Henderson Amanda D, Jiang Hong, Wang Jianhua
1Wilmer Eye Institute, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Wilmer 233, Baltimore, MD 21231 USA.
2Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 900 NW 17th Street, Miami, FL 33136 USA.
Eye Vis (Lond). 2019 Jan 6;6:3. doi: 10.1186/s40662-018-0126-x. eCollection 2019.
Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common cause of acute optic neuropathy in patients over 50 years of age, and many affected individuals are left with permanent visual deficits. Despite the frequency of NAION and its often devastating effects on vision, no effective treatment has been established. Further understanding of the acute vascular effects in NAION, using advanced ophthalmic imaging techniques like the retinal function imager, may shed light on potential treatment targets.
Five patients with acute NAION underwent retinal functional imaging within 2 weeks of the onset of their visual symptoms, and at 1 month and 3 months after onset. Average arteriolar and venular blood flow velocities were calculated for each eye at each time point. The Wilcoxon rank sum test was used to compare blood flow velocity results with a normative database.
The average arteriolar blood flow velocity in the normative group was 3.8 mm/s, and the average venular blood flow velocity was 3.0 mm/s, versus 4.1 mm/s and 2.7 mm/s, respectively, in the NAION-affected group at presentation. Average arteriolar blood flow increased slightly to 4.2 mm/s one month after the acute NAION event, then decreased to 3.8 mm/s three months after the event. Average venular blood flow velocity was 2.8 mm/s 1 month after the NAION event and 2.7 mm/s 3 months after the event. Differences in blood flow velocity between the NAION-affected and control groups were not statistically significant at any time point; however, there was a trend toward increasing blood flow velocity initially after an NAION, with a decrease over time.
This study demonstrates the feasibility of retinal function imaging to quantify macular blood flow velocity in patients with acute NAION. There were no statistically significant differences in blood flow velocity detected between NAION-affected eyes and healthy controls at any of the time points examined; however, there was a trend toward an increase in both arteriolar and venular BFV subacutely, then a decrease in the chronic phase after NAION, which could be suggestive of a mechanism of attempted compensation in the setting of acute ischemia.
非动脉炎性前部缺血性视神经病变（NAION）是50岁以上患者急性视神经病变的最常见原因，许多患者会留下永久性视力缺陷。尽管NAION很常见，且往往对视力造成严重损害，但尚未确立有效的治疗方法。使用视网膜功能成像仪等先进眼科成像技术进一步了解NAION中的急性血管效应，可能有助于揭示潜在的治疗靶点。
5例急性NAION患者在视觉症状出现后2周内、发病后1个月和3个月接受视网膜功能成像。计算每个时间点每只眼睛的平均小动脉和小静脉血流速度。采用Wilcoxon秩和检验将血流速度结果与标准数据库进行比较。
正常组平均小动脉血流速度为3.8毫米/秒，平均小静脉血流速度为3.0毫米/秒，而NAION受累组在就诊时分别为4.1毫米/秒和2.7毫米/秒。急性NAION事件发生后1个月，平均小动脉血流略有增加至4.2毫米/秒，然后在事件发生后3个月降至3.8毫米/秒。NAION事件发生后1个月，平均小静脉血流速度为2.8毫米/秒，事件发生后3个月为2.7毫米/秒。在任何时间点，NAION受累组与对照组之间的血流速度差异均无统计学意义；然而，NAION发作后最初有血流速度增加的趋势，随后随时间下降。
本研究证明了视网膜功能成像在量化急性NAION患者黄斑血流速度方面的可行性。在所检查的任何时间点，NAION受累眼与健康对照之间的血流速度均无统计学显著差异；然而，在NAION发作后，小动脉和小静脉血流速度均有亚急性增加的趋势，然后在慢性期下降，这可能提示急性缺血情况下的一种代偿机制。
