Background: Multiple orbital aging models have been suggested to explain the progressive development of lower eyelid prominence. Objective data to support these theories are limited, however.
Methods: Orbital anatomy was measured with high-resolution orbital magnetic resonance imaging in the quasi-sagittal plane parallel to the long axis of the orbit passing through the globe center. The association between measurements and age was analyzed by stratifying subjects into predetermined age groups and as a continuous variable.
Results: Forty subjects (17 men and 23 women) were imaged and are reported by age group: 12 to 29 years, 30 to 54 years, and 55 to 80 years. Inferior periocular soft-tissue area anterior to the anteroposterior globe axis increased with age: 99, 103, and 131 mm2 (p = 0.008), respectively. The largest contributor to this size increase was fat expansion: 28, 31, and 43 mm2 (p = 0.009), respectively. Total orbital fat also increased with age: 335, 377, and 398 mm2, respectively (p = 0.035). The globe position relative to the inferior orbit in both the anteroposterior and the superoinferior planes remained unchanged.
Conclusions: The authors' measurements suggest that with aging there is a significant increase in anterior inferior periocular soft-tissue volume, and that fat expansion is the main contributor to this volume increase. These observations provide supporting evidence that orbital fat expansion occurs with age and is the primary age-associated contributor to lower eyelid prominence, rather than globe descent or fat repositioning caused by weakening of the orbital septum. We believe these data suggest that fat excision should be a component of treatment for lower eyelid prominence.