REVIEW URRENT C OPINION
Silent sinus syndrome John H. Pula a and Milap Mehta b
Purpose of review Symptoms of diplopia, abnormal eyelid signs (retraction, ptosis, absent crease), ocular asymmetry (hypoglobus, enophthalmos), and dry eyes from lagophthalmos could all indicate the diagnosis of silent sinus syndrome. It is important for the physician to be updated on this relatively rare clinical entity. Recent findings Silent sinus syndrome lies on a spectrum of other forms of sinus-related orbitopathy. Uncommon presentations and descriptions of sinus involvement other than the maxillary sinus add to the variability of presentation. Radiographic features of disease include an opacified and hypoplastic sinus, a lateralized uncinate process, depression of the orbital floor, and a blocked osteomeatal complex. Management of silent sinus syndrome may include a single or multistage surgical approach, or a nonsurgical approach. Summary This review discusses silent sinus syndrome from a neuro-ophthalmological perspective. Keywords chronic maxillary atelectasis, diplopia, enophthalmos, hypoglobus, silent sinus syndrome
INTRODUCTION
PATHOPHYSIOLOGY
Dr Lawrence Buono [1] reviewed the silent sinus syndrome (SSS) for Current Opinion in Ophthalmology in 2004. In that paper, he summarized the main concepts behind a disease which had been named only 10 years prior. Now, 10 years since his review, further insights into the pathophysiology, clinical presentation, ophthalmologic features, and treatment of SSS have warranted an update. In particular, an increased recognition of myriad neuro-ophthalmologic presentations has made SSS of greater interest to this field. The term silent sinus syndrome originates from a paper by Soparkar et al. [2] who reviewed 19 cases characterized by ‘bone resorption and remodeling of the orbital floor due to otherwise asymptomatic maxillary sinus disease, associated with ipsilateral maxillary sinus hypoplasia, and not fully explained by any...cystic lesion in the maxillary antrum’. Even from this first description, however, controversy over the name ensued. It was suggested that term SSS was arbitrary because it simply represented a spectrum of chronic maxillary sinus disease, independent of whether the patient was symptomatic from sinus disease or not [3]. Despite debate regarding its nomenclature, the concept of the silent syndrome remains important in neuroophthalmology.
Although the exact pathophysiology of SSS is not known, several possible mechanisms have been described. To understand these mechanisms, we first recognize that in SSS there is inward displacement of the sinus walls, and trapping of secretions within them. This secretion trapping leads to impaired ventilation of the sinuses, including at their natural ostium. There continues to be resorption of gas from the sinuses however, which creates a negative pressure gradient. This gradient then leads to the bowing of the sinus walls [4]. However, there are patients with chronic sinusitis who have a closed antrum that do not develop SSS. Must there be another component to the mechanism of disease? A second factor could be a communication between the sinus and the pterygopalatine fossa, in which during the act of mastication a pressure gradient is created, resulting in the wall ‘implosion’ [5]. It is not
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a
Department of Neurology and bDepartment of Ophthalmology, Northshore University Healthsystem, Evanston, Illinois, USA Correspondence John H. Pula, MD, Department of Neurology, Northshore University Healthsystem, 2650 Ridge Ave, Evanston, IL 60201, USA. Tel: +1 847 570 2000; fax: +1 847 570 3500; e-mail: jpula [email protected] Curr Opin Ophthalmol 2014, 25:480–484 DOI:10.1097/ICU.0000000000000106 Volume 25 Number 6 November 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Silent sinus syndrome Pula and Mehta
KEY POINTS Silent sinus syndrome may present to the ophthalmologist as diplopia, eyelid abnormalities (retraction, ptosis, absent crease), ocular asymmetry (hypoglobus, enophthalmos), or dry eye from lagophthalmos. The pathophysiology of SSS occurs from secretion trapping and impaired ventilation of the sinuses, with resorption of gas from the sinus creating a negative pressure gradient. Silent sinus syndrome can be confirmed by radiological findings of maxillary sinus atelectasis with opacification and orbital floor depression. The need for and timing of orbital reconstruction to correct enophthalmos and hypoglobus is controversial. Many experts advocate no orbital reconstruction as there is often significant improvement with sinus surgery alone.
clear whether SSS is a congenitally predisposed condition caused by a developmentally small sinus, but there is evidence to the contrary (at least in some cases), as trauma or surgical (acquired) disturbances of the maxilla or sinus ostium result in SSS [6,7]. In some of these cases, the presence of prolapsed orbital fat causing ethmoidal infundibular obstruction supports this mechanism [8]. In SSS, orbital floor thinning usually leads to hypoglobus. However, in some patients with chronic maxillary sinusitis, there is orbital floor thickening with subsequent proptosis. Why would similar pathologic processes result in different anatomical sequelae? It could be that relative cytokineinduced resorptive activity, sinus pressure, and differing degrees of inflammation determine whether the disease presents with thickened or thinned orbital walls, and their consequences. In general, maxillary sinus-related orbitopathy is best described as a spectrum, of which SSS is one manifestation [9].
