For the purposes of this video, we need to be aware of a number of anatomical landmarks in the periorbital region. These include the medial and lateral canthus, the medial and lateral limbus, and the midpupillary line. This is because they are often used as reference points. Within the upper periorbital region, we have the following areas of interest. First, the eyebrow, then the two key muscles, the orbicularis oculi and the levator palpabrae superioris. The orbicularis oculi originates from the frontal bone, the medial palpebral ligament, and lacrimal bone, and it then inserts into the lateral palpebral raphe. This muscle contains different sections, which include the orbital, pre-tarsal, and pre-septal muscles. Contraction of the orbicularis oculi causes the eyelids to close. The levator palpabrae superioris arises from the sphenoid bone and inserts into the upper eyelid tarsal plate. When it contracts, it both retracts and elevates the eyelid. Finally, we should be aware of the retro-orbicularis oculi fat, also known as the ROOF. This is a deep fat pad beneath the eyebrow.
Now we move on to the lower periorbital region. Within this region, we find the suborbicularis oculi fat, which is also known as the SOOF. We then have the orbicularis oculi muscle, and there is also the ligaments, such as the orbicularis retaining ligament and the zygomatic retaining ligament. Other structures in this region include the infraorbital fat, the orbital septum, and various blood vessels. Finally, we have some superficial subcutaneous fat. Within the periorbital region, our focus is commonly on the treatment of the tear trough. This is a groove from the medial canthus down to the midpupillary line. It continues laterally as the lid-cheek junction, and medially and inferiorly as the mid cheek groove. It is believed that the tear trough develops because of deflation caused by a loss of volume of the underlying fat in this region, or due to differences in the pretarsal eyelid skin compared to the cheek skin. It is likely that these factors exist to form the tear trough.
We can treat the tear trough with dermal filler. Our ‘danger zone’ is the infraorbital foramen, which is located in line with the medial limbus and approximately 1 cm inferior to the orbital rim. We can see from the image that the infraorbital blood vessels pass through this region, alongside other blood vessels, and accordingly we should use a cannula in this region. The orbicularis retaining ligament is closely adhered to the bone medially and becomes looser as we move laterally. Accordingly, when we inject filler for the tear trough we can inject under the orbicularis oculi at the base of the tear trough, but need to be more superficial in the medial most aspect.