Screening for convergence insufficiency in school-age children

Convergence insufficiency (CI) is a common binocular vision disorder which often causes symptoms when doing near work. However, the best screening test for CI is unknown. The purpose of this study was to evaluate the ability of common tests of binocular and accommodative function to identify children with CI in a school screening setting.

Children aged nine to 14 were invited to participate. Positive fusional vergences, near point of convergence (NPC), accommodative amplitude, accommodative facility, Modified Thorington, and the Convergence Insufficiency Symptom Survey were evaluated.

Of the 282 children tested, approximately 20 per cent had 2-3 signs of CI. One half of 2-3 signs of CI and 66 per cent of three signs of CI subjects were symptomatic. Approximately 61 per cent of subjects with symptomatic 2-3 signs of CI had an accompanying low accommodative amplitude. The largest area under the receiver operating characteristic curve was obtained using NPC break measurements. NPC break ≥ 6 cm for CI and NPC break ≥ 7 cm for symptomatic CI were the cut points that maximised the sum of sensitivity and specificity.

NPC break performed best in identifying children with CI.