Magnetic resonance imaging of the extraocular muscle path before and after strabismus surgery for a large degree of cyclotorsion induced by macular translocation surgery

To evaluate the changes in the location of the extraocular muscles (EOMs) following strabismus surgery to treat a large degree of torsional diplopia induced by macular translocation surgery. Six consecutive patients who underwent macular translocation surgery with 360A degrees of retinotomy and subsequent strabismus surgery were studied. Magnetic resonance imaging (MRI) was performed before and after the surgery. The angle made by the line connecting the center of the orbit and the center of each rectus muscle and the horizontal was measured. The changes in these angles before and after strabismus surgery were studied. The average rotation of the globe after strabismus surgery was 28A degrees (SD = 7.21; range, 17A degrees-39A degrees). The average measured EOM shift was -0.3A degrees (SD = 8.04; range, -20.4A degrees to 20.2A degrees). Despite large torsional rotation of the globe, there was no corresponding torsional repositioning of the deep paths of the rectus muscles. The paths of the operated muscles were essentially unchanged.