Detection of strabismus by the Spot Vision Screener

Background: The Spot Vision Screener, a new automated screener designed for use in schools and pediatric offices, refers children for strabismus based on the device's measurement of "gaze." We sought to evaluate its ability to detect manifest strabismus of ≥8(Δ) in primary position, which criteria is specified by the 2013 guidelines of the American Association for Pediatric Ophthalmology and Strabismus for detection of amblyopia risk factors by automated vision screeners.

Methods: In this prospective study, new and returning patients seen in the pediatric ophthalmology clinic underwent screening with the Spot Vision Screener (version 1.1.51) prior to a complete examination by a pediatric ophthalmologist. A Research Electronic Data Capture database was created for results of Spot referral status and examination. Patients who were referred by the Spot for gaze were included as test positives. Patients found to have constant strabismus of ≥8(Δ) in primary position by the physician were considered referral positive.

Results: A total of 444 children (average age, 72 months; range, 11-221 months) were included. Of these, 93 (20.9%) met the referral-positive threshold for strabismus criteria on examination by the pediatric ophthalmologist. The sensitivity of the Spot to detect AAPOS-threshold strabismus was 77.17%; the specificity, 93.73%. Positive predictive value was 76.34%; negative predictive value, 94.0%.

Conclusions: The Spot demonstrates good sensitivity and excellent specificity for detecting AAPOS-threshold strabismus.