Quantifying Head Position Following Vitrectomy Using a 3-Dimensional Position Sensor Embedded in a Novel Ophthalmic Shield: A Pilot Study

Abstract

Purpose: To assess head position after pars plana vitrectomy using a novel low-energy, nonintrusive three-dimensional position sensor platform.Methods: In this prospective nonrandomized interventional case series, a low-energy Bluetooth smart sensor housed within a novel eye shield recorded three-dimensional positional data every 5 minutes. The device was placed on the patient immediately after pars plana vitrectomy, and data were retrieved at the postoperative Day 1 visit. Readings were processed by vector analysis into four groups, stratified by the angle of deviation away from a completely prone head position. The primary outcome was the angle between vectors.Results: Ten patients were enrolled in this pilot study. The mean (SD) age was 57.5 (17.4). A total of 2,318 readings with a mean (SD) of 231.8 (26.8) readings per patient were obtained. The mean (SD) number of readings were 132.9 (34.7) while awake and 98.9 (27.9) during sleep. Of total readings, only 11.7% fell into Group 1, whereas a majority of readings fell in Group 2 (52.4%) and Group 3 (32.4%), and only 3.5% fell into Group 4. Positional deviation increased during sleep hours, with about 46.8% of readings at a reclined angle (Group 3) and 4.9% supine, which was 21.6% and 2.5%, respectively, during the wake time (P , 0.001, P = 0.002, respectively).Conclusion: In this pilot study, a nonintrusive wireless three-dimensional position sensor-shield platform was tolerated well and capable of capturing positional data. Adherence to face-down positioning was low, and positional deviation increased significantly while sleeping.