Kozobolis Vassilios P, Paschalis Eleftherios I, Foudoulakis Nikitas C, Koukoula Stavrenia C, Labiris Georgios
Department of Ophthalmology and Eye Institute of Thrace, Democritus University of Thrace, Alexandroupolis, Greece.
Clin Ophthalmol. 2010 Sep 7;4:937-45. doi: 10.2147/opth.s11967.
To develop, characterize, and validate a prototype digital aqueous humor outflow tonographer (DAHOM).
The DAHOM was developed, characterized, and validated in three phases. Phase 1 involved construction of the sensor. This was broadly based on the fundamental design of a typical Schiotz tonographer with a series of improvements, including corneal indentation, which was converted to an electrical signal via a linear variable differential transducer, an analog signal which was converted to digital via ADC circuitry, and digital data acquisition and processing which was made possible by a serial port interface. Phase 2 comprised development of software for automated assessment of the outflow facility. Automated outflow facility assessment incorporated a series of fundamental improvements in comparison with traditional techniques, including software-based filtering of ripple noise and extreme variations, rigidity impact analysis, and evaluation of the impact of patient age, central corneal thickness, and ocular axial length. Phase 3 comprised characterization and validation of DAHOM, for which we developed an experimental setup using porcine cadaver eyes. DAHOM's repeatability was evaluated by means of Cronbach's alpha and intraclass correlation coefficient. The level of agreement with a standard Schiotz tonographer was evaluated by means of paired t-tests and Bland-Altman analysis in human eyes.
The experimental setup provided the necessary data for the characterization of DAHOM. A fourth order polynomial equation provided excellent fit (R square >0.999). DAHOM demonstrated high repeatability (Cronbach's alpha ≥0.997; intraclass correlation coefficient ≥0.987) and an adequate level of agreement with a standard Schiotz tonographer.
This study presents the development, characterization, and validation of a prototype digital tonographer. DAHOM demonstrates high repeatability and a sufficient level of agreement with a typical Schiotz tonographer, while its digital design remedies known vulnerabilities of conventional tonographers.
研发、表征并验证一款数字房水流出眼压计（DAHOM）原型。
DAHOM的研发、表征及验证分三个阶段进行。第一阶段涉及传感器的构建。其大致基于典型的席氏眼压计的基本设计，并进行了一系列改进，包括角膜压痕，通过线性可变差动传感器将其转换为电信号，经模数转换电路将模拟信号转换为数字信号，并通过串行端口接口实现数字数据采集与处理。第二阶段包括用于自动评估流出功能的软件的开发。与传统技术相比，自动流出功能评估进行了一系列根本性改进，包括基于软件的波纹噪声和极端变化滤波、刚性影响分析以及对患者年龄、中央角膜厚度和眼轴长度影响的评估。第三阶段包括DAHOM的表征与验证，为此我们使用猪尸体眼开发了一个实验装置。通过克朗巴赫α系数和组内相关系数评估DAHOM的重复性。在人眼中，通过配对t检验和布兰德 - 奥特曼分析评估与标准席氏眼压计的一致性水平。
实验装置为DAHOM的表征提供了必要数据。一个四阶多项式方程拟合效果极佳（决定系数R²>0.999）。DAHOM具有高重复性（克朗巴赫α系数≥0.997；组内相关系数≥0.987），并且与标准席氏眼压计的一致性水平良好。
本研究展示了一款数字眼压计原型的研发、表征及验证。DAHOM具有高重复性，与典型的席氏眼压计一致性水平良好，同时其数字设计弥补了传统眼压计已知的弱点。
