Anatomic and physiologic approach for trans-conjunctival needle decompression of orbital emphysema.

A 19-year-old with blunt trauma and repeated nose blowing presented with orbital emphysema and orbital compartment syndrome. Orbital emphysema is the abnormal presence of air within the orbit, typically secondary to trauma. Most cases will resolve with observation alone, however orbital compartment syndrome is a feared complication that necessitates urgent decompression. A superior fornix, trans-conjunctival approach was safely utilized to decompress the orbit while avoiding unwanted complications. Various decompression techniques have previously been described, most of which describe trans-palpebral approaches. The key safety benefit to the trans-conjunctival approach is direct visualization of the needle tip adjacent to the superior fornix, therefore posterior to the equator of the globe. With the needle positioned parallel to the curvature of the globe at the equator, the posterior sclera surface curves away from the tip, rendering it difficult to pierce the globe. In addition, the needle needs to be advanced only 3-4 millimeters and traverses only the conjunctiva and Tenon's to enter the central surgical space - the most direct route to the air pocket. The trans-conjunctival approach lowers the risk of damage to eyelid neurovascular structures and is less painful.