Prediction of Late Enophthalmos by Volumetric Analysis of Blowout Fractures using Orbital CT

Baek, Sae Heun; Lee, Tae Soo

Abstract

The purpose of this study was to determine whether orbital volume assessment by CT could provide additional information for the initial evaluation of orbital blowout fractures and guide optimal treatment. The medical records of 26 patients with orbital blowout fractures, either surgically or conservatively managed, were retrospectively reviewed. Orbital volumetric analysis was then determined from digitized CT scans. Fracture-related volume expansion relative to the unaffected fellow orbit was correlated with degree of enophthalmos. Early Hertel's measurements[<4 weeks] were available in 21 patients and did not correlate with the volumetric values or with subsequent late enophthalmos. Late Hertel's measurements[>4 weeks] were obtained in 13 nonrepaired fractures and in 3 of 13 surgically repaired patients[late presentation;16 patients]. When seen at more than 4 weeks, 4[80%] of 5 patients with> OR =13% orbital volume expansion manifested significant enophthalmos[>2 mm] compared with 2[18.2%] of 11 patients with<13% orbital expansion[p<0.01]. CT measurements of orbital volume can predict the final degree of late enophthalmos and may facilitate the planning of surgical intervention.