Modified transposition procedure of the vertical recti in sixth nerve palsy

PURPOSE: To report a modified transposition procedure of the vertical recti for severely limited abduction of the globe caused by sixth nerve palsy and to compare this with the Hummelsheim transposition procedure. METHODS: Retrospective study of 13 eyes of 12 patients that had Hummelsheim transposition procedure and 19 eyes of 17 patients that had modified transposition procedure of the vertical recti for severely limited abduction of the globe caused by sixth nerve palsy. The modified transposition procedure joins lateral strips of the vertical recti and sutures this junction to the lateral rectus muscle. Functional results of the Hummelsheim procedure are compared with functional results of the modified transposition procedure. RESULTS: Abductive capacity improved by 4.19 ± 1.67 mm in the Hummelsheim group and 4.08 ± 1.7 mm in the modification. The angle of squint changed from +22.33 ± 6.74 degrees to −0.20 ± 2.61 degrees in the Hummelsheim group and from +25.54 ± 5.66 degrees to +0.95 ± 5.26 degrees in the modification group. The functional results as to abductive capacity and postoperative angle of squint showed no significant difference between the two methods ( P > .05, t test). The modification was less time consuming. CONCLUSIONS: A modification of the transposition techniques of eye muscles in sixth nerve palsy is introduced. Its functional results are comparable to the classic technique of Hummelsheim. Operative risk and trauma are reduced, because the technique avoids scleral stitches and was found to be less time consuming than the Hummelsheim procedure.