Orbital necrotizing fasciitis due to Prevotella baroniae resulting in acute orbital compartment syndrome.

A 44-year-old man with uncontrolled diabetes mellitus (A1C: 9.9%), a well-established risk factor for infection, presented with acute onset of complete vision loss in the right eye (OD) associated with periorbital swelling, pain, and proptosis. Visual acuity was no light perception OD with intraocular pressure of 45 mmHg. Clinical examination revealed significant right sided proptosis and orbital inflammation. Emergent canthotomy and cantholysis were performed. He was then taken to the operating room where biopsy revealed a rapidly progressive orbital necrotizing fasciitis (ONF) involving Prevotella baroniae. Due to clinical worsening despite broad spectrum antibiotics and surgical debridement, the patient ultimately required orbital exenteration. The identification of Prevotella baroniae in the orbit is rare. This case highlights the aggressive nature of ONF and its potential for progression to orbital compartment syndrome, emphasizing the need for high clinical suspicion of these conditions. Timely surgical and medical interventions are imperative for preserving visual function and preventing mortality.