PRESENTATION The word ‘silent’ in SSS refers to the absence of typical signs and symptoms of sinusitis. This does not imply that the patient with SSS lacks any symptoms at all. Signs which do occur include painless, slowly progressive unilateral enophthalmos, and hypoglobus (Fig. 1). Although these particular features are nearly universal in SSS, relatively uncommon presentations also include coughing spells [10 ], bilateral involvement [11,12], dry eye disease [13], and dental pain [14]. The ocular surface disease and dry eye in SSS could be attributed to lagophthalmos. Rare involvement of the frontal rather than maxillary sinus can result in hyperglobus instead of hypoglobus [15]. Equally rare involvement of the ethmoid sinus can cause medial displacement of the eye [16,17]. Although the original definition of SSS omitted external causes, this exclusion is perhaps arbitrary, as the same syndrome can occur after myriad secondary causes, including septoplasty with fracturing of the inferior turbinates [18], cosmetic rhinoplasty [19], nasotracheal intubation [20], nasogastric tube insertion [21], or trauma [22]. Nevertheless, when an external factor such as trauma or surgery results in the syndrome, some authors prefer the term maxillary chronic sinus atelectasis as an alternate name to SSS. &
NEURO-OPHTHALMOLOGIC FEATURES As SSS may first present with neuro-ophthalmologic symptoms, it is important for the ophthalmologist to recognize the variable manifestations of the disease. In one case, vertical diplopia was the presenting sign of SSS in a 76-year-old man found to have left hypertropia with a supraduction defect right eye (OD) and 1 mm ptosis OD. The diagnosis of a superior division microvascular cranial nerve 3 (CN3) palsy was made until persistent symptoms over 1 year prompted reevaluation, ultimately leading to the diagnosis of SSS [23 ]. &
FIGURE 1. Clinical presentation of silent sinus syndrome. Patient with right-sided silent sinus syndrome presenting with features of asymmetric eyelid creases and diplopia. (a) High right eyelid crease (arrowhead) with brow compensation (arrow). Pupil light reflexes are vertically asymmetric, with relative hypertropia of the left eye. (b) Centered light reflexes occur with six diopters of base-in and six diopters of base-down prism in the left eye. 1040-8738 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
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Diplopia is a rare side-effect after Botox injections to the face. Ophthalmologists may be consulted in these cases. One report in the plastic surgery literature [24] described the SSS first presenting after an injection of Botox. The Botox correlation turned out to be a red herring. Another report [25] described a patient with episodic vertical diplopia with a left hypertropia. Clinical examination initially suggested a left superior oblique paresis, but radioimaging showed a right SSS, with recession of the right inferior rectus and inferior oblique muscles. The first case of SSS, reported in the neurology literature, described a 42-year-old man with vertical diplopia on upgaze whose examination suggested restriction of left eye supraduction. MRI confirmed left-sided SSS [26], but only after myasthenia gravis was first suspected. Myasthenia gravis was also considered most likely in a 31-year-old man presenting with 6 months of right eye ptosis [27]. The ptosis in SSS is actually a pseudoptosis, resulting from enophthalmos and hypoglobus. However, it is actually more common to have ipsilateral pseudoretraction [28]. These eyelid signs of pseudoretraction and lid lag may be related either to intact levator function in the setting of a prolapsed globe, or to increased firing of the superior division of CN3 in an attempt to balance the mechanical pull inferiorly which thus also activates levator function [29]. As a related sign, the upper eyelid crease may be absent in SSS [30] because of dysfunction of the levator palpebrae superioris muscle secondary to hypoglobus. Although more prevalent in adults, SSS can also present in children. One case described a 9-year old with a history of strabismus surgery presenting with vertical diplopia found to have restriction of the right eye on forced duction testing in upgaze. It was felt that the mechanism of diplopia in such cases is secondary fibrosis of the inferior ocular motor muscles leading to loss of elasticity [31]. However, a 44-year-old man with transient vertical diplopia due to SSS had resolution of diplopia after functional endoscopic sinus surgery (FESS) without orbital floor surgery [29], implying that the muscles may be structurally normal in SSS, with deficits occurring because of other factors.
One study reviewed imaging characteristics of SSS in 14 patients. Eight had right side involvement, representative of the slight increased prevalence of right-sided disease historically reported. No patients had displacement of the orbital roof, although all had depression of the orbital floor with hypoglobus. Radiographic enophthalmos was seen in 11/14. Thickness of the maxillary walls was variably decreased, increased, or normal, but there was universal concavity of the medial and lateral maxilla walls. Sinus opacity was present in all but one patient, and only one patient had significant disease in one of their other sinuses [34].
MANAGEMENT Proper surgical planning of SSS requires both neuroimaging and a physical examination of the eye, orbit, and nose. A nasal examination may demonstrate a septal deformity, a lateralized uncinate process, and an enlarged middle meatus. There are two main goals in the treatment of SSS: first to improve the maxillary sinus drainage and second to restore normal orbital anatomy. The purpose of any sinus procedure is to reestablish the drainage of the maxillary sinus, ensure the patency of the maxillary ostium, aspirate any residual secretions from the sinus, and culture the
RADIOGRAPHIC FEATURES Both computed tomography (CT) and MRI can be diagnostic for SSS, as they both include adequate views of the orbits and maxillary sinuses [32 ]. Imaging often demonstrates an opacified and hypoplastic maxillary sinus, a lateralized uncinate process, depression of the orbital floor, and a blocked osteomeatal complex (Fig. 2) [33,34]. &
