he treatment of incomitant strabismus presents many challenges. Often, patients with this prob- lem are adults who require excellent surgical alignment to be free of diplopia and to be able to resume their usual activities. Isolated ocular motor palsies are found in many of these patients, and overacting yoke mus- cles, antagonist muscle contractures, and large amounts of incomitance may be present. Children with incomitant strabismus frequently have abnormal accommodative con- vergence/accommodation ratios, dissociated horizontal divergence (DHD) or dissociated vertical divergence (DVD), or nystagmus blockage (compensation) syndrome, as well as ocular motor palsies. For all patients with incomitant strabismus, standard recessions and resections often yield little benefit. Although reasonable alignment in primary gaze may be attained, undercorrection in the field of gaze of the affect- ed muscle and overcorrection in the opposite field of gaze are common sequelae. The use of asymmetric bilateral surgery has been suggested, but often cannot produce the large shifts in comitance required in many patients. The key to the successful management of many forms of incomitant strabismus lies in the weakening of an over- acting yoke muscle in its field of action. Cuppers 1 was the first to describe the posterior fixation suture technique (fadenoperation) to accomplish this goal (Figure 1). With the change of the moment arm of the muscle, rather than simply the shift of the muscle’s length-tension curve (as in a standard recession or resection), the fadenoperation selec- tively weakens the muscle in its field of action, with little effect on other gaze positions. As a result, many strabismus surgeons use the fadenoperation in the treatment of motil- ity disorders with incomitance and maybe combine it with a recession so that there are less amounts of weakening in other gaze positions. Suggested indications include its use Combined Resection and Recession of a Single Rectus Muscle for the Treatment of Incomitant Strabismus Charles J. Bock, Jr , MD, Edwar d G. Buckley , MD, and Shar on F . Fr eedman, MD Background: The treatment of incomitant strabismus is challenging. Traditional approaches include the use of asymmetric bilateral surgery and the fadenoperation (posterior fixation suture). We report our experience with a dif- ferent approach: combined resection and recession of a single rectus muscle. M ethods: The charts of 12 patients who underwent resection of a single rectus muscle with an equal or greater amount of recession of the same mus- cle were identified. In 5 patients, the procedure was performed using the adjustable suture technique, and the adjustment was performed later the same day (Group 1). In the remaining 7 patients, permanent sutures were placed at the time of surgery (Group 2). The procedure was performed for horizontal and vertical gaze incomitance, dissociated horizontal deviation, and distance-near disparity. Results: Four of the 5 patients in Group 1 showed sta- ble, long-term correction of their incomitance, both in primary gaze and in gaze in the direction of the muscle oper- ated on. The results for patients in Group 2 showed stable, long-term correction of incomitance in 3 patients; how- ever, these patients also had slight overcorrections in the direction of gaze opposite to the muscle operated on. An additional patient in Group 2 had a shift of her distance-near disparity, shifting from relatively exotropic to relative- ly esotropic disparity postoperatively. All patients in Group 2 showed at least some decrease in the amount of mea- sured incomitance. We did not encounter complications such as muscle slippage or loss, scleral perforation, or late overcorrection in the field of gaze of the operated muscle. Conclusions: The technique of combined resection and recession of a single rectus muscle shows promise in the treatment of incomitant strabismus. It offers the advan- tages of posterior fixation combined with the greater technical ease of a standard hangback recession. The mus- cle may also be placed on an adjustable suture, allowing for postoperative adjustment in selected patients. (J AAPOS 1999;3:263-8) From the Duke University Eye Center, Durham, North Carolina. Presented in part at the 24th Annual Meeting of the American Association for Pediatric Ophthalmology and Strabismus, Palm Springs, California, 1998. Submitted May 6, 1998. Revision accepted March 15, 1999. Reprint requests: Edward G. Buckley, MD, Duke University Eye Center, Box 3802 DUMC, Durham, NC 27710 (e-mail: BUCKL002@mc.duke.edu). Copyright © 1999 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/99 $8.00 + 0 75/1/101067 Journal of AAPOS October 1999 263 T