Inferior oblique surgery. Experience at the Mayo Clinic from 1960 to 1981.

Three hundred thirty-seven patients underwent inferior oblique disinsertions at the Mayo Clinic Rochester, Minn, from 1960 to 1981. Versions and hyperdeviations in the primary position were recorded preoperatively and postoperatively. The criteria of a successful result were (1) correction of diplopia, (2) correction of hyperdeviation in the field of action of the inferior oblique, and (3) correction of versions in adduction. Clinical failure was reflected in persistence of hyperdeviation in primary gaze and persistence of overaction of the inferior oblique muscle in adduction. A successful result was found in 88% of primary inferior oblique disinsertions. For secondary inferior oblique overaction, a successful result was found in 72% of patients. We have found that inferior oblique disinsertion is a safe, fast, reliable, and effective weakening procedure with good results.