Abstract
Purpose :
Detection of strabismus in children during vision screening is crucial in the prevention of amblyopia. Spot, a handheld photoscreening device, refers for strabismus based on its measurement of “gaze”. Thus this study sought to evaluate the ability of the Spot to detect constant strabismus in primary gaze compared to results from a complete eye exam. According to the 2013 guidelines for the detection of amblyogenic risk factors released by the American Association for Pediatric Ophthalmology and Strabismus (AAPOS), strabismus ≥ 8 Δ is considered important to detect by automated vision screening devices.This is a revised recommendation from the 2003 guidelines which recommended referral for any manifest strabismus found during screening.
Methods :
481 children aged 20 to 99 months were screened by a lay screener and then received a comprehensive eye exam (CEE) by a masked pediatric optometrist on a mobile eye clinic van. Screeners were trained to use the Spot by a manufacturer representative. Screening results were then compared to cover test findings to determine the sensitivity and specificity of the Spot v.1.1.51 to detect any constant strabismus and strabismus ≥ 8 Δ.
Results :
Of the 481 children, 10 (2.08%) were determined to have constant strabismus while 8 (1.66 %) had stabismus >/= 8 Δ. The sensitivity of the Spot to detect any strabismus was 10% (0.52, 45.9) and the specificity was 99.4% (98.0, 99.8) and 11% (0.58, 49.33) and 99.4% (98.0, 99.8) respectively for stabismus >/= 8 Δ. Spot correctly identified only one subject with strabismus for "gaze". The Spot entirely missed nine subjects with strabismus, mean = 17 Δ, and referred three for gaze who were determined orthophoric by CEE. The positive likelihood ratio was 16 (1.78, 1.38) and the negative likelihood ratio was 0.91 (0.74, 1.11).
Conclusions :
Other studies have reported a similar specificity but a higher sensitivity for the detection of strabismus than the current study. While the current study is limited by a small number of strabismic subjects, Spot may be significantly under referring for strabismus in pediatric patients.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.