Abstract
Purpose :
Although near-work and outdoor exposure have been generally accepted as myopia-related behaviors, with the former as a risk and the latter a protective factor, results regarding the quantitative correlation between them are inconsistent. One of the major reasons is that conventional approaches (eg., questionnaire and diary) could only provide an overall period-based data (eg., at most daily), which are not without memory bias. The purpose of the study was to test the capability of a newly developed wearable device to record the myopia-related behavior.
Methods :
A wearable device (Clouclip™) with 46×13 ×8.5 mm in size and 6 g in weight was developed, which is attached in the spectacle for use. Within the device, an infrared sensor was utilized to measure reading distance; an integrated chip to measure ambient illuminance; an ultraviolet sensor to distinguish the indoor or outdoor environment; and an angular acceleration sensor (X, Y, Z axis) to detect the status of wearing or not wearing. The sampling frequency of Clouclip™ is 1 Hz. Data in Clouclip™ is transmitted via Bluetooth to the APP in a smartphone and then stored in the cloud for future analysis. Nine different distances (ranged from 18cm to 55cm) and four levels of illuminances (ranged from 100 lux to 2000 lux) were set in the lab to validate the accuracy of measurement by Clouclip™. Paired-t test and student’s correlation were utilized to compare between the actual values and the measured ones by Clouclip™. Significant level was set at p <0.05.
Results :
The difference between the measured and the actual distance was -0.78 +/- 0.83 mm, which was significantly correlated (r=1.0, p<0.001). Likewise, the difference between the measured and the actual illuminance was -54.25 +/- 37.62 lux, which was significantly correlated(r=1.0, p<0.001). The correct detection rate of indoor/outdoor environment and the status of wearing or not wearing are both 100%.
Conclusions :
The study in the lab shows that Clouclip™ provides real-time and accurate measurement about the mentioned environmental factors. It appears that Clouclip™ offers a promising approach to investigate the correlation between myopia development and these factors. However, field studies are warranted for further validation.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.