Comparing the Test Validity of the Spot Vision Screener using the 2013 and 2021 AAPOS Guidelines for Astigmatism

Abstract

Purpose : Instrument-based pediatric vision screening is commonly utilized in children who are too young to complete visual acuity screening. In 2021, the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) revised their referral guidelines and increased the astigmatism to be detected for children <4 years of age from >2.00D (2013) to >3.00D (2021). The intention was to reduce referrals by increasing the screening/prescribing threshold for astigmatism, due to low risk of amblyopia associated with symmetric moderate astigmatism. We report test validity for astigmatism in infants and toddlers using the 2013 and 2021 referral guidelines.

Methods : Subjects were children aged 12 to <36 months who were screened at a pediatric well-child check using the Welch Allyn Spot Vision Screener and referred for a complete eye exam if they failed the screening based on AAPOS 2013 referral thresholds. The Spot vision screening was repeated at the eye examination prior to assessment of ocular alignment, pupils, anterior segment, motility, the fundus. Cycloplegic retinoscopy was conducted by an experienced retinoscopist who was masked to the Spot results. We compared diagnostic screening validity using the two different guidelines for astigmatism. Screening and exam results were considered positive if either or both eyes had astigmatism above threshold.

Results : One hundred eighty-seven children were referred and completed a cycloplegic examination. Eight were excluded because the Spot was not able to obtain a reading, leaving a total of 178 subjects for analysis. The average age was 20.2 months (SD=6.7, range: 12.2 to 36.0 months) and the female:male ratio was 49:51. See Table 1.

Conclusions : The increase in level of astigmatism for the referral guideline from >2.00D (2013) to >3.00D (2021) resulted in a less sensitive but more specific screening tool. The positive predictive value was lower using the 2021 threshold and negative predictive value was higher. Further research with a sample more representative of the general population of children <4 years of age should be conducted to determine the optimal Spot Vision Screener referral threshold for detection of >3.00D of astigmatism to improve sensitivity for screening for this level of astigmatism.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Table 1: Test Validity using the AAPOS 2013 and 2021 Referral Guideline for Astigmatism