Orbital Injury With Medial Rectus Tear and Cerebrospinal Fluid Leak Following Functional Endoscopic Sinus Surgery: A Case Report

Functional endoscopic sinus surgery (FESS) is widely used as a safe and effective treatment for paranasal sinus disorders.However, complications may occur because of the close anatomical relationship between the paranasal sinuses, orbit, and skull base.We report a 32-year-old man with hypertension, diabetes mellitus, and hypercholesterolemia whose earlier FESS had been complicated by left orbital injury with a medial rectus muscle tear.Postoperatively, he developed persistent severe headache requiring daily analgesics, together with restricted motility of the left eye, diplopia, and proptosis, and underwent medial rectus repair four months later.He subsequently developed unilateral left-sided rhinorrhea.Computed tomography demonstrated defects of the left lamina papyracea and thinning of the left lateral lamella, and a cerebrospinal fluid (CSF) leak was suspected despite a magnetic resonance imaging CSF protocol showing no definite leak.Approximately 19 months after the initial surgery, he underwent navigation-guided revision left FESS, which confirmed defects of the lamina papyracea and cribriform plate; the skull base defect was repaired with a nasal floor overlay graft.Following surgery, the headache resolved, with no rhinorrhea, no bleeding, intact vision, and no diplopia.At seven months of follow-up, the patient remains well with no complaints.