One of the many things that make management of strabismus interesting is the relative unpredictability of surgical outcome. Although Dieffenbach performed the first documented surgical procedure for strabismus in 1839, and despite long experience of ophthalmologists with this problem, it is still difficult to predict alignment after surgery.

Many solutions have been proposed to improve this state of affairs. Tables of recommended surgical dosages are widely available. Adjustable sutures are generally used in adult strabismus surgery since their popularisation by Jampolsky and others1^–3 in the late 1970s. Others have used biometry to assess the anatomical equator to allow more accurate determination of suture placement.4 Others have measured the angle of strabismus under standard …