Purpose:
To describe the location of the zygomatico-orbital foramen on the inferolateral orbital wall and its potential implications during orbital surgery and peribulbar injections.
Methods:
This study was performed on 14 dry adult human skulls (28 sides) obtained from the Anatomy Laboratory of New York University School of Medicine. The zygomatico-orbital foramen was identified by passing a thin wire from the zygomatico-facial foramen (on the malar surface of the zygomatic bone) to its orbital aspect (see image). A thin flexible ruler was used to measure: 1) the distance perpendicular to the closest point on the inferior orbital rim, 2) the distance from the inferior orbital fissure and 3) the distance from the area used for retrobulbar injections (defined as the point between the lateral one-third and medial two-thirds of the inferior orbital rim). This last measurement was taken on each skull by measuring the widest distance of the orbital rim and dividing the inferior portion into thirds.
Results:
The zygomatico-orbital foramen was identifiable on 22 of the 28 orbits examined; 10 right and 12 left orbits. On 6 orbits, the foramen could not be identified. The mean distance from the closest point on the inferior orbital rim was 4.7 mm (range from 1.0 to 7.0 mm). The mean distance from the inferior orbital fissure was 14.9 mm (range from 10.0 to 18.0 mm). The mean distance from the area of retrobulbar injection was 6.0 mm (range from 3.0 to 10.0 mm).
Conclusions:
The location of the zygomatico-orbital foramen within the orbit is quite variable. Its contents, which include the artery and nerves, lie in close proximity to the site of retrobulbar injections, especially considering the variability in technique among ophthalmologists when giving such injections. It is also important to avoid injuring the artery when elevating periorbita from the lateral wall during orbital surgery, as rupture of this vessel may cause retrobulbar hemorrhages.