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FIGURE 2. Radiographic appearance of silent sinus syndrome. Coronal CT showing typical features of silent sinus syndrome. Maxillary sinus is opacified with hypoglobus (double arrow). Oblique line represents expected anatomical orbital floor landmark. Volume 25 Number 6 November 2014
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Silent sinus syndrome Pula and Mehta
secretions [35]. The Caldwell-Luc was commonly used in the past but has become supplanted by FESS as the treatment of choice [36]. FESS may begin with a septoplasty to improve access to the more superiorly and laterally located structures. Next, an uncinectomy may be performed to gain access to the maxillary drainage system or osteomeatal complex. Once the uncinate process is removed, the maxillary ostium is often visible. Finally, a wide maxillary or middle-meatal antrostomy is performed to enlarge the maxillary sinus ostium. The physiologic ostium is identified and the area is enlarged circumferentially to include the maxillary sinus ostium [37]. A balloon sinuplasty has recently been described as a less invasive, alternative option to treat SSS by correcting the uncinate process position, and enlarging the maxillary sinus ostium without drilling [38 ]. The need for and timing of orbital reconstruction to correct enophthalmos and hypoglobus are controversial. There are three options for timing, including a single-stage operation with the FESS, a two-stage approach 2–6 months after FESS, and no orbital reconstruction with FESS. Many authors advocate no orbital reconstruction as there is often significant improvement with sinus surgery alone [39,40,41 ]. Sivasubramanian demonstrated 22 of 23 patients having either resolution of symptoms with endoscopic sinus surgery alone and only one requiring second-stage orbital reconstruction [41 ]. Cardesin advocated a single-surgical step for endoscopic surgery and orbital reconstruction [42]. The single-stage approach has the potential advantages of avoiding morbidities associated with a second hospital stay and second anesthesia event [42]. A two-stage approach has the potential advantages of avoiding placing an orbital implant in an infectious process and avoiding overcorrecting the globe position [43]. Thomas demonstrated two of four patients requiring second-stage orbital reconstruction with two other patients requiring only endoscopic sinus surgery [43]. However, Behbehani demonstrated that most microbiology cultures in SSS were negative for any infectious process [44]. There are multiple implant options for floor reconstruction, including both alloplastic materials and autogenous grafts. Alloplastic options include titanium plates, polyethylene implants, hydroxyapatite implants, supramid sheets, nylon sheets, and silicone implants [42,45]. Autogenous sources of reconstructive grafts include septal cartilage, split calvarial bone grafts, and costochondral cartilage [42,45,46]. The basic surgical principle for orbital floor reconstruction is similar to the approach for orbital floor fracture repair [45,46]. The process involves either a transconjunctival or a subciliary approach to the inferior orbit [45,46]. After the &
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orbital rim is identified, the implant of choice is positioned over the depressed orbital floor. Often, the orbital rim is not as significantly involved as the rest of the orbital floor and provides a stable structure upon which to fixate the floor implant [45,46]. Finally, a nonsurgical approach for treating residual enophthalmos after FESS was described by Mavrikakis [46]. The authors injected 2 ml of hyaluronic acid gel into the intraconal and extraconal spaces to improve the globe position with stable results for 6 months [46]. This straightforward and safe technique offers another option to treat enophthalmos after sinus surgery but may not change hypoglobus.
CONCLUSION The physician should recognize that an overlapping spectrum of disease exists among different organ systems. The eye has long been considered a window for finding disease occurring elsewhere in the body. In the case of SSS, disease in the eyes intersects with disease in the nasal cavity. When searching for the cause of ocular problems on MRI, it is important not only to examine the orbits and brain, but also the sinuses. The SSS is a clinical entity which reminds us to occasionally look beyond our own specialty of medicine in order to find the cause of symptoms within it. Acknowledgements The authors wish to thank Mrs Connie Johnson for her assistance in acquiring references. Conflicts of interest There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. Buono LM. The silent sinus syndrome: maxillary sinus atelectasis with enophthalmos and hypoglobus. Curr Opin Ophthalmol 2004; 15:486–489. 2. Soparkar CN, Patrinely JR, Cuaycong MJ, et al. The silent sinus syndrome. A cause of spontaneous enophthalmos. Ophthalmology 1994; 101:772–778. 3. Langer PD, Patel BC, Anderson RL. Silent sinus syndrome. Ophthalmology 1994; 101:1763–1764. 4. Cobb AR, Murthy R, Cousin GC, et al. Silent sinus syndrome. Br J Oral Maxillofac Surg 2012; 50:e81–e85. 5. Baujat B, Derbez R, Rossarie R, et al. Silent sinus syndrome: a mechanical theory. Orbit 2006; 25:145–148. 6. Hourany R, Aygun N, Della Santina CC, Zinreich SJ. Silent sinus syndrome: an acquired condition. AJNR Am J Neuroradiol 2005; 26:2390–2392. 7. Ross JJ, Kersten RC. Late enophthalmos mimicking silent sinus syndrome secondary to orbital trauma. J Craniofac Surg 2005; 16:840–843. 8. Rose GE, Lund VJ. Clinical features and treatment of late enophthalmos after orbital decompression: a condition suggesting cause for idiopathic ‘imploding antrum’ (silent sinus) syndrome. Ophthalmology 2003; 110:819–826. 9. Warwar RE, Rogers DL. Exophthalmos and orbital floor thickening related to maxillary sinusitis. Ophthal Plast Reconstr Surg 2003; 19:158–159.
