Wong Yin-zhi, Lam Andrew K C
School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Clin Exp Optom. 2011 Sep;94(5):418-24. doi: 10.1111/j.1444-0938.2011.00591.x. Epub 2011 Mar 24.
This study investigated the influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis (CH) and the corneal resistance factor (CRF) in a group of normal Chinese persons.
Ninety-five participants were recruited and data from the eye with higher corneal astigmatism were analysed. The anterior corneal curvature was measured by corneal topography. The Goldmann-correlated intraocular pressure (IOPg), corneal-compensated intraocular pressure (IOPcc), CH and CRF at different meridians (default horizontal position, 10°, 20° and 30° along the superotemporal and inferonasal meridians) were obtained from an ocular response analyser. The corneal powers at these specific meridians also were calculated.
At the default position, the IOPg and CRF had weak correlations with corneal astigmatism, while the IOPcc and CH were not significantly correlated with corneal astigmatism. Both the IOPg and IOPcc were measured significantly higher at the default position. The CH and CRF were lower at the default position but the difference in the CRF from obliquity could not reach statistical significance. The CH was not significantly correlated with the corneal power at all meridians. The CRF correlated with the corneal power only at 30° superotemporal.
Corneal astigmatism and head tilt did not have much effect on the measurement of CH and the CRF, both of which were lowest along the horizontal meridian. Clinically, the difference was small. The influence of corneal power on CH and the CRF was minimal.
本研究调查了一组正常中国人中角膜散光、角膜曲率和子午线差异对角膜滞后（CH）和角膜阻力因子（CRF）的影响。
招募了95名参与者，并分析了角膜散光较高眼的数据。通过角膜地形图测量前角膜曲率。从眼反应分析仪获得不同子午线（默认水平位置、沿颞上和鼻下子午线10°、20°和30°）的Goldmann相关眼压（IOPg）、角膜补偿眼压（IOPcc）、CH和CRF。还计算了这些特定子午线处的角膜屈光力。
在默认位置，IOPg和CRF与角膜散光呈弱相关，而IOPcc和CH与角膜散光无显著相关性。在默认位置测量的IOPg和IOPcc均显著更高。CH和CRF在默认位置较低，但CRF与倾斜度的差异未达到统计学显著性。CH与所有子午线处的角膜屈光力均无显著相关性。CRF仅在颞上30°处与角膜屈光力相关。
角膜散光和头部倾斜对CH和CRF的测量影响不大，二者在水平子午线上均最低。临床上，差异较小。角膜屈光力对CH和CRF的影响最小。
