Accuracy of a Virtual Maddox Rod Smartphone App for Sensorimotor Examination

Title Accuracy of a Virtual Maddox Rod Smartphone App for Sensorimotor Examination
Author, Co-Author Kevin Houston, Shrinivas Pundlik, Matteo Tomasi, Gang Luo
Topic Binocular Vision/Pediatrics
Year
2016
Day
Thursday
Program Number
165031
Room
Ballroom A-B
Affiliation
Mass Eye and Ear, Harvard Department of Ophthalmology
Abstract

Purpose: A sensorimotor exam measures eye alignment in a miniumum of 4 different gaze directions. The purpose of this study was to develop and evaluate a smartphone app for sensorimotor examination.

Methods: We developed a head-mounted virtual reality (VR) smartphone app to simulate the Maddox Rod test in 4 positions of gaze. Ten adult participants (age < 35) wore the smartphone VR headset and used a Bluetooth remote to align a red line and white dot each visible to only the right and left eyes respectively.  Measurements were performed in horizontal and vertical directions 3 times each in primary gaze, and then at gaze 10° left, right, and down. The sequence was repeated with a 7Δ Fresnel prism base-out and then base-down (counterbalanced) over the right eye to provide a ground-truth by which to calculate accuracy of the app. The difference between prism and no prism conditions (within subjects) was the outcome measure.

Results: The mean absolute error (prism nominal value – app measurement) was (0.9 ± 0.6 Δ) in the vertical measurement and (1.3 ± 0.9Δ) in the horizontal measurement.

Conclusion: The app accurately measures the motor field portion of the sensorimotor exam. 

Affiliation of Co-Authors Schepens Eye Research Institute, Schepens Eye Research Institute, Schepens Eye Research Institute
Outline