Objective Monitoring of Spectacle Wearing Times in Adult Subjects Using the Theramon^® Thermosensor

Abstract

Purpose

To find a reliable method to determine the wearing times of glasses in adults objectively on the basis of temperature measurements of the small-sized theramon^® thermosensor device (TM) from orthodontics. Furthermore, the reliability of the determined wearing times during well and poor position of spectacles was explored. To address the previously reported lack of accuracy during higher outside temperatures, this study was conducted in midsummer and autumn.

Patients and Methods

Twenty adults wore their spectacles with three TMs attached to both inner sides and the right outer side in a period of three consecutive days. They were asked to report wearing and non-wearing times, indoor and outdoor activities and subjective perception of spectacle position as accurately as possible. To find the most reliable way to determine spectacle wearing times compared to protocolled wearing times, we applied and evaluated temperature categorizing methods and visual analysis of time logged temperatures. Percent error and percent accuracy of each method were calculated. The methods mentioned were applied and evaluated to determine poor spectacle position.

Results

Median percent errors of the most reliable determination methods were <10% with an accuracy between 90% and 96%. Comparing the most reliable methods, determinations on the basis of midsummer measurements (median percent error 0% to 2%, median percent accuracy 96%) were more accurate than on the basis of autumn measurements (median percent error −5% to −20%, median percent accuracy 90%). Poor spectacle position could be determined with a median percent error of 0% and a median percent accuracy of 100% by analysing the temperature measurements of TM’s visually.

Conclusion

A reliable and objective determination of spectacle wearing times is possible on the basis of TM temperature measurements in a standard clinical setting. Measurements of one inner TM seem to be sufficient to determine the wearing times and are more appealing. Poor spectacle position can be determined reliably by analysing visually the time logged temperatures. The findings of this study require further studies on larger groups of affected, amblyopic patients and children, to analyse the real impact of spectacle wearing times and poor spectacle position on visual development.

Keywords:

• amblyopia
• spectacle wearing times
• objective monitoring
• theramon^® thermosensor
• spectacle adherence

Abbreviations

TM, theramon^® thermosensor; SD, standard deviation.

Data-Sharing Statement

All data mentioned in the study are available and can be supplied upon request from the corresponding author.

Ethics Approval

All procedures performed in the study were in accordance with the ethical standards of the Institutional Review Board and ethical committee of Eberhard-Karls-University Tübingen and with the 1964 Declaration of Helsinki and its later amendments.

Informed Consent

Informed consent to participate and for publication was obtained from all participants included in the study. The person in Figure 1 has provided informed consent for the image to be published.

Disclosure

The authors declare that they have no conflicts of interest for this work.

Additional information

Funding

No funding was received throughout the study.