Preoperative Diplopia: The Most Important Prognostic Factor for Diplopia After Surgical Repair of Pure Orbital Blowout Fracture

Background: No consensus exists in the literature regarding the risk factors associated with new or residual diplopia after pure orbital blowout fracture (BOF) repair. Objective: To assess and evaluate the risk factors associated with diplopia after surgical repair of pure BOF. Methods: Patients with pure BOF who were managed surgically were identified in an 11-year period at the McGill University Health Center. The association between new or residual diplopia postsurgical repair and various risk factors was assessed using chi(2) and Fisher exact tests, and multivariate analysis was conducted using logistic regression. Results: A total of 61 patient charts were reviewed. Results demonstrated the presence of preoperative diplopia and radiologic evidence of extraocular muscle (EOM) swelling to be strongly associated with diplopia at 6 months after repair (P < 0.05). Patients who presented preoperatively with diplopia had a 9.91 times greater probability of developing diplopia postoperatively (P = 0.035; 95% confidence interval, 1.17-83.80). Conclusions: Preoperative diplopia is the best predictor of the presence of postoperative diplopia after BOF repair. Initial injury to the EOM leading to EOM swelling and preoperative diplopia seems to be the origin of diplopia after surgical repair of pure BOF.