Histopathological evidence of central retinal artery occlusion secondary to angio-invasive fungal infection amidst SARS-CoV-2 pandemic.

Abstract

Rhino-orbital-cerebral mucormycosis (ROCM) can present in various forms, the most common being ophthalmoplegia, with or without central retinal artery occlusion (CRAO).[123] Patients with minimal to no evidence of orbital involvement by fungus on imaging also develop restrictions of ocular movement in all gazes. Lesions causing ophthalmoplegia usually involve the orbital apex and/or the cavernous sinus. Mucor has a tendency for angioinvasion leading to thrombosis of blood vessels and resultant tissue necrosis.[4] A 64-year-old diabetic gentleman presented to us with loss of vision, absent ocular motility, and ptosis in the right eye after having recovered from COVID-19 infection 3 weeks prior [Fig. 1a]. He was noted to have CRAO in the right eye [Fig. 1b]. He was subsequently diagnosed with ROCM and underwent right orbital exenteration due to worsening. Despite minimal cellulitis secondary to orbital apex involvement, the muscular arteries were invaded by fungus with aseptate hyphae (as noted on histopathological examination), leading to ophthalmoplegia and ptosis. Histopathological (HPE) analysis of the right optic nerve stump of the exenterated specimen in our patient with ophthalmoplegia and CRAO revealed occlusion of the central retinal artery secondary to invasion of its muscular coat by a fungus with aseptate hyphae [Fig. 1c and d]. Endothelial cell damage and activation of coagulation cascade is the key pathophysiological mechanism for thrombus formation.[45]Figure 1: (a) Clinical picture of a patient with right-eye complete ophthalmoplegia with ptosis. (b) Fundus photograph highlighting right-eye central retinal artery occlusion leading to vision loss. (c) Optic nerve (black asterisk) and central retinal artery (black arrow) invaded by fungal hyphae leading to arterial occlusion (low power). (d) Periodic acid–Schiff staining showing the section of the central retinal artery with vascular invasion (black arrowheads) with broad aseptate hyphae highlighted (high power)To the best of our knowledge, this is the first reported direct histopathological evidence of angioinvasion of the central retinal artery by Mucorales species leading to vision loss in a case of ROCM. 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 Nil. Conflicts of interest There are no conflicts of interest.