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Neuro-ophthalmology 10. Guillen DE, Pinargote PM, Guarderas JC. The silent sinus syndrome: protean manifestations of a rare upper respiratory disorder revisited. Clin Mol Allergy 2013; 11:5. The authors provide a case report of a patient with coughing spells as the presenting symptom of SSS, and whose CT suggested chronic rhinosinusitis. 11. Suh JD, Ramakrishnan V, Lee JY, Chiu AG. Bilateral silent sinus syndrome. Ear Nose Throat J 2012; 91:E19–E21. 12. Ferri A, Ferri T, Sesenna E. Bilateral silent sinus syndrome: case report and surgical solution. J Oral Maxillofac Surg 2012; 70:e103–e106. 13. Liss JA, Patel RD, Stefko ST. A case of bilateral silent sinus syndrome presenting with chronic ocular surface disease. Ophthal Plast Reconstr Surg 2011; 27:e158–e160. 14. Facon F, Eloy P, Brasseur P, et al. The silent sinus syndrome. Eur Arch Otorhinolaryngol 2006; 263:567–571. 15. Naik RM, Khemani S, Saleh HA. Frontal silent sinus syndrome. Otolaryngol Head Neck Surg 2013; 148:354–355. 16. McArdle B, Perry C. Ethmoid silent sinus syndrome causing inward displacement of the orbit: case report. J Laryngol Otol 2010; 124:206–208. 17. Braganza A, Khooshabeh R. Ethmoidal involvement in ‘imploding’ (silent) sinus syndrome. Ophthal Plast Reconstr Surg 2005; 21:305–307. 18. Jung D, Gray ST. Silent sinus syndrome after lateral fracture of the inferior turbinate. Otolaryngol Head Neck Surg 2012; 146:863–864. 19. Eloy JA, Jacobson AS, Elahi E, Shohet MR. Enophthalmos as a complication of rhinoplasty. Laryngoscope 2006; 116:1035–1038. 20. Hobbs CG, Saunders MW, Potts MJ. ‘Imploding antrum’ or silent sinus syndrome following naso-tracheal intubation. Br J Ophthalmol 2004; 88:974–975. 21. Hobbs CG, Saunders MW, Potts MJ. Spontaneous enophthalmos: silent sinus syndrome. J Laryngol Otol 2004; 118:310–312. 22. Montezuma SR, Gopal H, Savar A, et al. Silent sinus syndrome presenting as enophthalmos long after orbital trauma. J Neuroophthalmol 2008; 28:107– 110. 23. Saffra N, Rakhamimov A, Saint-Louis LA, Wolintz RJ. Acute diplopia as the & presenting sign of silent sinus syndrome. Ophthal Plast Reconstr Surg 2013; 29:e130–e131. The authors present the first case of acute vertical diplopia as the presenting symptom of SSS. 24. Singh KA, Barber WB 2nd, Codner MA. Silent sinus syndrome: a rare presentation after botulinum toxin injection. Aesthet Surg J 2011; 31:181–183. 25. Zhang C, Phamonvaechavan P, Christoff A, Guyton DL. Silent sinus syndrome causing cyclovertical diplopia masquerading as superior oblique paresis in the fellow eye. J AAPOS 2010; 14:450–452. 26. Stevens K, Omer S, Toocaram B, et al. The imploding antrum syndrome: an unusual cause of double vision. Pract Neurol 2010; 10:101–104. 27. Kaeser PF, Borruat FX. Acquired unilateral pseudoptosis: a presentation of silent sinus syndrome. Klin Monbl Augenheilkd 2006; 223:409–411. 28. Burroughs JR, Herna´ndez Cospı´n JR, Soparkar CN, Patrinely JR. Misdiagnosis of silent sinus syndrome. Ophthal Plast Reconstr Surg 2003; 19:449– 454. 29. Wan MK, Francis IC, Carter PR, et al. The spectrum of presentation of silent sinus syndrome. J Neuroophthalmol 2000; 20:207–212. &
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30. Toh T, Weatherhead RG. Absent upper eyelid skin crease: a sign of hypoglobus. Clin Experiment Ophthalmol 2005; 33:539–540. 31. Yip CC, McCulley TJ, Kersten RC, et al. Silent sinus syndrome as a cause of diplopia in a child. J Pediatr Ophthalmol Strabismus 2003; 40:309–311. 32. Gaudino S, Di Lella GM, Piludu F, et al. CT and MRI diagnosis of silent sinus & syndrome. Radiol Med 2013; 118:265–275. Concludes that both CT and MRI can establish a diagnosis of SSS, but CT provides a better analysis of features of SSS necessary for diagnosis and differentiation from other sinus conditions. 33. Kass ES, Salman S, Rubin PA, et al. Chronic maxillary atelectasis. Ann Otol Rhinol Laryngol 1997; 106:109–116. 34. Rose GE, Sandy C, Hallberg L, Moseley I. Clinical and radiologic characteristics of the imploding antrum, or ‘silent sinus’ syndrome. Ophthalmology 2003; 110:811–818. 35. Bossolesi P, Autelitano L, Brusati R, Castelnuovo P. The silent sinus syndrome: diagnosis and surgical treatment. Rhinology 2008; 46:308–316. 36. Jacob KJ, George S, Preethi S, Arunraj VS. A comparative study between endoscopic middle meatal antrostomy and Caldwell-Luc surgery in the treatment of chronic maxillary sinusitis. Indian J Otolaryngol Head Neck Surg 2011; 63:214–219. 37. Senior BA, Kennedy DW, Tanabodee J, et al. Long-term results of functional endoscopic sinus surgery. Laryngoscope 1998; 108:151–157. 38. Kilty SJ. Maxillary sinus atelectasis (silent sinus syndrome): treatment with & balloon sinuplasty. J Laryngol Otol 2014; 128:189–191. Balloon sinuplasty is a less invasive, alternative option to treat SSS by correcting the uncinate process position, and by enlarging the maxillary sinus ostium without drilling. 39. Yiotakis I, Papanikolaou V, Alatzidou Z, et al. Silent sinus syndrome, a case presentation. Rhinology 2005; 43:313–315. 40. Sivasubramaniam R, Sacks R, Thornton M. Silent sinus syndrome: dynamic changes in the position of the orbital floor after restoration of normal sinus pressure. J Laryngol Otol 2011; 125:1239–1243. 41. Cardesin A, Escamilla Y, Romera M, et al. Single surgical step for endoscopic & surgery and orbital reconstruction of a silent sinus syndrome. Acta Otorrinolaringol Esp 2013; 64:297–299. The authors advocate for single surgical step for endoscopic surgery and orbital reconstruction. The single-stage approach has the potential advantages of avoiding morbidities associated with a second hospital stay and second anesthesia event. 42. Thomas RD, Graham SM, Carter KD, et al. Management of the orbital floor in silent sinus syndrome. Am J Rhinol 2003; 17:97–100. 43. Behbehani R, Vacareza N, Bilyk JR, et al. Simultaneous endoscopic antrostomy and orbital reconstruction in silent sinus syndrome. Orbit 2006; 25:97– 101. 44. Annino DJ, Goguen LA. Silent sinus syndrome. Curr Opin Otolaryngol Head Neck Surg 2008; 16:22–25. 45. Dailey RA, Cohen JI. Surgical repair of the silent sinus syndrome. Ophthal Plast Reconstr Surg 1995; 11:261–268. 46. Mavrikakis I, Detorakis ET, Yiotakis I, Kandiloros D. Nonsurgical management of silent sinus syndrome with hyaluronic acid gel. Ophthal Plast Reconstr Surg 2012; 28:e6–e7.
