Silent sinus syndrome: One more reason for an ophthalmologist to have a rhinologist as a good friend.

Silent sinus syndrome (SSS) is a rare condition involving the maxillary sinus, characterized by unilateral collapse of the maxillary sinus and orbital floor, associated with negative antral pressure in the absence of sinus symptoms 1, . It is also known as imploding antrum syndrome and typical radiological findings are ipsilateral depression of the orbital floor and opacification of a collapsed maxillary sinus 1, . There has been some more than 105 cases of SSS published in English literature so far (1). The largest case series with 22 patients was published by Kass et al. 3 in 1997. SSS is characterized by spontaneous and progressive enophthalmos (“sunken” eye-eye recession into globe) and hypoglobus (globe displaced downward; a drop in the pupillary level), so it is common that these patients first present to ophthalmologist 1, 2, . Its development is gradual and progressive, so after a few months up to a few years may become symptomatic . Since patients present with ophthalmological complains, without any nasal or sinus symptoms, with painless course and slow development, the term “silent sinus” was introduced . The first report of this entity was in 1964 in a paper written by Montgomery . His report was about patients who had diplopia and enophthalmos associated with collapse of the maxillary sinus. Wilkins and Kulwin , in their paper published in 1981, emphasized that there was no orbital trauma in patients as a cause of the clinical simptoms and signs, although up till then it was known it happens only as a consequence of orbital trauma. Soparkar et al. , in their paper published in 1994, introduced the term silent sinus syndrome. They described a large group of 14 patients with spontaneous, unilateral enophthalmos and hypoglobus associated with “asymptomatic, bone thinning, maxillary sinus disease” [seen on computed tomography (CT) scans]. Imploding antrum syndrome can be primary or secondary. Primary or spontaneous (SSS) is idiopathic, whereas secondary may arise from mid-face trauma (including surgery), rhinosurgery, chronic rhinosinusitis and has also been reported in less than 1% of patients after orbital decompression in Graves ophthalmopathy ( thyroid eye disease) 1, 5, 8, . SSS most commonly presents unilaterally, although there are reports on it being bilateral 4, . It occurs exclusively in maxillary sinus (there is one report about it in the frontal sinus) 1, . SSS presents in the third to forth decades of life and seems to affect both genders equally . The incidence of SSS is similar in the left and right maxillary sinuses (there might be a slight predominance for presenting on the right side – (57%) 4, . The average duration of the progressive, characteristic orbitopathies until presentation is 3 months (range 10 days – 2 years) 5, . Average enophthalmos at presentation is 2,96 mm (± 0.16 mm), average hypoglobus at presentation is 2.78 (± 0.25 mm) 5, 9, . Although mostly observed in adults, there have been reports on SSS in children 9, 13, . The syndrome’s typical constellation of symptoms and signs are: spontaneous, gradual and progressive enophthalmos and hypoglobus (ocular asymmetry – a drop in the pupillary level, deep upper lid sulcus), so patients have a various