Pathogenesis of Non-Arteritic Anterior Ischemic Optic Neuropathy Associated with COVID-19.

Non-arteritic ischemic optic neuropathy (NAION) results from vascular insufficiency within the optic nerve head. The precise pathogenesis of NAION remains unclear; however, insufficient blood supply from the short posterior ciliary arteries and the choroidal circulation has been associated with its development. Although major risk factors include diabetes, hypertension, and hyperlipidemia, coronavirus disease 2019 (COVID-19) may also contribute to the development of NAION. This literature review presents our case of NAION associated with COVID-19 infection and summarizes previously reported cases of NAION following COVID-19 infection published in the English-language literature worldwide. Because direct infection of ocular tissues, including ocular vessels, via the angiotensin-converting enzyme 2 receptor is thought to contribute to the development of NAION, cases of NAION associated with COVID-19 vaccination were excluded from this review. Furthermore, we discuss the possible molecular mechanisms underlying the development of NAION after COVID-19 infection and highlight the potential risks of COVID-19 for clinical ophthalmologists.