Comparison of Orbital Volume in Young Versus Senescent Human Skulls

PURPOSE To compare bony orbital volumes in young skulls with those of older skulls to elucidate aging-associated changes of the orbit. METHODS One hundred Caucasian male skulls from the Hamann-Todd collection of the Cleveland Museum of Natural History were studied. There were 50 young skulls (age range, 19-33 years) and 50 senescent skulls (age range, 79-96 years). Volcanic sand was used to fill each orbit in an identical fashion and weighed as a proxy for volume. Digital calipers were used to perform linear measurements of the orbit. The relationship between orbit measures and skull size was assessed using Pearson's correlations and 95% CI, and statistical models to compare age groups adjusted for skull size. RESULTS The volume of the orbits (P < 0.001), the horizontal diameter of the orbit (P = 0.015), and the orbital depth (P < 0.001) were significantly larger in the senescent group of skulls after adjusting for skull surface area. No significant differences were found in the vertical diameters of the orbit between the 2 groups. Skull size did not statistically differ between the age groups. CONCLUSIONS Increases in the depth and horizontal dimensions of the orbit lead to increasing bony orbital volume with increasing age. These changes in size and shape of the orbit with age may contribute to phenotypic changes of aging and may affect disease processes and management.