Medial Rectus Muscle Injuries Associated With Functional Endoscopic Sinus Surgery Characterization and Management Christine M. Huang, M.S.,* Dale R. Meyer, M.D.,* James R. Patrinely, M.D.,† Charles N. S. Soparkar, M.D., Ph.D.,† Roger A. Dailey, M.D.,‡ Marlon Maus, M.D.,§ Peter A. D. Rubin, M.D., R. Patrick Yeatts, M.D.,¶ Thomas A. Bersani, M.D.,** James W. Karesh, M.D.,†† Andrew R. Harrison, M.D.,‡‡ and Joseph P. Shovlin, M.D.§§ *Albany Medical College, Department of Ophthalmology, Albany, New York; †Plastic Eye Surgery Associates, PLLC, Houston, Texas; ‡Casey Eye Institute, Portland, Oregon; §Wills Eye Hospital, Philadelphia, Pennsylvania; Massachusetts Eye and Ear Infirmary, Boston, Massachusetts; ¶Wake Forest University Eye Center, Winston-Salem, North Carolina; **Eye Plastic and Reconstructive Surgery of CNY, Syracuse, New York; ††Sinai Hospital Baltimore/Krieger Eye Institute, Baltimore, Maryland; ‡‡University of Minnesota, Minneapolis, Minnesota; and §§Geisinger Medical Center, Ophthalmology Clinic, Danville, Pennsylvania, U.S.A. Objective: To characterize and evaluate treatment options for medial rectus muscle (MR) injury associated with functional endoscopic sinus surgery (FESS). Design: Retrospective interventional case series Participants: A total of 30 cases were gathered from 10 centers. Methods: Cases of orbital MR injury associated with FESS surgery were solicited from members of the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) through an e-mail discussion group. Main Outcome Measures: Variables assessed included patient demographics, com- puterized tomography and operative findings, extent of MR injury and entrapment, secondary orbital/ocular injuries, initial and final ocular alignment and ductions, and interventions. Results: A spectrum of MR injury ranging from simple contusion to complete MR transection, with and without entrapment, was observed. Four general patterns of presentation and corresponding injury were categorized. Conclusions: Medial rectus muscle injury as a complication of FESS can vary markedly. Proper characterization and treatment are important, particularly with reference to the degree of direct MR injury (muscle tissue loss) and entrapment. Patients with severe MR disruption can benefit from intervention but continue to show persistent limitation of ocular motility and functional impairment. Prevention and early recognition and treatment of these injuries are emphasized. Functional endoscopic sinus surgery (FESS) has be- come the primary surgical approach for treatment of obstructive sinus disorders. In contrast to many external approaches, the orientation during certain portions of FESS is typically toward the orbit, and inadvertent pen- etration of the orbit (typically through the medial orbit wall) may occur. Complications of FESS have been widely documented, including nasolacrimal duct injury, orbital hemorrhage, optic nerve damage, and extraocular muscle injury. 1–18 Medial rectus muscle (MR) muscle injury, in particular, presents special considerations re- garding initial and long-term treatment. We noted 17 Accepted June 3, 2002. Presented at the Fall Symposium of the American Society of Oph- thalmic Plastic and Reconstructive Surgery, New Orleans, Louisiana, November 2001. Address correspondence and reprint requests to Dr. Dale R. Meyer, Lions Eye Institute, Albany Medical Center, 35 Hackett Blvd., Albany, NY 12208. E-mail meyerd@mail.amc.edu DOI: 10.1097/01.IOP.0000031378.02394.45 Ophthalmic Plastic and Reconstructive Surgery Vol. 19, No. 1, pp 25–37 ©2003 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc. 25