Pattern of anesthetic diffusion during peribulbar infiltration: a CT evaluation

The aim of this study was to evaluate the changes undergone by orbital structures during peribulbar anesthesia.

CT-thin slices were acquired and 8-9 ml of anesthetic, with a small part of low-density non-ionic water-soluble contrast medium were injected under CT guide once to follow extraconal spreading and diffusion to intraconal structures and above all, the surgically important structures such as recti muscles, orbicular and optic nerve sheath. Conjunctival sack involvement was assessed and conjunctival chemosis was rated. Induced ptosis was evaluated, verifying change before and after eyepressure.

The results help in optimizing anesthetic technique, above all concerning the site, materials and quantity, and suggest the amount of anesthesia could be reduced.

The peribulbar anesthetic technique proved effective and safe for patients.