Enophthalmos due to atelectasis of the maxillary sinus: silent sinus syndrome.

Silent sinus syndrome is a clinical entity with the constellation of progressive enophthalmos and hypoglobus due to gradual collapse of the orbital floor with opacification of the maxillary sinus, in the presence of subclinical maxillary sinusitis. It occurs secondary to maxillary sinus hypoventilation due to obstruction of the ostiomeatal unit. In this paper, a 35-year-old woman with a complaint of asymmetry in her left eye and denting of upper eyelid was reported. In the left eye, upper sulcus was deepened and there was 3-mm hypoglobus. There was no diplopia or restriction of eye movements in any gaze positions. Hertel exophthalmometry revealed a 4-mm enophthalmos on the left eye. Computed tomographic scan of the orbita and paranasal sinuses showed left maxillary sinusitis, air-fluid level, and collapse of left maxillary sinus walls. In addition, inferior bulging in the left orbital floor was also reported. The treatment was a 2-stage operation. In the first stage, she underwent endoscopic septoplasty plus left maxillary antrostomy, and in the second stage, she underwent a subciliary orbital floor repair of the iliac bone resulting in the improvement of the enophthalmos and her cosmetic appearance. Regarding this case, the literature is also reviewed in detail.