Christopher M Bardorf1, John D Baker. 1. Department of Ophthalmology, Children's Hospital of Michigan, Kresge Eye Institute, Wayne State University, Detroit, Michigan, USA.
Abstract
PURPOSE: To evaluate the efficacy of superior oblique muscle split Z-tendon lengthening in the treatment of superior oblique muscle overaction with respect to normalization of superior oblique ductions and versions, reduction of A-pattern strabismus and correction of vertical deviations. In addition, to determine the incidence of complications of the procedure including overcorrection and the effect of the procedure on horizontal deviation. METHODS: A retrospective review was performed of 19 patients who underwent superior oblique muscle split Z-tendon lengthening for A-pattern strabismus or significant vertical deviation associated with superior oblique overaction between June 1980 and September 1999. Ten males and 9 females were included, ranging in age from 2 to 45 years (mean: 9 years). Patients underwent either a unilateral or bilateral superior oblique tendon lengthening based on the patient's clinical picture. RESULTS: Ten of 11 patients (91%) who underwent unilateral tendon lengthening and 10 of 16 eyes (63%) that underwent bilateral superior oblique tendon had complete normalization of superior oblique action. Seven of 10 patients (70%) who underwent unilateral or bilateral tendon lengthening for a clinically significant A-pattern had the A-pattern completely eliminated or brought to a clinically insignificant level. All 8 patients who underwent a unilateral tendon lengthening for a clinically significant vertical deviation had reduction of the vertical deviation. There was no statistically significant effect of either the unilateral or bilateral procedure on horizontal deviation. CONCLUSIONS: The superior oblique muscle split Z-tendon lengthening procedure is highly effective for normalization of superior oblique muscle function and reduction of A-pattern strabismus and vertical deviations associated with superior oblique muscle overaction.
PURPOSE: To evaluate the efficacy of superior oblique muscle split Z-tendon lengthening in the treatment of superior oblique muscle overaction with respect to normalization of superior oblique ductions and versions, reduction of A-pattern strabismus and correction of vertical deviations. In addition, to determine the incidence of complications of the procedure including overcorrection and the effect of the procedure on horizontal deviation. METHODS: A retrospective review was performed of 19 patients who underwent superior oblique muscle split Z-tendon lengthening for A-pattern strabismus or significant vertical deviation associated with superior oblique overaction between June 1980 and September 1999. Ten males and 9 females were included, ranging in age from 2 to 45 years (mean: 9 years). Patients underwent either a unilateral or bilateral superior oblique tendon lengthening based on the patient's clinical picture. RESULTS: Ten of 11 patients (91%) who underwent unilateral tendon lengthening and 10 of 16 eyes (63%) that underwent bilateral superior oblique tendon had complete normalization of superior oblique action. Seven of 10 patients (70%) who underwent unilateral or bilateral tendon lengthening for a clinically significant A-pattern had the A-pattern completely eliminated or brought to a clinically insignificant level. All 8 patients who underwent a unilateral tendon lengthening for a clinically significant vertical deviation had reduction of the vertical deviation. There was no statistically significant effect of either the unilateral or bilateral procedure on horizontal deviation. CONCLUSIONS: The superior oblique muscle split Z-tendon lengthening procedure is highly effective for normalization of superior oblique muscle function and reduction of A-pattern strabismus and vertical deviations associated with superior oblique muscle overaction.