Purchase this article with an account.
A.J. Rowatt, C.G. Crosby, S.P. Donahue; Screening Preschoolers With Welch Allyn SureSightTM Vision Screener: Methods to Increase the Positive Predictive Value for Astigmatism . Invest. Ophthalmol. Vis. Sci. 2006;47(13):702.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Amblyopia is a common cause of vision loss that may be prevented by early detection and treatment of underlying etiologies. Thus, efforts to screen young children for amblyogenic factors are important. Recently, the vision in preschoolers (VIP) study found that the Welch Allyn SureSightTM Vision Screener (WASS) has the potential to be an effective preschool screening tool. However, a field validation study of the WASS found a high referral rate (11.5%) and low positive predictive value (30%), mostly due to low specificity to detect astigmatism (Donahue and Hudson, AAPOS, March 2006). This project attempted to refine the WASS referral criteria to increase the PPV of preschool vision screening.
As part of an ongoing vision screening program, The Tennessee Lions Outreach Program screened preschoolers for amblyogenic factors with the WASS during the spring of 2005. The WASS referral criteria identified by the VIP study to have 90% specificity were used. Children who were referred by the WASS underwent additional screening with the MTI Photoscreener. If any crescent was present on the MTI photograph, the child was referred for a formal examination including cycloplegic refraction. The standard criteria for "amblyogenic factors" published by the AAPOS Vision Screening Committee were used as exam failure criteria.
Between March and May 2005, 1093 children ages 1– to 5– years old were screened with the WASS. Nine–hundred and fifty–six children (87%) passed the initial screening. Ninety–nine children (9%) were referred from the screening for possible astigmatism and received additional screening with the MTI Photoscreener. Twenty–eight (28%) of these children were also referred from the MTI screening for a formal evaluation. Of these, 67% had amblyogenic factors, principally astigmatism, though anisometropia and high hyperopia were also detected. Thirty–eight children (4%) failed the screening for reasons other than possible astigmatism. In these children, the PPV was slightly higher than 50%. Overall, using the WASS in conjunction with the MTI Photoscreener for those with suspected astigmatism, the PPV was 64%.
The WASS has the potential to be effective in screening preschoolers for amblyogenic factors. Problematic over–referrals can be decreased with appropriate secondary screenings. Future research is needed to help define a more appropriate cutoff level for suspected astigmatism with the WASS.
This PDF is available to Subscribers Only