Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
School of Meidicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC.
J Chin Med Assoc. 2021 Mar 1;84(3):320-325. doi: 10.1097/JCMA.0000000000000476.
To compare the utility of the iCare, Tono-Pen, and non-contact airpuff (NCT) tonometers with the Goldmann applanation tonometer (GAT) for measuring intraocular pressure (IOP) in patients with corneal edema after penetrating keratoplasty (PKP) and to assess the effects of central corneal thickness (CCT) and corneal curvature (CC) on IOP measurements.
Thirty-two eyes of 27 patients with corneal edema after PKP due to corneal abnormalities and 43 control eyes of 30 patients with normal corneas were recruited. Before IOP measurements, all patients underwent a baseline examination, including auto-refraction, keratometry, slit lamp biomicroscopy, and CCT measurement. IOP was measured using the devices in the same order: first the NCT, followed by the iCare, Tono-Pen, and GAT. The differences between the iCare, Tono-Pen, NCT, and GAT were calculated with repeated-measures analysis of variance. The Bland-Altman method was used to assess the agreement between the iCare, Tono-Pen, and NCT versus the GAT. The influences of CCT and CC on IOP measurement were evaluated by correlation analysis using Pearson's correlation coefficient.
Mean IOP measurements were significantly higher with the NCT and Tono-Pen than with the GAT in the PKP and control groups. When compared with GAT, iCare showed significantly higher IOP readings in the control group, but the IOP readings did not differ between the iCare and GAT in the PKP group. Poor agreement was noted between the NCT and GAT in both groups. The Tono-Pen showed clinically acceptable agreement with GAT in control eyes and poor agreement in PKP eyes. The agreement between the iCare and GAT appeared to be clinically acceptable in both groups. Correlation analysis of the results from control eyes showed that the IOP measurements with the GAT and NCT were weakly related to CCT and moderately correlated with CC. The iCare IOP readings were weakly correlated with CCT and CC.
In the PKP group, the NCT and Tono-Pen significantly overestimated IOP, whereas the iCare IOP readings were similar to those obtained using the GAT. Poor agreement was noted between the NCT and GAT as well as between the Tono-Pen and GAT, but the iCare showed clinically acceptable agreement with GAT. In normal corneas, the GAT, NCT, and iCare were affected by CCT and CC. The iCare tonometer was less affected by corneal edema than were the NCT and the Tono-Pen. The iCare appears to be a useful device for IOP measurement in eyes with corneal edema after PKP.
比较 iCare、Tono-Pen 和非接触空气脉冲（NCT）眼压计与 Goldmann 压平眼压计（GAT）在穿透性角膜移植（PKP）后角膜水肿患者中测量眼内压（IOP）的效用，并评估中央角膜厚度（CCT）和角膜曲率（CC）对 IOP 测量的影响。
招募了 32 只因角膜异常而接受 PKP 后角膜水肿的 27 例患者的 32 只眼，以及 30 例正常角膜的 43 只对照眼。在进行 IOP 测量之前，所有患者均进行了基线检查，包括自动折射、角膜曲率、裂隙灯生物显微镜和 CCT 测量。IOP 依次使用以下设备进行测量：首先是 NCT，然后是 iCare、Tono-Pen 和 GAT。使用重复测量方差分析计算 iCare、Tono-Pen、NCT 和 GAT 之间的差异。使用 Bland-Altman 方法评估 iCare、Tono-Pen 和 NCT 与 GAT 之间的一致性。使用 Pearson 相关系数评估 CCT 和 CC 对 IOP 测量的影响。
在 PKP 和对照组中，NCT 和 Tono-Pen 测量的平均 IOP 明显高于 GAT。与 GAT 相比，iCare 在对照组中显示出明显更高的 IOP 读数，但在 PKP 组中，iCare 和 GAT 之间的 IOP 读数没有差异。两组中 NCT 与 GAT 之间的一致性较差。Tono-Pen 在对照组中与 GAT 具有临床可接受的一致性，而在 PKP 组中则一致性较差。iCare 与 GAT 之间的一致性在两组中似乎具有临床可接受性。对对照组的结果进行相关性分析显示，GAT 和 NCT 的 IOP 测量值与 CCT 呈弱相关，与 CC 呈中度相关。iCare 的 IOP 读数与 CCT 和 CC 呈弱相关。
在 PKP 组中，NCT 和 Tono-Pen 明显高估了 IOP，而 iCare 的 IOP 读数与 GAT 相似。NCT 与 GAT 以及 Tono-Pen 与 GAT 之间的一致性较差，但 iCare 与 GAT 具有临床可接受的一致性。在正常角膜中，GAT、NCT 和 iCare 受 CCT 和 CC 的影响。iCare 受角膜水肿的影响小于 NCT 和 Tono-Pen。iCare 似乎是 PKP 后角膜水肿患者测量 IOP 的有用工具。
