Rhino-orbital Mucormycosis Manifesting as Orbital Apex Syndrome with CRAO in An Immunocompetent Patient

Abstract

Rhino-orbital mucormycosis (ROM) is an uncommon opportunistic infection affecting immunocompromised individuals. Poorly controlled diabetes mellitus is the commonest predisposing factor. A 42-year-old female with well controlled diabetic status, presenting with orbital apex syndrome (OAS) and Central Retinal Artery Occlusion (CRAO) is discussed in this report. There was no evidence of cellulitis, necrotic eschar or facial palsy. There were no features suggesting immunosuppression. The biochemical parameters including blood sugar and electrolytes were normal. Serology for HIV was negative. MRI showed pan sinusitis with thickening and enhancement of extraocular muscles. Urgent debridement of paranasal sinuses was done. Histopathological examination disclosed broad based, filamentous, aseptate hyphae suggestive of mucormycosis. Prompt treatment with systemic Amphotericin B and debridement of sinuses resulted in a favourable outcome. Mucormycosis presents with a constellation of clinical features including ophthalmoplegia, proptosis, ptosis, visual loss, chemosis, nasal discharge, abducens nerve palsy, palatal necrosis, cerebral involvement, hemiparesis and eye lid gangrene. The coexistence of sinus disease with OAS in a diabetic patient should trigger a vigilant search for a fungal etiology, despite the absence of immunosuppression. Microbiological culture may yield negative results and histopathological examination is mandatory. This report emphasizes the rare occurrence of ROM in an immunocompetent diabetic patient with good metabolic control. Early diagnosis and a multidisciplinary approach with intravenous antifungals, adequate sinus drainage and surgical debridement can greatly reduce the morbidity and mortality.