Surgical correction  of esotropia by bilateral medial rectus recession for strabismic angles up to 60 prism diopters is a standard initial therapy. Nevertheless, undercorrection is common and can be difficult to manage. If this occurs, varying strategies exist for the second surgery. Some authors have advocated re-recession of the medial rectus muscle, while others advocated lateral rectus resection .

Re-recession of the MR may result in a late consecutive exotropia in many cases. It is now recognized that placement of the medial rectus muscle to a point greater than 1.5 mm behind the equator results in medial rectus muscle underaction and a greater risk of a consecutive exodeviation.

Many practitioners use their training and prior experience to determine surgical dose, but little objective data exist on the amount of correction obtained with each millimeter of lateral rectus muscle resection. A study measuring the esotropic correction obtained with varying amounts of lateral rectus resection after the medial rectus muscles have been weakened during a prior surgery.