title: Prognostic CT findings of diplopia after surgical repair of pure orbital blowout fracture.
abstract: OBJECTIVE
  Diplopia is a common sequela of blowout fracture even after proper surgical management. We investigated the prognostic factors of diplopia after surgery of pure blowout fracture.
  
  
  METHODS
  We retrospectively reviewed CT images of 181 patients with pure orbital blowout fracture who underwent at least six months of postoperative follow-up. We evaluated the following CT factors: (1) fracture site (orbital floor, medial wall of the orbit, or both), (2) fracture type (closed flap, open flap), (3) fracture size, (4) volume of herniated orbital soft tissue, (5) ratio of volume of herniated orbital soft tissue to fracture size, (6) number of points of contact between extraocular muscle (EOM) and bony edge, (7) presence of EOM thickening, (8) EOM swelling ratio, (9) presence of displacement of EOM, (10) presence of deformity of EOM, (11) presence of tenting of EOM, and (12) presence of entrapment of EOM. The associations between diplopia at six months after surgical repair and various risk factors were analyzed using logistic regression models for univariable and multivariable analyses.
  
  
  RESULTS
  EOM tenting and deformity and ratio of volume of herniated orbital soft tissue to fracture size were found to be statistically significant risk factors of diplopia at six months after repair on univariable analysis (all P < 0.05). Patients who showed EOM tenting or deformity on CT images had 5.22 and 10.85 times greater probability of diplopia after surgery, respectively (P-value, <0.001 and 0.026; 95% confidence interval of odds ratio, 2.071-13.174 and 1.323-88.915, respectively). On the other hand, ratio of volume of herniated orbital soft tissue to fracture size was not significant on multivariable analysis (P = 0.472).
  
  
  CONCLUSIONS
  The prognosis of patients was predicted by CT evaluation. Patients who have tenting or deformity of EOM on CT scan are more likely to have postoperative diplopia.
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Hyena
authors.initials: H
authors.lastname: Jung
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 06591, Republic of Korea. Electronic address: jybyun@catholic.ac.kr.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Byun
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Hyung-Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Min
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Gyeong Min
authors.initials: GM
authors.lastname: Park
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Ha Youn
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Yi Kyung
authors.initials: YK
authors.lastname: Kim
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Jihoon
authors.initials: J
authors.lastname: Cha
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea.
authors.forename: Sung Tae
authors.initials: ST
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004172:Diplopia / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009917:Orbital Fractures / Q000000981:diagnostic imaging* / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Blowout fracture; Computed tomography; Diplopia; Extraocular muscle; Prognosis; Surgical repair