Blowout fracture is defined as an internal orbital fracture that does not involve the orbital rim. This type of fracture results in the loss of tissue and disruption of the structure of the orbital wall. The symptoms and signs include pain, enophthalmos, diplopia, orbital emphysema, and ecchymosis 1).
Orbital subcutaneous emphysema can be associated with optic nerve and vascular compromise, with subsequent potentially irreversible visual loss.
Healy et al. reported a 4-year-old girl who presented right orbital emphysema after posterior fossa surgery for pilocytic astrocytoma resection in the sitting position. Endoscopic third ventriculostomy (ETV) had been previously carried out for the treatment of symptomatic obstructive hydrocephalus. The hypothesis is that periorbital emphysema developed due to air passing from the intracranial to the extracranial compartment through the ETV burr hole.
Result and discussion: The emphysema resolved spontaneously without any sequelae. This is the first description of orbital emphysema after posterior fossa surgery in the sitting position 2).