Volume 25 Number 6 November 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Silent sinus syndrome John H. Pula a and Milap Mehta b
Purpose of review Symptoms of diplopia, abnormal eyelid signs (retraction, ptosis, absent crease), ocular asymmetry (hypoglobus, enophthalmos), and dry eyes from lagophthalmos could all indicate the diagnosis of silent sinus syndrome. It is important for the physician to be updated on this relatively rare clinical entity. Recent findings Silent sinus syndrome lies on a spectrum of other forms of sinus-related orbitopathy. Uncommon presentations and descriptions of sinus involvement other than the maxillary sinus add to the variability of presentation. Radiographic features of disease include an opacified and hypoplastic sinus, a lateralized uncinate process, depression of the orbital floor, and a blocked osteomeatal complex. Management of silent sinus syndrome may include a single or multistage surgical approach, or a nonsurgical approach. Summary This review discusses silent sinus syndrome from a neuro-ophthalmological perspective. Keywords chronic maxillary atelectasis, diplopia, enophthalmos, hypoglobus, silent sinus syndrome
INTRODUCTION
PATHOPHYSIOLOGY
Dr Lawrence Buono [1] reviewed the silent sinus syndrome (SSS) for Current Opinion in Ophthalmology in 2004. In that paper, he summarized the main concepts behind a disease which had been named only 10 years prior. Now, 10 years since his review, further insights into the pathophysiology, clinical presentation, ophthalmologic features, and treatment of SSS have warranted an update. In particular, an increased recognition of myriad neuro-ophthalmologic presentations has made SSS of greater interest to this field. The term silent sinus syndrome originates from a paper by Soparkar et al. [2] who reviewed 19 cases characterized by ‘bone resorption and remodeling of the orbital floor due to otherwise asymptomatic maxillary sinus disease, associated with ipsilateral maxillary sinus hypoplasia, and not fully explained by any...cystic lesion in the maxillary antrum’. Even from this first description, however, controversy over the name ensued. It was suggested that term SSS was arbitrary because it simply represented a spectrum of chronic maxillary sinus disease, independent of whether the patient was symptomatic from sinus disease or not [3]. Despite debate regarding its nomenclature, the concept of the silent syndrome remains important in neuroophthalmology.
Although the exact pathophysiology of SSS is not known, several possible mechanisms have been described. To understand these mechanisms, we first recognize that in SSS there is inward displacement of the sinus walls, and trapping of secretions within them. This secretion trapping leads to impaired ventilation of the sinuses, including at their natural ostium. There continues to be resorption of gas from the sinuses however, which creates a negative pressure gradient. This gradient then leads to the bowing of the sinus walls [4]. However, there are patients with chronic sinusitis who have a closed antrum that do not develop SSS. Must there be another component to the mechanism of disease? A second factor could be a communication between the sinus and the pterygopalatine fossa, in which during the act of mastication a pressure gradient is created, resulting in the wall ‘implosion’ [5]. It is not
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a
Department of Neurology and bDepartment of Ophthalmology, Northshore University Healthsystem, Evanston, Illinois, USA Correspondence John H. Pula, MD, Department of Neurology, Northshore University Healthsystem, 2650 Ridge Ave, Evanston, IL 60201, USA. Tel: +1 847 570 2000; fax: +1 847 570 3500; e-mail: jpula [email protected] Curr Opin Ophthalmol 2014, 25:480–484 DOI:10.1097/ICU.0000000000000106 Volume 25 Number 6 November 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Silent sinus syndrome Pula and Mehta
KEY POINTS Silent sinus syndrome may present to the ophthalmologist as diplopia, eyelid abnormalities (retraction, ptosis, absent crease), ocular asymmetry (hypoglobus, enophthalmos), or dry eye from lagophthalmos. The pathophysiology of SSS occurs from secretion trapping and impaired ventilation of the sinuses, with resorption of gas from the sinus creating a negative pressure gradient. Silent sinus syndrome can be confirmed by radiological findings of maxillary sinus atelectasis with opacification and orbital floor depression. The need for and timing of orbital reconstruction to correct enophthalmos and hypoglobus is controversial. Many experts advocate no orbital reconstruction as there is often significant improvement with sinus surgery alone.
clear whether SSS is a congenitally predisposed condition caused by a developmentally small sinus, but there is evidence to the contrary (at least in some cases), as trauma or surgical (acquired) disturbances of the maxilla or sinus ostium result in SSS [6,7]. In some of these cases, the presence of prolapsed orbital fat causing ethmoidal infundibular obstruction supports this mechanism [8]. In SSS, orbital floor thinning usually leads to hypoglobus. However, in some patients with chronic maxillary sinusitis, there is orbital floor thickening with subsequent proptosis. Why would similar pathologic processes result in different anatomical sequelae? It could be that relative cytokineinduced resorptive activity, sinus pressure, and differing degrees of inflammation determine whether the disease presents with thickened or thinned orbital walls, and their consequences. In general, maxillary sinus-related orbitopathy is best described as a spectrum, of which SSS is one manifestation [9].
