Al Othman Bayan A, Naser Maryam, Kini Ashwini T, Lee Andrew G
Department of Ophthalmology (BAAO, ATK, AGL), Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas; Department of Ophthalmology (MN), USC Roski Eye Institute, Keck Medicine of USC, Los Angeles, California; Departments of Ophthalmology (AGL), Neurology, and Neurosurgery, Weill Cornell Medicine, New York, New York; Department of Ophthalmology (AGL), University of Texas Medical Branch, Galveston, Texas; Department of Ophthalmology (AGL), University of Texas MD Anderson Cancer Center, Houston, Texas; Department of Ophthalmology (AGL), Texas A and M College of Medicine, Bryan, Texas; and Department of Ophthalmology (AGL), The University of Iowa Hospitals and Clinics, Iowa City, Iowa.
J Neuroophthalmol. 2021 Mar 1;41(1):e114-e115. doi: 10.1097/WNO.0000000000000897.
Shock-induced anterior ischemic optic neuropathy (SIAION) is a known type of optic neuropathy in patients who experienced shock related to different etiologies such as anemia and severe intradialytic hypotension like in our patient. Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common acute unilateral known type of optic neuropathy in older patients with vasculopathic risk factors such as hypertension, diabetes mellitus, and obstructive sleep apnea. Although SIAION and NAION are similar optic neuropathies due to ischemia and, in particular, hypotension, they may have different pathogenic mechanisms (e.g., acute shock or intradialytic hypotension vs nocturnal hypotension), laterality (e.g., unilateral vs bilateral), and severity (e.g., light perception or worse vision). We presented a case with restricted diffusion on the apparent diffusion coefficient and the diffusion weighted imaging confined to the optic disc head in a patient with pallid edema after intradialytic hypotension. Although DWI of the optic nerve is neither 100% specific nor 100% sensitive for ischemia, we believe that restricted diffusion of the optic nerve head in our case is a clinico-radiologic correlate to pallid edema in SIAION.
休克诱发的前部缺血性视神经病变（SIAION）是一种已知类型的视神经病变，见于经历过与不同病因相关休克的患者，如贫血以及像我们的患者那样严重的透析中低血压。非动脉炎性前部缺血性视神经病变（NAION）是老年患者中最常见的急性单侧已知类型的视神经病变，这些患者具有血管病变风险因素，如高血压、糖尿病和阻塞性睡眠呼吸暂停。尽管SIAION和NAION由于缺血，特别是低血压，是相似的视神经病变，但它们可能具有不同的致病机制（例如，急性休克或透析中低血压与夜间低血压）、单侧性（例如，单侧与双侧）和严重程度（例如，光感或更差的视力）。我们报告了一例透析中低血压后出现苍白性水肿的患者，其表观扩散系数和扩散加权成像上的扩散受限局限于视盘头。尽管视神经的扩散加权成像对缺血既不是100%特异的也不是100%敏感的，但我们认为在我们的病例中视神经头的扩散受限是SIAION中苍白性水肿的临床-放射学关联。
