Orbital Apex Syndrome in Pseudomonas Sinusitis After Functional Endoscopic Sinus Surgery.

Sinusitis complicated by orbital apex syndrome is rare. The majority of cases are due to mucormycosis in immunocompromised patients. The authors report a case of orbital apex syndrome secondary to Pseudomonas sinusitis. The patient was a 79-year-old Type 2 diabetic woman who underwent left-sided functional endoscopic sinus surgery. Three months postprocedure, she presented with a 3-week history of gradual vision loss and constant temporal headache on the ipsilateral side. Examination revealed light perception vision, a relative afferent pupillary defect, absent corneal reflex, and disc pallor. Imaging revealed opacification of the posterior ethmoidal air cells extending to involve the orbital apex. Urgent orbital and sinonasal decompression was performed. Intraoperative specimens grew Pseudomonas aeruginosa. The patient was treated with liposomal amphotericin B, posaconazole, and piperacillin/tazobactam. The patient recovered with no visual sequelae. Pseudomonas is an important mimicker to consider in sinusitis causing orbital apex syndrome, and it may occur following functional endoscopic sinus surgery.