Rapid Vision Loss After Root Canal Treatment Due to Invasive Fungal Sinusitis.

We present a novel case of acute invasive fungal rhinosinusitis (AIFRS) following a maxillary molar root canal in a 69-year-old diabetic female, who subsequently developed unilateral vision loss. The patient reported a 1-week history of progressive left facial pain, trismus, and numbness following the procedure. Initial evaluation was unremarkable, but her condition rapidly deteriorated, culminating in complete vision loss in the left eye. Imaging studies revealed opacification of the left-sided sinuses and a rim-enhancing collection in the left pterygopalatine fossa. Surgical debridement confirmed mucormycosis. The therapeutic approach included systemic and retrobulbar amphotericin B administration, along with multiple sinonasal debridements. The patient's poorly controlled diabetes mellitus significantly contributed to the rapid progression of the infection. Retrobulbar amphotericin B injections were effective in managing orbital involvement, thus avoiding the need for exenteration. Early diagnosis and aggressive treatment are paramount in improving outcomes for patients with AIFRS.