Abstract
Purpose: :
To detect amblyopia, strabismus or refractive error in children it would be desirable to have a valid, easy-to-use, screening test available at no charge. We developed the Jaeb Visual Acuity Screener (JVAS), a standardized PC-based vision screening algorithm that can be used on any standard computer, administered at a 5-foot distance, and calibrated using a dollar bill. We compared JVAS performance to established automated technology by also screening with the plusoptiX S09 Vision Screener (software version 5.0.8.0) and compared both to a gold-standard exam.
Methods: :
100 consecutive children aged 3 to 7 years (mean 5.8 years) without previous spectacle correction presenting to an eye clinic were screened with the JVAS and plusoptiX, prior to a complete eye examination (gold standard). The JVAS presented 2 large single surround optotypes (HOTV for <7y and e-ETDRS for 7y) and then up to 4 optotypes at an age-appropriate threshold level (3-5y 20/40, 6y 20/32, 7y 20/25). Failure on the JVAS was defined as inability to correctly identify 3 of 4 letters on the age-referenced threshold level. Failure on the plusoptiX was defined based on the manufacturer’s criteria. Failure on the gold standard examination followed published AAPOS criteria, including most recent visual acuity age norms, and cycloplegic Retinomax autorefraction.
Results: :
Testability of screening was high: 100% for JVAS and 98% for plusoptiX. 98 children completed both screening tests. 38 of the 98 children failed the gold standard exam. For the JVAS, sensitivity was 79% and specificity 85%, with a positive predictive value (PPV) of 77% and a negative predictive value (NPV) of 86%. The JVAS compared favorably with the plusoptiX, which had a sensitivity of 82% and specificity 53%, PPV of 53% and NPV of 82%. For the JVAS, the primary reason for false positives and false negatives appeared to be noise in visual acuity assessment. For the plusoptiX, the primary reason for false positives was detecting low levels of astigmatism (which could be adjusted in the future by changing referral criteria) and the reason for false negatives was failure to detect poor visual acuity (which the plusoptiX is not designed to detect).
Conclusions: :
The new JVAS provides a universal standardized screening method for 3- to 7-year-old children using any standard PC. Sensitivity and specificity of the JVAS are comparable to established automated methods for this age range. Providing the new JVAS free of charge to pediatricians and school systems would standardize currently fragmented screening practices.
Keywords: screening for ambylopia and strabismus • amblyopia