Inferior orbital fissure release to access the inferolateral orbital apex

To describe release of the inferior orbital fissure (IOF) as a novel surgical technique that will improve access to the inferior and inferolateral orbital apex.

Laboratory investigation.

Human cadaver heads.

Cadaveric dissection study whereby the technique of an IOF release was performed. A swinging eyelid preseptal approach was used to enable a subperiosteal dissection to the orbital floor without obstruction from orbital fat prolapse. A plane was dissected between periorbita and Muller's muscle, the smooth muscle that overlies the entire length of the IOF. Measurements were taken in the sagittal plane from a point on the inferior orbital rim directly above the infraorbital foramen to the most posterior aspect of the orbital floor.

Fifteen orbits from 8 cadaver heads were dissected with the aid of a rigid 0-degree endoscope and microsurgical instruments. This study demonstrated that an additional 10.93 ± 2.10 mm of access to the orbital apex was gained after the release of periorbita from the IOF.

We propose that the IOF release can be adopted as an adjunctive technique to orbital surgery of the inferior and inferolateral orbital apex.