The effects of surgical technique and the radius of the eye on correction for horizontal strabismus.

A theory is developed that considers the effects of surgical technique and the radius of the eye on the values for the surgical amount that correct horizontal strabismus. By replacing the biologic system of the eye and the extraocular muscles with an idealized model eye, equations are derived that relate to the surgical amount. Using these equations, it is possible to show that small variations in the radius of the eyeball can have a significant effect on the surgical amount. It is also shown that for a recession, variations in the distance between the point where the sutures are tied on the muscle, before disinserting it, and the original insertion point of the muscle can have a significant effect on the final outcome of the surgery.