Facial Nerve Injury during External Dacryocystorhinostomy M. Reza Vagefi, MD, 1 Bryan J. Winn, MD, 2 Chun Cheng Lin, MD, 3 Bryan S. Sires, MD, PhD, 2 Steven J. LauKaitis, MD, 2 Richard L. Anderson, MD, 3 John D. McCann, MD, PhD 3 Objective: To describe weakness of the orbicularis oculi muscle after external dacryocystorhinostomy (DCR) and propose an anatomic explanation for the complication. Design: Retrospective, observational study. Participants: Sixteen patients (13 female, 3 male) with a mean age of 60 years (median, 61 years; range, 34 – 85 years). Methods: A retrospective chart review was performed of consecutive patients who had nasolacrimal duct obstruction repair by external DCR. Patients were identified who developed postoperative orbicularis oculi muscle weakness that manifested as hypometric blink or lagophthalmos with or without punctate keratopathy on the operated side. Patient parameters collected included demographic data, type of incision, incision length, use of lacrimal stent, length of follow-up, intraoperative and postoperative complications, and time to resolution of clinical findings. Statistical analysis was performed using a 2-tailed Fisher exact test with clinical significance designated at  = 0.05. Main Outcome Measures: Identification of patients with orbicularis oculi muscle weakness after external DCR, documentation of incision type, clinical findings, and recovery of function. Results: Among 215 patients and 247 surgeries, 16 individuals (7.4%) were identified who demonstrated abnormalities of eyelid closure in the postoperative period after external DCR. Of these, 13 patients had lagophthalmos with or without hypometric blink and 3 patients had hypometric blink alone. Eleven patients underwent surgery through a nasojugal incision, 4 patients underwent surgery through a vertical incision, and 1 patient underwent surgery through an eyelid margin incision. The degree of postoperative lagoph- thalmos was on average 1.5 mm. Four patients developed punctate keratopathy. Follow-up ranged from 3 to 50 weeks (mean, 20 weeks). Resolution of lagophthalmos was seen on average by 14 weeks with the longest time to resolution of 32 weeks. Three individuals continued to have residual hypometric blink at the time of last follow-up. Conclusions: Damage to peripheral fibers of the zygomatic and buccal branches of the facial nerve as they course through the medial canthal area to innervate the upper eyelid orbicularis oculi muscle may occur during external DCR surgery. Such injury may be responsible for orbicularis oculi muscle weakness manifesting as postoperative abnormal eyelid closure and lagophthalmos. In our cohort of patients, these findings were temporary and typically resolved in several months. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Ophthalmology 2009;xx:xxx © 2009 by the American Academy of Ophthalmology. External dacryocystorhinostomy (DCR) is a commonly per- formed procedure associated with a success rate of greater than 90%. 1–7 Since its first modern description by Toti in 1904, advancements in surgical technique have improved out- comes and decreased morbidity. 8,9 Nevertheless, intraoperative and postoperative complications after DCR surgery occur. 10 Bleeding is the most common intraoperative complication be- cause of the close relation of the surgical site to the angular vessels and the nasal mucosa. Orbital hemorrhage from dis- ruption of the anterior ethmoidal artery or cerebrospinal fluid leak from violation of the cribriform plate may occur. 11,12 Other uncommon intracranial complications have been re- ported, including meningitis and pneumocephalus. 13,14 A range of postoperative complications can be encoun- tered. 10,15 Postoperative bleeding is usually self-limited and rarely significant in nature. Surgical failure is the most frequent complication and is typically caused by scarring at the rhinostomy site or secondary stenosis of the canalicular system. Operative trauma and postoperative inflammation can contribute to unsuccessful surgery. The use of silicone stents may, on occasion, lead to acute and chronic allergic reactions, as well as canalicular erosion. 16 –18 Poor incision healing can lead to scar formation, and the semi-sterile nature of nasal surgery lends to the possibility of wound infection. 19 Although less commonly seen, incision necrosis can occur from aggressive cauterization during surgery and lipogranuloma formation from reaction to antibiotic-coated intranasal gauze. 20,21 The most common external DCR incision is 1.0 to 1.5 cm in length and is placed tangentially to the inferonasal rim of the orbit vertically along the nose approximately 1.0 cm medial to the insertion of the medial canthal tendon (Fig 1). 10,22 Varia- 1 © 2009 by the American Academy of Ophthalmology ISSN 0161-6420/09/$–see front matter Published by Elsevier Inc. doi:10.1016/j.ophtha.2008.09.050 ARTICLE IN PRESS