Repeat Retinomax screening changes positive predictive value

Abstract

Purpose: To quantify changes in autorefraction measurement with repeated readings using the Retinomax autorefractor and to investigate the clinical implications of the results.

Methods: Children referred from a preschool vision screening program for a failed autorefraction screening test received repeat autorefraction as well as a comprehensive eye examination with cycloplegic retinoscopy at later follow-up. The intraclass correlation coefficient between initial and follow-up autorefraction was calculated to quantify changes in repeated measurements to determine whether the second autorefraction significantly changed the predictive value that a referred child would meet case definition. Cases were defined by AAPOS Vision Screening Committee amblyogenic risk factors under cycloplegic retinoscopy.

Results: Repeat Retinomax autorefraction had an intraclass correlation of 0.70 in the right eye and 0.70 in the left eye for mean sphere. Of 636 children who were referred on their initial screening, 169 (26.5%) passed a repeat screening and this subpopulation had 7 cases (4.1%). Of the 467 (73.5%) who again met referral criteria at repeat screening, 268 (57.4%) met case definition. The difference in case rates between these subgroups was highly significant (Fisher exact test, P < 0.001).

Conclusions: There was clinically significant variability when autorefraction measurements were repeated among those referred from initial screening, allowing further risk stratification. In our study cohort, few children who passed repeat screening required further examination. Significant money and overtreatment risk may potentially be avoided by rescreening children who are initially referred from screening evaluations and only examining those who meet referral criteria after a second screening.