Secondary central retinal artery occlusion due to rhino-orbital-cerebral mucormycosis in a diabetic patient: a case report.

INTRODUCTION AND IMPORTANCE: Acute sinusitis can cause intraorbital complications. Although subperiosteal abscesses generally do not cause severe vision loss, rare cases of decreased vision due to central artery or vein occlusion have been reported since 2003. Central retinal artery occlusion (CRAO) is an eye emergency that can cause sudden loss of vision. This condition is commonly found in elderly individuals with other metabolic diseases. The authors report a case of a type 2 diabetes mellitus (T2DM) patient with CRAO due to suspected rhino-orbital-cerebral mucormycosis (ROCM).

CASE PRESENTATION: A 47-year-old man came with sudden blurred vision since the last week. Examination of the left eye revealed no light perception and vision, orthophoric eyeball position with restricted movement in all directions. Hypaesthesia was observed on the left side of the face. In the anterior segment, oedema of the eyelids, ptosis, conjunctival injection, ciliary injection and chemosis, clear cornea, deep anterior chamber with VH4, brown iris, crypts, no neovascularization of the iris, pupil round, mid-dilated with a diameter of 5 mm, no light reflex, relative afferent papillary defect, and NO2NC2 lens were observed. In the posterior segment, non-uniform fundal reflexes were found, as well as retinal oedema, round papillae, hyperaemic fovea reflex (cherry-red spot), and a cup-to-disc ratio that could not be evaluated. The patient was diagnosed with CRAO, orbital cellulitis, and uncontrolled T2DM. The patient was administered topical and oral antibiotics; however, there was no improvement in the left eye. ROCM was suspected.

CLINICAL DISCUSSION: CRAO is most often caused by embolization or thrombosis associated with atherosclerosis at the lamina cribrosa level. CRAO accompanied by ROCM infection is very rare; to establish the diagnosis, it is necessary to carry out further examinations so that administered therapy can definitely improve the patient's clinical condition. Due to resource limitation, biopsy and MRI were not performed. Surgical debridement was planned when the patient was stable, but the patient missed follow-up appointments.

CONCLUSION: Fungal aetiology should be considered especially in T2DM patient with CRAO that do not improve with antibiotics.