Teaching Case

A 58-year-old male patient was referred to our department with acute worsening vision in both eyes. He had a history of disseminated plasmacytoma in remission. Ophthalmologic examination was remarkable for BCVA (best corrected visual acuity) of no light perception, positive relative afferent pupillary defect (RAPD) and retinal thinning in the right eye. Left eye presented with BCVA of hand motion and an ill-defined temporal perimacular yellow-coloured retinal lesion.

Non-contrast computer tomography (CT) of the head shows mucosal thickening of the right sphenoid sinus and individual ethmoidal air cells of the right side. The rest of the paranasal sinuses are well-aerated and clear. CT images demonstrated no other intracranial abnormalities (Figure 1).

Magnetic resonance imaging (MRI) of the brain additionally demonstrated intense mucosal enhancement of the right sphenoid sinus (Figure 2) and dural thickening of planum sphenoidale with a prominent enhancement of planum sphenoidale (Figure 3) and both optic canals. Mild enhancement and focal FLAIR/T2 hyperintense signal of the left optic nerve were seen as well (Figure 4). No pathologic changes were seen in the brain parenchyma or the ventricular system. 

MRI of the brain two months later showed a progression of the disease with marked enhancement and dural thickening of the planum sphenoidale, above sella turcica and cavernous sinus (Figure 5). Bilateral optic nerve enhancement was more prominent than previously.

Case progression

Upon initial examination, the patient’s loss of vision was presumed due to temporal arteritis, and he was treated with a dose of methylprednisolone. In the following days, he developed a fever, and invasive fungal sepsis was confirmed. Further investigation revealed a central retinal artery occlusion of the right eye and Aspergillus endophthalmitis of the left eye. Intraocular and systemic antifungal treatment resulted in sepsis resolution, with no improvement in BCVA upon follow-up.

Background 

Localised mycotic sinusitis is mainly caused by organisms from either Aspergillus species or Zygomycetes order. The most commonly affected sites include maxillary and ethmoid sinuses. Patients may initially present with mild, nonspecific symptoms. Upon progression to acute invasive fungal rhinosinusitis (AIFR), the disease can complicate with life-threatening orbitocranial extension[1]. 

Risk factors for disease advancement to AIFR include insulin-dependent diabetes and forms of immunosuppression; prolonged or severe neutropenia, history of immunosuppressive therapy and haematological malignancy[2,3].

Clinical Perspective 

AIFR with ocular advancement may present with a variety of quickly onset ophthalmic signs, including proptosis, chemosis, diplopia and ophthalmoplegia. Compression of the optic nerve or occlusion of the central retinal artery produce acute irreversible vision loss[4]. In rare cases, haematologic dissemination of fungal pathogens produces severe endogenous endophthalmitis with vitritis and retinal necrosis[5].

The gold diagnostic standard is microbiological identification from samples of sinus mucosa and, in cases of endophthalmitis, samples of pars plana vitrectomy[6]. However, imaging is crucial to determine the degree of sinus involvement and helps distinguish non-invasive sinusitis from invasive disease[7].

Imaging Perspective

CT of the paranasal sinuses demonstrates mucosal thickening and opacification of the sinuses. Areas of hyperattenuation are frequently observed within the opacified sinuses, most frequently affected being maxillary and ethmoid sinuses. CT is especially useful for detecting bone destruction. Fat stranding of the surrounding adipose tissue may be seen, particularly in the intraorbital fat. Particularly in the early stages of the disease, imaging findings may be mild and non-specific.

MRI is the modality of choice for evaluation of soft tissue invasion. Mucosal thickening or opacification of the sinuses is usually T1- and T2- hypointensive or isointensive. Necrosis of affected mucosa is typically demonstrated with a lack of normal enhancement. Pathological signs of invasion beyond sinuses include intraorbital, intracranial and vascular invasion. Stranding of the periantral fat, leptomeningeal enhancement and intracranial granulomas may be seen. Severe acute invasive fungal sinusitis complications include epidural abscess, venous sinus thrombosis, mycotic aneurysm formation and cerebral infarction or haemorrhage [8,9]. 

To determine ocular involvement, a fundoscopy with optical coherence tomography may be used, however, in cases of dense vitritis, the posterior pole is visualised using B-scan ultrasonography[10].

Outcome

Treatment consists of a combination of surgical and medical approaches. Endoscopic surgical debridement of necrotic mucosal tissue lessens the pathogen burden and slows disease progression[11,12].

Medical therapy is initiated with intravenous or oral voriconazole in combination with intravitreal application of antifungal medication (voriconazole or amphotericin B). In cases of severe vitritis, early complete pars plana vitrectomy significantly reduces the risk of complications, including retinal detachment[10].

Despite the available therapeutic options, systemic tissue-invasive and angioinvasive fungal disease with ophthalmic involvement has a significant mortality rate in immunocompromised patients, with mortality ranging from 21% to 80%[13].

Take Home Message / Teaching Points

In immunocompromised patients, fungal sinusitis may complicate with localised and systemic invasion and requires a multidisciplinary treatment approach.