A new way to assess superficial changes to lymphoedema

Background: Appropriate management of lymphoedema requires an accurate diagnosis of the changes in fibrotic induration in order to target treatment. Tonometry is used to measure tissue's resistanceto compression and provide an objective assessment of the stage of lymphoedema, tissue changes and treatment efficacy. The mechanical tonometer that is commonly used has some shortcomings, as the display is difficult to read and has to be read while in place on the limb. A new tool, the indurometer, has been designed to replicate the function of the tonometer, but overcome its shortcomings. Aims: Thisstudy compared a prototype indurometer with the original mechanical tonometer. Methods: A prototype indurometer and an original tonometer were used to measure fibrotic induration levels on 22 subjects with secondary arm lymphoedema taken at six points on each patient's body. The results were analysed for repeatability using a coefficient of variation and the usability of each device was considered. Results: The results from the indurometer had a similar repeatability to the tonometer. The tonometer had consistent repeatability at all measurement sites and, while similarly good, the indurometer's repeatability deteriorated for measurements at the anterior chest. Conclusion: Some changes will need tobe made to the indurometer's design to make measurements more repeatable. Declaration of interest: Olivia Pallotta and Mark McEwen are employed by Flinders Biomedical Enterprises Pty Ltd.