Case report: We report a case of a large mucocele occurring in a 64-year-old male. The patient presented with severe proptosis and long standing complete visual loss of the left eye. Computer tomography showed a large cystic mass arising from the left fronto-ethmoidal sinus that invaded the orbit and the anterior cranial fossa. Additional ophthalmologic findings were retinal hemorrhages, optic disc swelling, chorio-retinal folds and a complete afferent pupillary defect of the left eye. Surgical management of the mucocele resolved the proptosis and retinal hemorrhages but the visual loss and the chorio-retinal folds persisted.
Discussion: Mucoceles of the periorbital sinus may cause chorio-retinal alterations, optic neuropathy and permanent vision loss.