Two hundred one children 12 to 35 months of age with untreated IXT meeting the following criteria : ( 1 ) IXT at distance OR constant exotropia at distance and either IXT or exophoria at near , and ( 2 ) 15-prism diopter ( ) or more exodeviation at distance or near by prism and alternate cover test ( PACT ) but at least 10 exodeviation at distance by PACT .