A diagnosis of basic exotropia
was made, and the patient underwent lateral rectus recession of 7.
Basic exotropia was diagnosed in patients with a difference between distance and near deviation <10 PD.
Unilateral recession of the lateral rectus muscle and resection of the medial rectus muscle were preferred in the patients that had basic exotropia, simulated divergence excess, and convergence insufficiency, whereas bilateral recession of the lateral rectus muscle was preferred in the patients that had true divergence excess.
Exotropia can be divided into three main categories: divergence excess (worse at distance), convergence weakness (worse at near), and basic exotropia
(a significant deviation at both distance and near).