Screening for amblyogenic factors using a volunteer lay network and the MTI photoscreener. Initial results from 15,000 preschool children in a statewide effort.

ABSTRACT

PURPOSE: To describe the results from a statewide preschool vision screening program using the MTI PhotoScreener (Medical Technology and Innovations, Inc., Cedar Falls, IA). DESIGN: Cross-sectional study. PARTICIPANTS: A total of 15,059 children aged 6 to 47 months enrolled in childcare and preschool settings throughout the state of Tennessee. METHODS: Volunteers from local Lions Clubs took photoscreening photographs of children in a statewide effort. Photographs were interpreted at the Vanderbilt Ophthalmic Photography Reading Center using predetermined criteria. Children who failed the screening were referred to community ophthalmologists or optometrists who performed a comprehensive evaluation and forwarded the results to the authors. MAIN OUTCOME MEASURES: Referral rate, unreadable rate, and predictive value positive (PVP). RESULTS: During the 2 years of the screening program, 15,059 children were screened in 850 screenings. The screening referred 1013 children (6.7%), and 704 photographs (4.7%) were unreadable. Children who failed the screening had a significant abnormality (strabismus, anisometropia, high hypermetropia, high astigmatism, or high myopia) in 320 of the 531 cases where adequate follow-up results were reported. The PVP ranged from 84% when a diagnosis of strabismus was suggested by the photoscreen reading to 41% for astigmatism. Despite intense attention to follow-up, many children who failed the screening never received a formal eye examination. CONCLUSIONS: The MTI PhotoScreener can be used by volunteers to screen preschool children and can have a high PVP in organized settings, provided that meticulous attention is paid to photograph interpretation and quality control. The PVP of the MTI PhotoScreener depends on the diagnosis suggested when the photograph is read. Significant obstacles exist in obtaining care for those who fail screening.