Superior and transantral orbital decompression procedures. Effects on increased intraorbital pressure and orbital dynamics.

Eight superior and eight transantral decompressions were performed in 16 fresh cadaver orbits in which intraorbital pressure was experimentally increased by adding 12 mL of volume to an intraorbital balloon. Each decompression yielded a mean pressure decrease of 225 mm Hg (85% of the total) in experimentally induced intraorbital pressure. The maximal pressure decrease occurred after the removal of the first complete orbital wall. However, incision of the periorbita was most effective in achieving globe recession and a decrease in exophthalmos. Although the steps of the superior and transantral decompression techniques are not comparable, there was no statistically significant difference between the total net pressure decreases achieved.