Corneal Stress Distribution Evolves from Thickness-Driven in Normal Corneas to Curvature-Driven with Progression in Keratoconus.
Corneal Stress Distribution Evolves from Thickness-Driven in Normal Corneas to Curvature-Driven with Progression in Keratoconus.
复制标题
DOI：
10.1016/j.xops.2023.100373
复制
发表时间：
2024-03
影响因子：
--
通讯作者：
Yuhas PT
中科院分区：
文献类型：
--
作者：
Roberts CJ;Knoll KM;Mahmoud AM;Hendershot AJ;Yuhas PT
引入新的角膜应力贡献参数(CCS)，比较圆锥角膜(KCN)和正常角膜的应力分布规律。前瞻性、观察性、横断面研究。研究对象包括40名KCN患者的66只眼和155名正常对照(NRL)患者的155只左眼。层析成像计算新提出的CCS，根据无眼内压的环状应力公式R/2t，其中R是曲率半径，t是厚度。根据角膜厚度图和切线曲率图计算CCS图。定制软件确定了最大曲率(Cpot-max)、最薄厚度(Pach-min)、最大应力(CCSmax)和最低应力(CCSmin)的2 mm直径区域。应力差(CCSdiff)计算为CCSmax-CCSmin。计算了Cpot-max与Pach-min、CCSmax与CCSmin以及Pach-min与CCSmax、CCSmin之间的距离。队列间进行t检验，队列内进行配对t检验。参数与距离之间进行一元线性回归分析。显着性阈值为P<；0.05。角膜应力参数、最大曲率、最小厚度的角膜特征，以及角膜应力参数与角膜特征之间的距离。在NRL，P<；0.0001中，CCSmax与Pach-min(0.79±0.92)和Cpot-max(2.04±0.85)比CCSmin(3.17±0.38，2.73±1.53)更接近；而在Kcn，P<；0.0001中，CCSmin与Cpot-max(1.35±1.43)比CCSmax(2.52±0.72)更接近Cpot-max。KCN的Cpot-max(严重程度)与CCSdiff显著相关(P<；0.0001；R2=0.5882)，而NRL的相关性较弱(P<；0.0080，R2=0.0451)。CSPOT-max与PACH-min至CCSmax的距离显著相关(P<；0.0001；R2=0.3737)，而在NRL中无显著意义(P=0.8011)。角膜应力是由NRL的厚度驱动的，在最薄的厚度和最大的曲率处应力最大。然而，随着Kcn的增加，最大应力远离最薄的厚度，而最小应力与最大曲率相关。KCN的严重程度与最大应力和最小应力之间的较大差异显著相关，这与失代偿的生物力学循环一致。专有或商业披露可在本文末尾的脚注和披露中找到。
To introduce the novel parameter of Corneal Contribution to Stress (CCS) and compare stress distribution patterns between keratoconus (KCN) and normal corneas. Prospective, observational, cross-sectional study. The study included 66 eyes of 40 subjects diagnosed with KCN and 155 left eyes from 155 normal control (NRL) subjects. Tomography was obtained to calculate the newly proposed CCS, defined according to the hoop stress formula without intraocular pressure, R/2t, where R is the radius of curvature and t is the thickness. CCS maps were calculated from pachymetry and tangential curvature maps. Custom software identified the 2-mm-diameter zones of greatest curvature (Cspot-max), thinnest pachymetry (Pach-min), greatest stress (CCSmax), and lowest stress (CCSmin). Stress difference (CCSdiff) was calculated as CCSmax – CCSmin. Distances between Cspot-max vs. Pach-min, vs. CCSmax, and vs. CCSmin, as well as between Pach-min vs. CCSmax and vs. CCSmin, were calculated. t tests were performed between cohorts, and paired t tests were performed within cohorts. Univariate linear regression analyses were performed between parameters and distances. The significance threshold was P < 0.05. Corneal stress parameters, corneal features of maximum curvature, minimum thickness, and distances between corneal stress parameters and corneal features. CCSmax was significantly closer to Pach-min (0.79 ± 0.92) and Cspot-max (2.04 ± 0.85) than CCSmin (3.17 ± 0.38, 2.73 ± 1.53, respectively) in NRL, P < 0.0001, whereas CCSmin was significantly closer to Cspot-max (1.35 ± 1.43) than CCSmax (2.52 ± 0.72) in KCN, P < 0.0001. Cspot-max (severity) was significantly related to CCSdiff in KCN (P < 0.0001; R2 = 0.5882) with a weak relationship in NRL (P < 0.0080, R2 = 0.0451). Cspot-max was significantly related to the distance from Pach-min to CCSmax (P < 0.0001; R2 = 0.3737) without significance in NRL (P = 0.8011). Corneal stress is driven by thickness in NRL, with greatest stress at thinnest pachymetry and greatest curvature. However, maximum stress moves away from thinnest pachymetry with progression in KCN, and minimum stress is associated with maximum curvature. Severity in KCN is significantly related to greater difference between maximum and minimum stress, consistent with the biomechanical cycle of decompensation. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
登录
查看更多内容
影响因子：
3.7
作者：
Li J;Ji P;Lin X
通讯作者：
Lin X
影响因子：
2.8
作者：
Roberts CJ;Dupps WJ Jr
通讯作者：
Dupps WJ Jr
影响因子：
2.8
作者：
Labiris, Georgios;Giarmoukakis, Athanassios;Seitz, Berthold
通讯作者：
Seitz, Berthold
影响因子：
8.1
作者：
Scarcelli G;Besner S;Pineda R;Kalout P;Yun SH
通讯作者：
Yun SH
DOI：
10.1016/j.jmbbm.2008.07.002
发表时间：
2009-07-01
影响因子：
3.9
作者：
Gefen, Amit;Shalom, Ran;Mandel, Yossi
通讯作者：
Mandel, Yossi