Role of near reflex on masking the near angle of deviation of intermittent exotropia & effect of bimedial recti resection on the distance/near differences

The traditional classification of exotropia is based on the distance/near differences. It is not yet solved whether the divergence excess is due to excessive divergence or due to excessive convergence. The study includes 81 patients. 32 patients were indicated for surgery. The angles of XT were measured at far & near as well as on looking outdoors. The angles were re-measured at near with +3D add, after 1-hr monocular occlusion & after prism adaptation test. All patients were subjected to bimedial recti resection between 3-5mm. 20/32 (62.5%) required only one surgery. Larger distant angle is due to excess convergence rather than excessive divergence. Medial rectus resection mimics defective resting tone.