here, PION was initially considered based on imaging. However, given the neuro-ophthalmic findings, a proximal embolus in the central retinal artery, obstructing its entrance into the proximal ON was deemed more likely.
We highlight that proximal ON diffusion restriction on brain magnetic resonance imaging can be diagnostic of proximal thromboembolic CRAO. Future studies should evaluate the diagnostic utility and accuracy of MR-diffusion weighted imaging/apparent diffusion coefficient in perioperative visual loss.
围手术期永久性视力丧失是由缺血性视神经病变（ION）或视网膜中央动脉阻塞（CRAO）引起的。虽然先前已有围手术期后部ION（PION）患者在脑磁共振成像上出现视神经（ON）扩散受限的报道，但在诊断为急性围手术期CRAO的患者中尚无ON扩散受限的报道。我们报告一例围手术期CRAO病例，以向神经放射科医生和神经科医生强调这一神经影像学发现。
一名71岁无血管危险因素的男性因慢性鼻窦炎接受双侧上颌窦造口术和鼻中隔成形术。苏醒后20至30分钟，他主诉左眼无痛性视力丧失。眼底检查显示视网膜变白、动脉节段化和视盘充血。脑磁共振扩散加权成像/表观扩散系数显示近端节段ON扩散受限。尽管尝试了再灌注治疗，但6个月时左眼仍无光感。接受非眼科手术且发生与PION相关的围手术期视力丧失的患者可能表现出ON扩散受限，但通常眼底检查结果正常。CRAO在眼底检查时表现为视网膜变白、水肿、动脉节段化和樱桃红斑。最近一项研究报告称，非围手术期CRAO病例中ON扩散受限的敏感性和特异性分别为55%和70%至100%。在此，最初根据影像学考虑为PION。然而，鉴于神经眼科检查结果，更有可能的原因是视网膜中央动脉近端有栓子，阻塞了其进入近端ON。
我们强调脑磁共振成像上近端ON扩散受限可诊断近端血栓栓塞性CRAO。未来的研究应评估磁共振扩散加权成像/表观扩散系数在围手术期视力丧失中的诊断效用和准确性。