PRESENTATION The word ‘silent’ in SSS refers to the absence of typical signs and symptoms of sinusitis. This does not imply that the patient with SSS lacks any symptoms at all. Signs which do occur include painless, slowly progressive unilateral enophthalmos, and hypoglobus (Fig. 1). Although these particular features are nearly universal in SSS, relatively uncommon presentations also include coughing spells [10 ], bilateral involvement [11,12], dry eye disease [13], and dental pain [14]. The ocular surface disease and dry eye in SSS could be attributed to lagophthalmos. Rare involvement of the frontal rather than maxillary sinus can result in hyperglobus instead of hypoglobus [15]. Equally rare involvement of the ethmoid sinus can cause medial displacement of the eye [16,17]. Although the original definition of SSS omitted external causes, this exclusion is perhaps arbitrary, as the same syndrome can occur after myriad secondary causes, including septoplasty with fracturing of the inferior turbinates [18], cosmetic rhinoplasty [19], nasotracheal intubation [20], nasogastric tube insertion [21], or trauma [22]. Nevertheless, when an external factor such as trauma or surgery results in the syndrome, some authors prefer the term maxillary chronic sinus atelectasis as an alternate name to SSS. &
NEURO-OPHTHALMOLOGIC FEATURES As SSS may first present with neuro-ophthalmologic symptoms, it is important for the ophthalmologist to recognize the variable manifestations of the disease. In one case, vertical diplopia was the presenting sign of SSS in a 76-year-old man found to have left hypertropia with a supraduction defect right eye (OD) and 1 mm ptosis OD. The diagnosis of a superior division microvascular cranial nerve 3 (CN3) palsy was made until persistent symptoms over 1 year prompted reevaluation, ultimately leading to the diagnosis of SSS [23 ]. &
FIGURE 1. Clinical presentation of silent sinus syndrome. Patient with right-sided silent sinus syndrome presenting with features of asymmetric eyelid creases and diplopia. (a) High right eyelid crease (arrowhead) with brow compensation (arrow). Pupil light reflexes are vertically asymmetric, with relative hypertropia of the left eye. (b) Centered light reflexes occur with six diopters of base-in and six diopters of base-down prism in the left eye. 1040-8738 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
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481
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Diplopia is a rare side-effect after Botox injections to the face. Ophthalmologists may be consulted in these cases. One report in the plastic surgery literature [24] described the SSS first presenting after an injection of Botox. The Botox correlation turned out to be a red herring. Another report [25] described a patient with episodic vertical diplopia with a left hypertropia. Clinical examination initially suggested a left superior oblique paresis, but radioimaging showed a right SSS, with recession of the right inferior rectus and inferior oblique muscles. The first case of SSS, reported in the neurology literature, described a 42-year-old man with vertical diplopia on upgaze whose examination suggested restriction of left eye supraduction. MRI confirmed left-sided SSS [26], but only after myasthenia gravis was first suspected. Myasthenia gravis was also considered most likely in a 31-year-old man presenting with 6 months of right eye ptosis [27]. The ptosis in SSS is actually a pseudoptosis, resulting from enophthalmos and hypoglobus. However, it is actually more common to have ipsilateral pseudoretraction [28]. These eyelid signs of pseudoretraction and lid lag may be related either to intact levator function in the setting of a prolapsed globe, or to increased firing of the superior division of CN3 in an attempt to balance the mechanical pull inferiorly which thus also activates levator function [29]. As a related sign, the upper eyelid crease may be absent in SSS [30] because of dysfunction of the levator palpebrae superioris muscle secondary to hypoglobus. Although more prevalent in adults, SSS can also present in children. One case described a 9-year old with a history of strabismus surgery presenting with vertical diplopia found to have restriction of the right eye on forced duction testing in upgaze. It was felt that the mechanism of diplopia in such cases is secondary fibrosis of the inferior ocular motor muscles leading to loss of elasticity [31]. However, a 44-year-old man with transient vertical diplopia due to SSS had resolution of diplopia after functional endoscopic sinus surgery (FESS) without orbital floor surgery [29], implying that the muscles may be structurally normal in SSS, with deficits occurring because of other factors.
One study reviewed imaging characteristics of SSS in 14 patients. Eight had right side involvement, representative of the slight increased prevalence of right-sided disease historically reported. No patients had displacement of the orbital roof, although all had depression of the orbital floor with hypoglobus. Radiographic enophthalmos was seen in 11/14. Thickness of the maxillary walls was variably decreased, increased, or normal, but there was universal concavity of the medial and lateral maxilla walls. Sinus opacity was present in all but one patient, and only one patient had significant disease in one of their other sinuses [34].
MANAGEMENT Proper surgical planning of SSS requires both neuroimaging and a physical examination of the eye, orbit, and nose. A nasal examination may demonstrate a septal deformity, a lateralized uncinate process, and an enlarged middle meatus. There are two main goals in the treatment of SSS: first to improve the maxillary sinus drainage and second to restore normal orbital anatomy. The purpose of any sinus procedure is to reestablish the drainage of the maxillary sinus, ensure the patency of the maxillary ostium, aspirate any residual secretions from the sinus, and culture the
