Gür Güngör Sirel, Akman Ahmet, Sarıgül Sezenöz Almila, Tanrıaşıkı Gülşah
Başkent University Faculty of Medicine, Department of Ophthalmology, Ankara, Turkey.
Turk J Ophthalmol. 2016 Dec;46(6):274-276. doi: 10.4274/tjo.49358. Epub 2016 Dec 1.
The presence of retinal nerve fiber layer (RNFL) split bundles was recently described in normal eyes scanned using scanning laser polarimetry and by histologic studies. Split bundles may resemble RNFL loss in healthy eyes. The aim of our study was to determine the prevalence of nerve fiber layer split bundles in healthy people.
We imaged 718 eyes of 359 healthy persons with the spectral domain optical coherence tomography in this cross-sectional study. All eyes had intraocular pressure of 21 mmHg or less, normal appearance of the optic nerve head, and normal visual fields (Humphrey Field Analyzer 24-2 full threshold program). In our study, a bundle was defined as 'split' when there is localized defect not resembling a wedge defect in the RNFL deviation map with a symmetrically divided RNFL appearance on the RNFL thickness map. The classification was performed by two independent observers who used an identical set of reference examples to standardize the classification.
Inter-observer consensus was reached in all cases. Bilateral superior split bundles were seen in 19 cases (5.29%) and unilateral superior split was observed in 15 cases (4.16%). In 325 cases (90.52%) there was no split bundle.
Split nerve fiber layer bundles, in contrast to single nerve fiber layer bundles, are not common findings in healthy eyes. In eyes with normal optic disc appearance, especially when a superior RNFL defect is observed in RNFL deviation map, the RNLF thickness map and graphs should also be examined for split nerve fiber layer bundles.
近期在使用扫描激光偏振仪扫描的正常眼睛以及组织学研究中发现了视网膜神经纤维层（RNFL）分裂束。分裂束在健康眼睛中可能类似于RNFL缺失。我们研究的目的是确定健康人群中神经纤维层分裂束的患病率。
在这项横断面研究中，我们使用光谱域光学相干断层扫描对359名健康人的718只眼睛进行了成像。所有眼睛的眼压均在21 mmHg或以下，视神经乳头外观正常，视野正常（Humphrey视野分析仪24-2全阈值程序）。在我们的研究中，当RNFL偏差图中存在局部缺陷，且该缺陷不像楔形缺陷，同时RNFL厚度图上的RNFL外观呈对称分割时，一束被定义为“分裂”。分类由两名独立观察者进行，他们使用同一组参考示例来标准化分类。
所有病例均达成了观察者间的共识。19例（5.29%）出现双侧上部分裂束，15例（4.16%）观察到单侧上部分裂。325例（90.52%）未发现分裂束。
与单神经纤维层束不同，分裂神经纤维层束在健康眼睛中并非常见表现。在视神经盘外观正常的眼睛中，尤其是当在RNFL偏差图中观察到上部分RNFL缺陷时，还应检查RNLF厚度图和图表以查找分裂神经纤维层束。
