Transcutaneous retrobulbar injection of amphotericin B in rhino-orbital-cerebral mucormycosis: a review

Mucormycosis is an aggressive and potentially fatal invasive fungal infection. The most common form of mucormycosis is rhino-orbital-cerebral mucormycosis (ROCM). While it is commonly seen in immuno-compromised patients, it is also known to affect healthy individuals. The global disease burden of ROCM has increased significantly following the surge in cases during the COVID-19 pandemic. Endoscopic sinus debridement, systemic antifungal therapy, and control of the underlying immunosuppressive condition are essential for the management of ROCM. Orbital involvement, however, presents a challenge to clinicians. Intervention strategies that have been described to treat orbital disease include orbital exenteration, conservative orbital debridement with or without irrigation with amphotericin B and transcutaneous retrobulbar injection of amphotericin B (TRAMB). Currently, there is a lack of clarity regarding the indications and outcomes of TRAMB as a treatment modality. In this review, the drug formulations used, the complications, and outcomes of previously described cases that have used TRAMB in cases of ROCM are discussed. Favorable outcomes following TRAMB depend on appropriate patient selection and radiological evidence of the orbital burden of the disease. This review aims to familiarize clinicians with objective parameters for patient selection for TRAMB, namely the extent of the disease, the clinical features, and radiological findings; viz. the clinical interpretation of areas of contrast uptake and those of necrosis. TRAMB can be considered as a viable option in select cases of orbital mucormycosis where exenteration or debridement are not indicated, or when there is limited orbital disease.