RADIOGRAPHIC FEATURES Both computed tomography (CT) and MRI can be diagnostic for SSS, as they both include adequate views of the orbits and maxillary sinuses [32 ]. Imaging often demonstrates an opacified and hypoplastic maxillary sinus, a lateralized uncinate process, depression of the orbital floor, and a blocked osteomeatal complex (Fig. 2) [33,34]. &
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FIGURE 2. Radiographic appearance of silent sinus syndrome. Coronal CT showing typical features of silent sinus syndrome. Maxillary sinus is opacified with hypoglobus (double arrow). Oblique line represents expected anatomical orbital floor landmark. Volume 25 Number 6 November 2014
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Silent sinus syndrome Pula and Mehta
secretions [35]. The Caldwell-Luc was commonly used in the past but has become supplanted by FESS as the treatment of choice [36]. FESS may begin with a septoplasty to improve access to the more superiorly and laterally located structures. Next, an uncinectomy may be performed to gain access to the maxillary drainage system or osteomeatal complex. Once the uncinate process is removed, the maxillary ostium is often visible. Finally, a wide maxillary or middle-meatal antrostomy is performed to enlarge the maxillary sinus ostium. The physiologic ostium is identified and the area is enlarged circumferentially to include the maxillary sinus ostium [37]. A balloon sinuplasty has recently been described as a less invasive, alternative option to treat SSS by correcting the uncinate process position, and enlarging the maxillary sinus ostium without drilling [38 ]. The need for and timing of orbital reconstruction to correct enophthalmos and hypoglobus are controversial. There are three options for timing, including a single-stage operation with the FESS, a two-stage approach 2–6 months after FESS, and no orbital reconstruction with FESS. Many authors advocate no orbital reconstruction as there is often significant improvement with sinus surgery alone [39,40,41 ]. Sivasubramanian demonstrated 22 of 23 patients having either resolution of symptoms with endoscopic sinus surgery alone and only one requiring second-stage orbital reconstruction [41 ]. Cardesin advocated a single-surgical step for endoscopic surgery and orbital reconstruction [42]. The single-stage approach has the potential advantages of avoiding morbidities associated with a second hospital stay and second anesthesia event [42]. A two-stage approach has the potential advantages of avoiding placing an orbital implant in an infectious process and avoiding overcorrecting the globe position [43]. Thomas demonstrated two of four patients requiring second-stage orbital reconstruction with two other patients requiring only endoscopic sinus surgery [43]. However, Behbehani demonstrated that most microbiology cultures in SSS were negative for any infectious process [44]. There are multiple implant options for floor reconstruction, including both alloplastic materials and autogenous grafts. Alloplastic options include titanium plates, polyethylene implants, hydroxyapatite implants, supramid sheets, nylon sheets, and silicone implants [42,45]. Autogenous sources of reconstructive grafts include septal cartilage, split calvarial bone grafts, and costochondral cartilage [42,45,46]. The basic surgical principle for orbital floor reconstruction is similar to the approach for orbital floor fracture repair [45,46]. The process involves either a transconjunctival or a subciliary approach to the inferior orbit [45,46]. After the &
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orbital rim is identified, the implant of choice is positioned over the depressed orbital floor. Often, the orbital rim is not as significantly involved as the rest of the orbital floor and provides a stable structure upon which to fixate the floor implant [45,46]. Finally, a nonsurgical approach for treating residual enophthalmos after FESS was described by Mavrikakis [46]. The authors injected 2 ml of hyaluronic acid gel into the intraconal and extraconal spaces to improve the globe position with stable results for 6 months [46]. This straightforward and safe technique offers another option to treat enophthalmos after sinus surgery but may not change hypoglobus.
CONCLUSION The physician should recognize that an overlapping spectrum of disease exists among different organ systems. The eye has long been considered a window for finding disease occurring elsewhere in the body. In the case of SSS, disease in the eyes intersects with disease in the nasal cavity. When searching for the cause of ocular problems on MRI, it is important not only to examine the orbits and brain, but also the sinuses. The SSS is a clinical entity which reminds us to occasionally look beyond our own specialty of medicine in order to find the cause of symptoms within it. Acknowledgements The authors wish to thank Mrs Connie Johnson for her assistance in acquiring references. Conflicts of interest There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. Buono LM. The silent sinus syndrome: maxillary sinus atelectasis with enophthalmos and hypoglobus. Curr Opin Ophthalmol 2004; 15:486–489. 2. Soparkar CN, Patrinely JR, Cuaycong MJ, et al. The silent sinus syndrome. A cause of spontaneous enophthalmos. Ophthalmology 1994; 101:772–778. 3. Langer PD, Patel BC, Anderson RL. Silent sinus syndrome. Ophthalmology 1994; 101:1763–1764. 4. Cobb AR, Murthy R, Cousin GC, et al. Silent sinus syndrome. Br J Oral Maxillofac Surg 2012; 50:e81–e85. 5. Baujat B, Derbez R, Rossarie R, et al. Silent sinus syndrome: a mechanical theory. Orbit 2006; 25:145–148. 6. Hourany R, Aygun N, Della Santina CC, Zinreich SJ. Silent sinus syndrome: an acquired condition. AJNR Am J Neuroradiol 2005; 26:2390–2392. 7. Ross JJ, Kersten RC. Late enophthalmos mimicking silent sinus syndrome secondary to orbital trauma. J Craniofac Surg 2005; 16:840–843. 8. Rose GE, Lund VJ. Clinical features and treatment of late enophthalmos after orbital decompression: a condition suggesting cause for idiopathic ‘imploding antrum’ (silent sinus) syndrome. Ophthalmology 2003; 110:819–826. 9. Warwar RE, Rogers DL. Exophthalmos and orbital floor thickening related to maxillary sinusitis. Ophthal Plast Reconstr Surg 2003; 19:158–159.
