Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Ophthalmology, Seoul National University Hospital, Seoul, Republic of Korea.
Department of Biomedical Engineering, National University of Singapore, Singapore, Republic of Singapore; Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore.
Ophthalmology. 2018 Dec;125(12):1898-1906. doi: 10.1016/j.ophtha.2018.05.017. Epub 2018 Jun 23.
To investigate the relationship between the degree of posterior bowing of the lamina cribrosa (LC) at baseline and the rate of subsequent visual field (VF) progression in eyes with primary open-angle glaucoma (POAG).
Prospective, observational study.
One hundred one early-stage (VF mean deviation [MD], -5.0 to -0.01 dB) POAG eyes that met the following conditions: (1) follow-up longer than 3.5 years, (2) more than 5 reliable standard automated perimetry tests, and (3) medically well-controlled intraocular pressure during follow-up.
All participants underwent swept-source OCT scanning of the LC at baseline. The area enclosed by a vertical line at the anterior laminar insertion, anterior LC plane, and reference plane of Bruch's membrane opening (BMO) was divided by D (distance between the 2 cross-points made by vertical lines drawn from the anterior laminar insertion to the reference plane of BMO) to approximate the LC depth (LCD). The difference between the LCD and mean anterior laminar insertion depth was defined as the LC curvature index (LCCI). To consider the steepness of the LC curve, the adjusted LCCI (aLCCI) was calculated as LCCI divided by D and multiplied by 100. The mean LCD (mLCD), mean LCCI (mLCCI), and mean aLCCI (maLCCI) were computed by averaging the measurements on 12 radial scans. The subsequent MD slope and associated factors were analyzed.
Lamina cribrosa parameters and subsequent MD slope.
The participants' mean baseline MD was -3.8 ± 3.4 dB. The mean baseline mLCD, mLCCI, and maLCCI were 419.0 ± 111.2 μm, 76.4 ± 29.0 μm, and 4.8 ± 1.9, respectively. A greater MD slope was associated with a greater baseline maLCCI (P < 0.001). We found a statistically significant breakpoint for the maLCCI (4.12) above which a larger maLCCI showed a steeper MD slope (P < 0.001). Analysis by age revealed that significantly more VF progression with maLCCI changes occurred in the relatively younger group (≤69 years; P = 0.043).
The baseline maLCCI showed a significant correlation with the rate of subsequent VF deterioration. This suggests that, in POAG eyes with greater posterior bowing of the LC, the axons of retinal ganglion cells may be more vulnerable to further glaucomatous injury.
探讨原发性开角型青光眼（POAG）患者视盘筛板后区（LC）后凸程度与后续视野（VF）进展率之间的关系。
前瞻性、观察性研究。
101 例早期（VF 平均偏差[MD]，-5.0 至-0.01 dB）POAG 眼，符合以下条件：（1）随访时间超过 3.5 年，（2）超过 5 次可靠的标准自动视野检查，（3）随访期间眼内压得到良好的医学控制。
所有参与者均在基线时接受 LC 的扫频源 OCT 扫描。从前层插入处的垂直线、前 LC 平面和 Bruch 膜开口（BMO）的参考平面所围成的区域除以 D（从前层插入处画的两条垂直线到 BMO 参考平面的交点之间的距离），以近似 LC 深度（LCD）。LCD 与平均前层插入深度之间的差值定义为 LC 曲率指数（LCCI）。为了考虑 LC 曲线的陡峭程度，计算校正后的 LCCI（aLCCI），方法是将 LCCI 除以 D，然后乘以 100。通过对 12 条放射状扫描的测量值进行平均，计算出平均 LCD（mLCD）、平均 LCCI（mLCCI）和平均 aLCCI（maLCCI）。分析后续 MD 斜率及其相关因素。
LC 筛板参数和后续 MD 斜率。
参与者的平均基线 MD 为-3.8 ± 3.4 dB。平均基线 mLCD、mLCCI 和 maLCCI 分别为 419.0 ± 111.2 μm、76.4 ± 29.0 μm 和 4.8 ± 1.9。较大的 MD 斜率与较大的基线 maLCCI 相关（P < 0.001）。我们发现 maLCCI 有一个统计学上的显著断点（4.12），超过该点，maLCCI 越大，MD 斜率越陡（P < 0.001）。通过年龄分析发现，在相对较年轻的组（≤69 岁；P = 0.043）中，maLCCI 变化导致的 VF 进展更为显著。
基线 maLCCI 与后续 VF 恶化率有显著相关性。这表明，在 LC 后凸程度较大的 POAG 眼中，视网膜神经节细胞的轴突可能更容易受到进一步的青光眼损伤。
