Relationship between the extent of fracture and the degree of enophthalmos in isolated blowout fractures of the medial orbital wall.

PURPOSE: This study investigated the relationship between the extent of fracture and enophthalmos in blowout fractures of the medial orbital wall.

PATIENTS AND METHODS: Nine patients with isolated blowout fractures of the medial orbital wall, confirmed by computed tomography scans, were evaluated. The area of fracture and the volume of herniated orbital tissue were determined from computed tomography scans using simple linear measurements. Each of the calculated values for area and volume were compared with the degree of enophthalmos to determine whether there was any significant relationship between them.

RESULTS: Enophthalmos increased proportionally as the area of fracture or the volume of herniated orbital tissue increased (P < .05). The area of fracture and the volume of herniated orbital tissue associated with 2 mm of enophthalmos were 1.9 cm2 and 0.9 mL, respectively, as calculated from the regression curve.

CONCLUSION: Enophthalmos of 2 mm or more, which is a frequent indication for surgery, can be expected when the area of fracture is 1.9 cm2 or more, or the volume of herniated orbital tissue is 0.9 mL or more.