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Neuro-ophthalmology 10. Guillen DE, Pinargote PM, Guarderas JC. The silent sinus syndrome: protean manifestations of a rare upper respiratory disorder revisited. Clin Mol Allergy 2013; 11:5. The authors provide a case report of a patient with coughing spells as the presenting symptom of SSS, and whose CT suggested chronic rhinosinusitis. 11. Suh JD, Ramakrishnan V, Lee JY, Chiu AG. Bilateral silent sinus syndrome. Ear Nose Throat J 2012; 91:E19–E21. 12. Ferri A, Ferri T, Sesenna E. Bilateral silent sinus syndrome: case report and surgical solution. J Oral Maxillofac Surg 2012; 70:e103–e106. 13. Liss JA, Patel RD, Stefko ST. A case of bilateral silent sinus syndrome presenting with chronic ocular surface disease. Ophthal Plast Reconstr Surg 2011; 27:e158–e160. 14. Facon F, Eloy P, Brasseur P, et al. The silent sinus syndrome. Eur Arch Otorhinolaryngol 2006; 263:567–571. 15. Naik RM, Khemani S, Saleh HA. Frontal silent sinus syndrome. Otolaryngol Head Neck Surg 2013; 148:354–355. 16. McArdle B, Perry C. Ethmoid silent sinus syndrome causing inward displacement of the orbit: case report. J Laryngol Otol 2010; 124:206–208. 17. Braganza A, Khooshabeh R. Ethmoidal involvement in ‘imploding’ (silent) sinus syndrome. Ophthal Plast Reconstr Surg 2005; 21:305–307. 18. Jung D, Gray ST. Silent sinus syndrome after lateral fracture of the inferior turbinate. Otolaryngol Head Neck Surg 2012; 146:863–864. 19. Eloy JA, Jacobson AS, Elahi E, Shohet MR. Enophthalmos as a complication of rhinoplasty. Laryngoscope 2006; 116:1035–1038. 20. Hobbs CG, Saunders MW, Potts MJ. ‘Imploding antrum’ or silent sinus syndrome following naso-tracheal intubation. Br J Ophthalmol 2004; 88:974–975. 21. Hobbs CG, Saunders MW, Potts MJ. Spontaneous enophthalmos: silent sinus syndrome. J Laryngol Otol 2004; 118:310–312. 22. Montezuma SR, Gopal H, Savar A, et al. Silent sinus syndrome presenting as enophthalmos long after orbital trauma. J Neuroophthalmol 2008; 28:107– 110. 23. Saffra N, Rakhamimov A, Saint-Louis LA, Wolintz RJ. Acute diplopia as the & presenting sign of silent sinus syndrome. Ophthal Plast Reconstr Surg 2013; 29:e130–e131. The authors present the first case of acute vertical diplopia as the presenting symptom of SSS. 24. Singh KA, Barber WB 2nd, Codner MA. Silent sinus syndrome: a rare presentation after botulinum toxin injection. Aesthet Surg J 2011; 31:181–183. 25. Zhang C, Phamonvaechavan P, Christoff A, Guyton DL. Silent sinus syndrome causing cyclovertical diplopia masquerading as superior oblique paresis in the fellow eye. J AAPOS 2010; 14:450–452. 26. Stevens K, Omer S, Toocaram B, et al. The imploding antrum syndrome: an unusual cause of double vision. Pract Neurol 2010; 10:101–104. 27. Kaeser PF, Borruat FX. Acquired unilateral pseudoptosis: a presentation of silent sinus syndrome. Klin Monbl Augenheilkd 2006; 223:409–411. 28. Burroughs JR, Herna´ndez Cospı´n JR, Soparkar CN, Patrinely JR. Misdiagnosis of silent sinus syndrome. Ophthal Plast Reconstr Surg 2003; 19:449– 454. 29. Wan MK, Francis IC, Carter PR, et al. The spectrum of presentation of silent sinus syndrome. J Neuroophthalmol 2000; 20:207–212. &
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30. Toh T, Weatherhead RG. Absent upper eyelid skin crease: a sign of hypoglobus. Clin Experiment Ophthalmol 2005; 33:539–540. 31. Yip CC, McCulley TJ, Kersten RC, et al. Silent sinus syndrome as a cause of diplopia in a child. J Pediatr Ophthalmol Strabismus 2003; 40:309–311. 32. Gaudino S, Di Lella GM, Piludu F, et al. CT and MRI diagnosis of silent sinus & syndrome. Radiol Med 2013; 118:265–275. Concludes that both CT and MRI can establish a diagnosis of SSS, but CT provides a better analysis of features of SSS necessary for diagnosis and differentiation from other sinus conditions. 33. Kass ES, Salman S, Rubin PA, et al. Chronic maxillary atelectasis. Ann Otol Rhinol Laryngol 1997; 106:109–116. 34. Rose GE, Sandy C, Hallberg L, Moseley I. Clinical and radiologic characteristics of the imploding antrum, or ‘silent sinus’ syndrome. Ophthalmology 2003; 110:811–818. 35. Bossolesi P, Autelitano L, Brusati R, Castelnuovo P. The silent sinus syndrome: diagnosis and surgical treatment. Rhinology 2008; 46:308–316. 36. Jacob KJ, George S, Preethi S, Arunraj VS. A comparative study between endoscopic middle meatal antrostomy and Caldwell-Luc surgery in the treatment of chronic maxillary sinusitis. Indian J Otolaryngol Head Neck Surg 2011; 63:214–219. 37. Senior BA, Kennedy DW, Tanabodee J, et al. Long-term results of functional endoscopic sinus surgery. Laryngoscope 1998; 108:151–157. 38. Kilty SJ. Maxillary sinus atelectasis (silent sinus syndrome): treatment with & balloon sinuplasty. J Laryngol Otol 2014; 128:189–191. Balloon sinuplasty is a less invasive, alternative option to treat SSS by correcting the uncinate process position, and by enlarging the maxillary sinus ostium without drilling. 39. Yiotakis I, Papanikolaou V, Alatzidou Z, et al. Silent sinus syndrome, a case presentation. Rhinology 2005; 43:313–315. 40. Sivasubramaniam R, Sacks R, Thornton M. Silent sinus syndrome: dynamic changes in the position of the orbital floor after restoration of normal sinus pressure. J Laryngol Otol 2011; 125:1239–1243. 41. Cardesin A, Escamilla Y, Romera M, et al. Single surgical step for endoscopic & surgery and orbital reconstruction of a silent sinus syndrome. Acta Otorrinolaringol Esp 2013; 64:297–299. The authors advocate for single surgical step for endoscopic surgery and orbital reconstruction. The single-stage approach has the potential advantages of avoiding morbidities associated with a second hospital stay and second anesthesia event. 42. Thomas RD, Graham SM, Carter KD, et al. Management of the orbital floor in silent sinus syndrome. Am J Rhinol 2003; 17:97–100. 43. Behbehani R, Vacareza N, Bilyk JR, et al. Simultaneous endoscopic antrostomy and orbital reconstruction in silent sinus syndrome. Orbit 2006; 25:97– 101. 44. Annino DJ, Goguen LA. Silent sinus syndrome. Curr Opin Otolaryngol Head Neck Surg 2008; 16:22–25. 45. Dailey RA, Cohen JI. Surgical repair of the silent sinus syndrome. Ophthal Plast Reconstr Surg 1995; 11:261–268. 46. Mavrikakis I, Detorakis ET, Yiotakis I, Kandiloros D. Nonsurgical management of silent sinus syndrome with hyaluronic acid gel. Ophthal Plast Reconstr Surg 2012; 28:e6–e7.
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