Purpose

To study the correlation between corneal and scleral intraocular pressure (IOP) by pneumatonometry in pediatric patients.

Design

Cross-sectional study.

Participants

Patients (age range, 0–15 years) undergoing an eye examination under anesthesia or eye surgery were recruited at the University of California, San Francisco, Benioff Children's Hospital between July 2015 and April 2016.

Methods

Intraocular pressure measurements were obtained by pneumatonometry on the central cornea and the inferonasal and inferotemporal sclera in a random order. Spearman correlations between corneal versus inferonasal scleral IOP and corneal versus inferotemporal scleral IOP were calculated. A linear mixed-effect model was used to derive a predictive equation for corneal IOP from scleral IOP and to perform covariate analysis for age, axial length, central corneal thickness, and lens status. The standard deviation of the predicted corneal IOP was determined by bootstrap mixed-effect regression analysis.

Main Outcome Measures

The predictive model of corneal IOP from scleral IOP.

Results

Seventy-five eyes from 40 patients were included in the study. Spearman correlation coefficient for corneal versus inferotemporal scleral IOP was 0.79 (P < 0.01) and 0.48 for corneal versus inferonasal scleral IOP (P < 0.01). Corneal IOP may be predicted from scleral IOP via the following equations: corneal IOP = 0.73 × inferotemporal scleral IOP + 7.45 and corneal IOP = 0.21 × inferonasal scleral IOP + 17.83. Central corneal thickness (P = 0.07), lens status (P = 0.4), age (P = 0.33), and axial length (P = 0.15) did not affect significantly the relationship between corneal and scleral IOP in the multivariate regression analysis. The standard deviation of predicted corneal IOP was less than 1.2 mmHg within an inferotemporal scleral IOP range of 10 to 35 mmHg.

Conclusions

In children, corneal and scleral IOP are correlated significantly when measured by pneumatonometry. Measurements obtained from the inferotemporal sclera are better predictors of corneal IOP than those obtained from inferonasal sclera. Pneumatonometry on the inferotemporal sclera may be an alternative method to estimate IOP for pediatric patients from whom corneal IOP measurement is difficult to obtain.

中文翻译：

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儿科患者角膜和巩膜肺通气量测定法的相关性

目的

通过肺气量法研究儿科患者的角膜和巩膜眼压（IOP）之间的相关性。

设计

横断面研究。

参加者

在2015年7月至2016年4月期间，从加利福尼亚大学旧金山分校贝尼奥夫儿童医院招募了接受麻醉或眼科手术进行眼科检查的患者（年龄范围为0至15岁）。

方法

眼压测量是通过肺气量计法以随机顺序在中央角膜以及鼻下和颞下巩膜获得的。计算角膜与鼻下巩膜IOP和角膜与颞下巩膜IOP之间的Spearman相关性。使用线性混合效应模型从巩膜IOP得出角膜IOP的预测方程，并对年龄，轴向长度，中央角膜厚度和晶状体状态进行协变量分析。通过自举混合效应回归分析确定预测的角膜IOP的标准差。

主要观察指标

从巩膜眼压预测角膜眼压的模型。

结果

来自40名患者的75只眼睛被包括在研究中。角膜与颞下巩膜IOP的Spearman相关系数为0.79（P <0.01），而角膜与鼻下巩膜IOP的Spearman相关系数为0.48（P  <0.01）。可通过以下等式从巩膜IOP预测角膜IOP：角膜IOP = 0.73×颞下巩膜IOP + 7.45和角膜IOP = 0.21×鼻下巩膜IOP + 17.83。中央角膜厚度（P  = 0.07），晶状体状态（P  = 0.4），年龄（P  = 0.33）和轴向长度（P = 0.15）在多元回归分析中对角膜和巩膜IOP之间的关系没有显着影响。在10到35 mmHg的颞下巩膜IOP范围内，预测的角膜IOP的标准偏差小于1.2 mmHg。

结论

对于儿童，通过肺动脉压法进行测量时，角膜和巩膜的眼压显着相关。从颞下巩膜获得的测量值比从鼻下巩膜获得的测量值更好地预测角膜IOP。颞下巩膜的肺动脉压测定法可能是一种难以估计角膜眼压的儿科患者眼压的替代方法。