Infectious optic neuropathy: the interplay between pathogens and the host immune system-a review of diagnostic and therapeutic dilemmas.

Infectious optic neuropathy (ION) represents a major clinical challenge at the intersection of ophthalmology and neurology. Its pathogenesis typically involves a complex interplay between direct pathogen invasion and post-infectious immune-mediated injury. Current clinical management faces two core challenges: (1) accurately differentiating direct pathogen-induced injury from post-infectious autoimmune optic neuritis [e.g., myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)]; and (2) avoiding exacerbation or dissemination of occult infection when immunosuppressive therapy is required. Traditional static classification models based on pathogen profiles are insufficient to guide dynamic clinical decision-making and may lead to delayed treatment or overtreatment. In this review, we propose a dynamic decision-making framework grounded in pathophysiological mechanisms. We summarize practical clinical clues for distinguishing these two injury patterns, outline key considerations for systemic corticosteroid use, and discuss the positioning of emerging diagnostic technologies-such as metagenomic next-generation sequencing (mNGS)-within current clinical pathways. Drawing on available clinical evidence, we advocate an individualized intervention strategy centered on "dynamic balance," emphasizing that decisions should be guided by the predominant mechanism at each disease stage rather than a rigid dichotomy between "infectious versus non-infectious." Finally, we highlight key evidence gaps and underscore that this mechanism-informed framework is a pragmatic synthesis that requires prospective validation.