Photoscreening for amblyogenic risk factors in 1-year-olds: results from a single center in Portugal over a 9-year period.

Purpose To report the experience of a single center in photoscreening 1-year-olds for amblyogenic risk factors over a 9-year period and to estimate amblyopia prevalence in this population. Methods The records of 11,029 children 11-18 months of age who were screened for amblyogenic risk factors at Centro Hospitalar de Entre o Douro e Vouga between 2004 and 2012 were reviewed. Measurements were performed with MTI (until 2008) and plusoptiX S04 (from 2009). The screening results were evaluated according to criteria adapted from Donahue and colleagues. Results The screening was negative in 8,985 children (82%), positive in 519 (5%), unreadable in 201 (2%), and borderline in 1,324 (12%). The overall positive predictive value (PPV) for the presence of at least one amblyogenic risk factor was 56.8%. The estimated prevalence of meaningful refractive errors in this population was 2.2%; of strabismus, 0.3%. Conclusions The rate of unreadable screenings was low. The overall PPV was lower than other large studies, at older ages, but higher than those of the same-age children. Considering the potential benefits of early intervention in preventing the development of amblyopia, this study demonstrates the feasibility of screening 1-year-olds. [ABSTRACT FROM AUTHOR]