3-Dimensional Volumetric Analysis of Relationship Between the Orbital Volume Ratio and Enophthalmos in Unoperated Blowout Fractures

Overview of tools for the measurement of the orbital volume and their applications to orbital surgery

“…A variation in size between both orbits of the same patient has been documented, which leads to the misinterpretation of the true size of the fractured orbit. 35 A difference in the OV of 8% between the normal volumes of both orbits of the same patient has been recorded 17 , 36 but, in most cases, this difference is not significant. 37…”

“…29 Yang et al found that an OVR of 106.85% led to enophthalmos of 2 mm. 35 Nevertheless, in some cases, the OVR cannot be measured reliably (e.g., bilateral orbital fractures). A variation in size between both orbits of the same patient has been documented, which leads to the misinterpretation of the true size of the fractured orbit.…”

Intact Periorbita Can Prevent Post-Traumatic Enophthalmos Following a Large Orbital Blow-Out Fracture

“…19 Studies of 3-D volumetric changes in the traumatized orbit have suggested a relationship between orbital volume changes and enophthalmos, with 0.6-0.7 mm of enophthalmos for every 1 cm 3 volume change with an orbital volume change as little as 7% necessary to create clinically significant enophthalmos. 9 –14…”

“…19 Studies of 3-D volumetric changes in the traumatized orbit have suggested a relationship between orbital volume changes and enophthalmos, with 0.6-0.7 mm of enophthalmos for every 1 cm 3 volume change with an orbital volume change as little as 7% necessary to create clinically significant enophthalmos. [9][10][11][12][13][14] These data are helpful in guiding management, but the importance of the periorbital soft tissue sling is an additional critical component. 16,17 Investigations regarding the morphology of the inferior rectus muscle, whose shape will be dictated by the integrity of the periorbital-fascial support system (ie, Lockwood's ligament), have demonstrated that rounding of the inferior rectus is associated with an increased likelihood of enophthalmos.…”

“…4 Herniation of orbital soft tissue contents into the maxillary sinus is thought to play a role in the development of enophthalmos and is potentially correlated with the size of the floor defect and orbital volume changes. [9][10][11][12][13][14][15] The role of the inferior periorbital sling in preventing enophthalmos has also been described, with the shape of the inferior rectus being an important predictor of enophthalmos. 16,17 In this report, we describe a case of a large orbital floor defect with intact periorbita and no herniation of soft tissue contents in a young male following facial trauma.…”