Jung Younhea, Park Hae-Young L, Oh Sieun, Park Chan Kee
Department of Ophthalmology, Yeouido St. Mary's Hospital, College of Medicine.
Department of Ophthalmology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Medicine (Baltimore). 2020 Feb;99(7):e19126. doi: 10.1097/MD.0000000000019126.
Structural differences have been reported between primary open angle glaucoma (POAG) and normal tension glaucoma (NTG), and biomechanical differences between POAG and NTG may account for why NTG patients are more vulnerable to lower intraocular pressure (IOP). This study compared the biomechanical properties of POAG and NTG patients using the Corvis scheimpflug technology (ST) non-contact Scheimpflug-based tonometer, and determined the factors associated with these properties.In this retrospective cross-sectional study, 46 eyes with POAG, 54 eyes with NTG, and 61 control eyes were included. A non-contact Scheimpflug-based tonometer was used to examine and compare the corneal biomechanical responses in the POAG, NTG, and normal groups. We used univariate and multivariate regression analyses to determine the factors associated with the deformation amplitude in each group.Baseline characteristics, including age, IOP, spherical equivalent, keratometry, axial length, and central corneal thickness, were similar among the 3 groups. Severity of glaucoma, as measured by mean deviation, was similar between POAG and NTG groups. Applanation 1 velocity and deformation amplitude were significantly smaller in POAG (0.13 ± 0.02 and 1.06 ± 0.14, respectively) than NTG (0.14 ± 0.01 and 1.13 ± 0.11, respectively) and normal groups (0.14 ± 0.02 and 1.13 ± 0.10, respectively). Radius of curvature was significantly larger in the POAG group compared to the normal group. In normal controls, IOP and keratometry were significant factors related to deformation amplitude. In POAG eyes, IOP was a statistically significant predictor of deformation amplitude. In NTG eyes, however, IOP , keratometry, and axial length were statistically significant predictors of deformation amplitude.POAG eyes showed less deformable corneas compared to NTG and normal controls. IOP was significantly correlated with deformation amplitude in all groups. However, axial length was positively correlated with deformation amplitude only in NTG eyes. Characterization of the differences in biomechanical properties between POAG and NTG may contribute to a better understanding of the underlying pathophysiologies associated with these diseases.
已有报道称原发性开角型青光眼（POAG）与正常眼压性青光眼（NTG）之间存在结构差异，POAG与NTG之间的生物力学差异可能解释了为什么NTG患者更容易受到较低眼压（IOP）的影响。本研究使用Corvis Scheimpflug技术（ST）非接触式基于Scheimpflug原理的眼压计比较了POAG和NTG患者的生物力学特性，并确定了与这些特性相关的因素。
在这项回顾性横断面研究中，纳入了46只POAG眼、54只NTG眼和61只对照眼。使用非接触式基于Scheimpflug原理的眼压计检查并比较POAG组、NTG组和正常组的角膜生物力学反应。我们使用单变量和多变量回归分析来确定每组中与变形幅度相关的因素。
3组之间的基线特征，包括年龄、眼压、等效球镜度、角膜曲率、眼轴长度和中央角膜厚度相似。通过平均偏差测量的青光眼严重程度在POAG组和NTG组之间相似。POAG组的压平1速度和变形幅度（分别为0.13±0.02和1.06±0.14）显著小于NTG组（分别为0.14±0.01和1.13±0.11）和正常组（分别为0.14±0.02和1.13±0.10）。与正常组相比，POAG组的曲率半径显著更大。在正常对照组中，眼压和角膜曲率是与变形幅度相关的显著因素。在POAG眼中，眼压是变形幅度的统计学显著预测因子。然而，在NTG眼中，眼压、角膜曲率和眼轴长度是变形幅度的统计学显著预测因子。
与NTG和正常对照组相比，POAG眼的角膜变形性较小。眼压在所有组中均与变形幅度显著相关。然而，仅在NTG眼中眼轴长度与变形幅度呈正相关。POAG和NTG之间生物力学特性差异的表征可能有助于更好地理解与这些疾病相关的潜在病理生理学。
