We present the first case of silent sinus syndrome with both normal predisease imaging findings and documented negative maxillary sinus pressure, demonstrating unequivocally the acquired nature and possible etiologic association with negative maxillary sinus pressure in at least some cases of silent sinus syndrome.
A 27-year-old woman with painless, progressive sinking of her right eye over a 3-month period demonstrated 8 mm of enophthalmos and 4 mm of hypoglobus. Computed tomography showed a small, opacified right maxillary sinus with a depressed orbital floor (Figure 1), a new finding, as a magnetic resonance imaging study performed 3 years earlier (for new-onset seizures) was normal (Figure 2).
Computed tomographic scan (axial [left] and coronal [right]) at time of presentation shows marked depression of the right orbital floor with opacification of the right maxillary sinus.
Magnetic resonance imaging study 3 years before presentation shows normal orbits and maxillary sinuses bilaterally (left, anterior; right, posterior).
The patient underwent right orbital floor reconstruction with maxillary antrostomy. Before surgical manipulation, the maxillary os was found to be occluded, and an 18-gauge needle attached to a pressure transducer (model 90602A; SpaceLabs Inc, Redmond, Wash) was inserted into the sinus. A pressure of −23 mm Hg was recorded.
Silent sinus syndrome is spontaneous enophthalmos and hypoglobus associated with a small, ipsilateral maxillary sinus.1 It develops over a course of days to years and is not associated with trauma. At presentation, the maxillary os may be patent or occluded, and the sinus may be partially or completely opacified.
One theory for the development of silent sinus syndrome is as follows. Occlusion of the maxillary sinus os forms an enclosed mucosal space where resorption of air creates negative pressure. Such negative pressure has been recorded in occluded rabbit maxillary sinuses2 and in humans.3 Negative sinus pressure may cause thinning and inward bowing of the sinus walls, including the orbital floor, resulting in hypoglobus. If the maxillary os reopens, the sinus fluid, which initially may have provided some support for the thin orbital floor, may drain, allowing further depression of the orbital floor and globe. This may account for the rapid presentation of some patients, the variable patency of the os, and the variability of sinus fluid.
In the more than 25 cases in our experience, and a nearly equal number in the literature, we are aware of only one case of silent sinus syndrome with normal predisease neuroimaging findings4 and only one report of documented negative sinus pressure.3 Our patient represents the first case of silent sinus syndrome with both normal predisease imaging and documented negative maxillary sinus pressure, demonstrating unequivocally the acquired nature as well as likely etiologic association with negative maxillary sinus pressure in at least some cases of silent sinus syndrome.
Corresponding author: Joseph Davidson, MD, 360 S Mt Auburn Rd, Cape Girardeau, MO 63702-2018 (e-mail: email@example.com).
Davidson JK, Soparkar CNS, Williams JB, Patrinely JR. Negative Sinus Pressure and Normal Predisease Imaging in Silent Sinus Syndrome. Arch Ophthalmol. 1999;117(12):1653-1654. doi: