|Year : 2019 | Volume
| Issue : 3 | Page : 225-227
Allergic fungal sinusitis presenting as optic neuritis: A diagnostic dilemma
R Neena1, Mathew Dominic2
1 Department of Paediatric Ophthalmology, Strabismus and Neuro-Ophthalmology Services, Giridhar Eye Institute, Kadavanthara, Kochi, Kerala, India
2 Department of Ear Nose Throat, Medical Trust Hospital, Kochi, Kerala, India
|Date of Web Publication||31-Dec-2019|
Dr. R Neena
Department of Paediatric Ophthalmology, Strabismus and Neuro-ophthalmology Services, Giridhar Eye Institute, Kochi - 682 020, Kerala
Source of Support: None, Conflict of Interest: None
Aim: To familiarize ophthalmologists with the rare but potentially vision-threatening complication of optic neuritis from allergic fungal sinusitis.
This is a case report of a healthy young female who presented with rapidly deteriorating vision and clinical features of acute optic neuritis of the left eye. Computerized tomography of the brain and orbits revealed an invasive bilateral sphenoid sinus mass with encasement of the left optic nerve, bone erosion, and intracranial extension. Ear, nose, and throat examination revealed nasal polyposis with sinusitis. Endoscopic biopsy revealed extensive allergic fungal debris filling sinuses and eroding the medial end of the optic canal on left side suggestive of allergic fungal sinusitis. An emergency functional endoscopic sinus surgery and optic nerve decompression followed by systemic steroid therapy restored her vision. The culture of the nasal biopsy grew Aspergillus fumigatus.
Keywords: Allergic fungal sinusitis, best corrected visual acuity, computerized tomography, functional endoscopic sinus surgery, magnetic resonance imaging, optic neuritis, relative afferent pupillary defect
|How to cite this article:|
Neena R, Dominic M. Allergic fungal sinusitis presenting as optic neuritis: A diagnostic dilemma. Kerala J Ophthalmol 2019;31:225-7
| Introduction|| |
Allergic fungal sinusitis (AFS),, is a highly recurrent, noninvasive infection, causing 5%–10% of chronic fungal rhinosinusitis. It typically occurs in patients with a history of atopy, rhinitis, or chronic sinusitis. Ophthalmic manifestations in AFS have been reported to be close to 18%, commonly orbital., Optic neuropathy causing visual loss is rare.
| Materials and Methods|| |
This is a retrospective case report of an otherwise healthy 26-year-old female who presented with clinical features of sudden onset of blurred vision in left eye of 1-week duration, consistent with acute optic neuritis of the left eye. Her best-corrected visual acuity (BCVA) in OD was 6/6; N6 and in OS 6/18p; N18 respectively. Color vision was reduced in the left eye with a Grade II Relative Afferent Pupillary Defect (RAPD). She was orthophoric with normal anterior segment and ocular motility. Dilated evaluation revealed a normal fundus in the right eye, but a hyperemic, edematous optic disc with dull foveal reflex of the left eye [Figure 1]a. Intraocular pressures were within normal limits in both eyes. Visual field evaluation was normal in the right eye, but showed a dense near-total defect in the left eye [Figure 1]b. She had no systemic risk factors. Her vital signs and blood investigations were normal. Suspecting acute optic neuritis in the left eye, she was advised for magnetic resonance imaging (MRI) of the brain and orbits before starting on intravenous (IV) steroid therapy. As she had dental braces, MRI was deferred and computerized tomography (CT) of the brain and orbits was done, which revealed an invasive mass in bilateral sphenoid sinuses, extending to frontal and ethmoidal sinuses, eroding clivus, and further extending intracranially with 360° encasement of the left optic nerve and 90° abutment of the right optic nerve [Figure 2]a. Her BCVA of the left eye had dropped to CF 2 m by then. She was urgently referred to the ear, nose, and throat (ENT) surgeon for an endoscopic biopsy to rule out infective and malignant causes. ENT examination revealed nasal polyposis with sinusitis. An emergency functional endoscopic sinus surgery, endoscopic biopsy, and optic nerve decompression were done. Intraoperatively, there was extensive allergic fungal debris filling sinuses and eroding the medial end of the optic canal on the left side [Figure 2]b. Intravenous IV 1 g methylprednisolone injections were given postoperatively for 5 days followed by tapering the dose of oral steroids for 2 weeks.
|Figure 2: (a) Computerized tomography of the brain and orbits. (b) Intraoperative picture|
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| Results|| |
Endoscopic biopsy revealed polypoid fragments of inflamed sinonasal mucosa with a dense mixed inflammatory infiltrate of lymphoplasma cells, neutrophils, and eosinophils in a lake of brightly eosinophilic allergic mucin with sheets of degenerating eosinophils with no fungal tissue invasion of the mucosa [Figure 3]a, suggestive of allergic fungal debris and polyp confirming the diagnosis of AFS. Culture of biopsy specimen grew Aspergillus fumigatus [Figure 3]b. Posttreatment, BCVA in the left eye improved to 6/6; N6 with complete resolution of RAPD, color vision, and visual field defects and disc edema – [Figure 4]a, [Figure 4]b, and [Figure 5]a, respectively.
|Figure 3: (a) A dense mixed inflammatory infiltrate of lymphoplasma cells, neutrophils, and eosinophils in a lake of brightly eosinophilic allergic mucin with sheets of degenerating eosinophils with no fungal tissue invasion of the mucosa. (b) Culture of biopsy specimen grew Aspergillus fumigatus|
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|Figure 5: (a) Optical coherence tomography-retinal nerve fiber layer: pretreatment and posttreatment. (b) Compare and contrast allergic fungal sinusitis and invasive fungal sinusitis|
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| Discussion|| |
AFS is an allergic hypersensitivity reaction to inhaled fungal elements. It can mimic other fungal rhinosinusitis, especially invasive fungal sinusitis (IFS). The diagnostic dilemma was, as our patient was free of all systemic symptoms, immunocompetent, with no signs of sinusitis, with rapidly deteriorating vision due to optic neuritis. A high index of suspicion, immediate imaging, and prompt biopsy clinched the diagnosis and timely management saved the vision. Although fungal elements are seen in AFS, the noninvasion of the sinus mucosa distinguishes it from the more deadly IFS, the treatment of which is very different [Figure 5]b.
Diagnostic criteria of AFS :
- Serological evidence of Type 1 hypersensitivity
- Nasal polyposis
- hyperattenuated sinus contents with bone erosion
- Eosinophilic mucin without fungal tissue invasion
- Positive fungal stain.
| Conclusion|| |
Although AFS is a common cause of chronic rhinosinusitis, optic neuropathy causing visual loss is rare. This report highlights the timely detection of AFS in a young patient with no prior history of sinusitis, its prompt management, and complete resolution and recovery with appropriate treatment. This report also aims to emphasize the important role of imaging in localizing lesions and even more crucial role of tissue biopsy in diagnosing and managing puzzling neuroophthalmic conditions.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]