What are the common characteristics of children who pass the Spot Vision (Visual Acuity) Screener but fail Visual Acuity (VA) testing?

From the Guidelines

Children who pass the Spot Vision Screener but fail visual acuity (VA) testing typically have mild to moderate hyperopia (farsightedness), mild astigmatism, or amblyopia. These children often have refractive errors that fall just below the Spot Screener's referral thresholds but still affect functional vision. The Spot Vision Screener primarily detects significant refractive errors and eye misalignment but may miss more subtle visual processing issues or mild refractive errors that still impact a child's ability to see clearly at distance. Children with accommodative insufficiency may also pass automated screening but struggle with standard VA charts, as they can briefly focus during the quick automated test but cannot sustain clear focus during longer VA testing. Additionally, children with visual processing disorders, contrast sensitivity issues, or early keratoconus might show this pattern. This discrepancy highlights why comprehensive vision screening programs should include both automated photoscreening and traditional visual acuity testing to effectively identify children with vision problems that could impact learning and development 1.

Some key points to consider when evaluating children who pass the Spot Vision Screener but fail VA testing include:

• The importance of using high-contrast, standardized optotypes, such as LEA SYMBOLS or HOTV letters, to assess visual acuity in young children 1
• The need to present optotypes in a full line of five whenever possible, with equal spacing and legibility, to accurately assess monocular VA 1
• The potential for forced preferential looking using Teller Acuity Cards to provide an assessment of grating acuity in infants, although this method may overestimate VA obtained by recognition VA methods in children with amblyopia 1
• The importance of considering risk factors for amblyopia, such as uveitis, ptosis, gestational age of less than 30 weeks, and family history of amblyopia or strabismus, when evaluating children who pass the Spot Vision Screener but fail VA testing 1.

Overall, a comprehensive approach to vision screening, including both automated photoscreening and traditional visual acuity testing, is necessary to effectively identify children with vision problems that could impact learning and development.

From the Research

Characteristics of Children who Pass the Spot Vision Screener but Fail VA Testing

• The study 2 found that 6.4% of children failed the Spot Vision Screener (SVS) and 8.3% failed the nurse-administered visual acuity screen (NVAS), with 3.8% overlap between the two.
• The positive predictive value (PPV) of the SVS in identifying amblyogenic risk factors (ARFs) and/or reduced visual acuity (VA) was 70.4%, while the PPV of the NVAS was 60.5% 2.
• A 'hybrid' method combining failed NVAS and failed SVS achieved the highest PPV of 91.0% in detecting ARFs and/or reduced VA, but this approach may risk missing children with sight impairment in the community 2.
• The study 3 evaluated the performance of the Spot Vision Screener in children younger than 3 years and found that it had an overall sensitivity of 89.8% and specificity of 70.4% in detecting amblyopia risk factors.
• The study 4 found that the Spot Vision Screener had a sensitivity of 89.5% and specificity of 76.7% in detecting American Association for Pediatric Ophthalmology and Strabismus guidelines for amblyopia risk factors in school-aged children.
• However, the sensitivity decreased to 80% and the specificity increased to 75.3% with narrower refractive criteria 4.
• The study 2 suggests that a number of children who required ophthalmic intervention were missed if only one screening method was utilized, highlighting the importance of combining multiple screening methods to detect visual disturbances.
• The characteristics of children who pass the Spot Vision Screener but fail VA testing are not explicitly stated in the provided studies, but it can be inferred that these children may have refractive errors or other visual disturbances that are not detected by the Spot Vision Screener alone 2, 4.