Infraorbital Fat Compartments and the Distended Lower Eyelid
Herniation of the infraorbital fat has been viewed as major contributing factor in lower eyelid distension. Classically, three compartments—medial, central, and lateral—have been described. Some disagreement remains, however, over whether these represent true anatomic divisions or merely clinically useful divisions. Our study looks at patterns of infraorbital fat herniation in patients presenting with lower eyelid distension in order to determine how variations in surface appearance may help inform our understanding of the underlying anatomy.
Methods/Technique:
95 patients who presented for lower lid rejuvenation were included in this study. Clinical patterns of infraorbital fat herniation were observed using standard photographic views.
A total of 10 orbits from 5 adult cadaveric specimens were analyzed. The skin and orbicularis oculi muscle were dissected to reveal the underlying anatomy of the infraorbital septum and infraorbital fat.
Results/Complications:
In the majority of patients (85%, n=162), a clear demarcation between the medial and central compartments could not be clinically observed. Bulging of the medial and central fat compartments as a single unit was the most common pattern (51%, n=97), followed by bulging of the medial and central compartments as a single unit and the lateral compartment as a second unit. Prominence of three distinct compartments was rare (1%, n=4).
In all of our cadaveric specimens, a clear demarcation between the central and lateral compartments was observed. In contrast, a definite demarcation between the medial and central fat compartments was clearly observed in only 4 specimens. In most cases fat tended to engulf the inferior oblique and move freely between the medial and central compartments with minimal dissection (n=7).
Conclusion:
We conclude that when attempting surgical rejuvenation of the lower eyelid, the demarcation between the medial and central fat compartments may not be as clinically important as the demarcation between the central and lateral fat compartments.