Objective Assessment of Spectacle Wear in Infants and Toddlers Using a Wearable Sensor

PURPOSE: To assess the feasibility of using a thermal microsensor to monitor spectacle wear in infants and toddlers, to determine the inter-method reliability of two methods of estimating spectacle wear from sensor data, and to validate sensor estimates of wear. METHODS: Fourteen children, 3 to <48 months of age, and one adult were provided pediatric spectacles containing their spectacle prescription. A thermal microsensor attached to the spectacle headband recorded date, time, and ambient temperature every 15 minutes for 14 days. Parents were asked for daily spectacle wear reports, and the adult recorded wear using a smartphone app. Sensor data were dichotomized (wear/non-wear) using two methods: temperature threshold (TT) and human judgment (HJ). Kappa statistics assessed inter-method reliability (child data) and accuracy (adult data). RESULTS: Data from two child participants were excluded (one because of corrupted sensor data and the other because of no parent log data). Sensor data were collected more reliably than parent wear reports. The TT and HJ analysis of child data yielded similar reliability. Adult sensor data scored using the HJ method provided more valid estimates of wear than the TT method (κ = 0.94 vs. 0.78). CONCLUSIONS: We have demonstrated that it is feasible to deduce periods of spectacle wear using a thermal data logger and that the sensor is tolerated by children. TRANSLATIONAL RELEVANCE: Results indicate that it is feasible to use a thermal microsensor to measure spectacle wear for use in clinical monitoring or for research on spectacle treatment in children under 4 years of age.