Purpose

To investigate the positional change of central retinal vasculature and vascular trunk to deduce the change in the lamina cribrosa (LC) during axial elongation.

Design

Prospective cohort study.

Participants

Twenty-three healthy myopic children (46 eyes).

Methods

Participants had undergone a full ophthalmologic examination and axial length measurement every 6 months for 2 years. Using spectral-domain OCT, circle scans centered around the optic disc in the glaucoma progression analysis mode, which enabled capturing of the same positions throughout the entire study period, and enhanced depth imaging of the deep optic nerve head complex were performed. Infrared imaging of the circle scans was used to measure the changes in the angles between the first and final visits. The angle between the major superior and inferior retinal arteries was measured along the circle scan twice: from the center of the circle scan and from the central retinal vascular trunk, respectively. The positional change of the retinal vascular trunk also was measured.

Main Outcome Measures

Change in vascular angle and position of vascular trunk with axial elongation and associated factors.

Results

The vascular angle measured from the center of the circle scan did not change (P = 0.247), whereas the angle measured from the central retinal arterial trunk decreased with axial elongation (P < 0.001). A generalized estimating equation analysis revealed that the factors associated with angle decrease were axial elongation (P = 0.004) and vascular trunk dragging (P < 0.001). The extent of vascular trunk dragging was associated with axial elongation (P < 0.001) and increased border length with marginal significance (P = 0.053), but the extent of dragging could not be explained fully by their combination. The major directionality of dragging was mostly to the nasal side of the optic disc, with large variations among participants.

Conclusions

During axial elongation, the retinal vasculature at the posterior pole was unchanged, whereas the position of the central vascular trunk was dragged nasally. Because the central retinal vascular trunk is embedded in the LC, its dragging indicates nasal shifting of the LC, which could explain the vulnerability of myopic eyes to glaucomatous optic neuropathy.

中文翻译：

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轴突伸长时视神经头脉管的位置变化，以板状薄板移位为证据

目的

目的研究视网膜中央血管和血管干的位置变化，以推断轴向延伸过程中筛板（LC）的变化。

设计

前瞻性队列研究。

参加者

23名健康的近视儿童（46眼）。

方法

参与者每6个月接受一次全面的眼科检查和轴长测量，为期2年。使用光谱域OCT，在青光眼进展分析模式下以视盘为中心进行圆形扫描，从而可以在整个研究期间捕获相同的位置，并增强了深视神经头复合体的深度成像。圆扫描的红外成像用于测量第一次和最后一次就诊之间的角度变化。沿圆形扫描两次测量视网膜上，下视网膜主要动脉之间的角度：分别从圆形扫描的中心和视网膜中央血管主干开始。还测量了视网膜血管主干的位置变化。

主要观察指标

血管角度和血管干的位置随轴向伸长率及相关因素的变化。

结果

从圆形扫描中心测得的血管角度没有变化（P  = 0.247），而从视网膜中央动脉干测得的角度随着轴向伸长而减小（P <0.001）。广义估计方程分析表明，与角度减小相关的因素是轴向伸长（P  = 0.004）和血管干阻力（P <0.001）。血管主干的牵拉程度与轴向伸长率相关（P <0.001）和边界长度的增加具有边际意义（P = 0.053），但无法通过其组合完全解释拖动的程度。拖动的主要方向主要是向视盘的鼻侧移动，参与者之间的差异很大。

结论

在轴向伸长过程中，后极处的视网膜脉管系统未变，而中央血管干的位置被鼻部拖拉。由于视网膜中央血管主干埋在LC中，其拖曳表明LC发生了鼻部移位，这可以解释近视眼对青光眼性视神经病变的脆弱性。