Testing depth of suppression in childhood intermittent exotropia.

A test of suppression was developed to provide a standardized approach to detecting and grading density of suppression in children with intermittent exotropia when manifestly exotropic. This new Office Suppression Test is a three-step procedure to grade suppression on a 4-point scale (from 0 for "negligible suppression" to 3 for "dense suppression"). The test was performed in 57 children 3-13 years of age with intermittent exotropia (distance angle of 16Δ-35Δ, with spontaneous tropia) during enrollment in a randomized trial. Of the 57 children, 51 could complete testing: 28 (55%) had dense suppression, 12 (24%) had moderate suppression, 5 (10%) had mild suppression, and 6 (12%) had negligible suppression. In a subgroup of 20 untreated children, suppression was evaluated again at 8 weeks. There was moderate agreement between suppression scores at baseline and at 8 weeks (weighted κ = 0.65 [95% CI, 0.45-0.84]).