title: Hess area ratio and diplopia: evaluation of 30 patients undergoing surgical repair for orbital blow-out fracture.
abstract: OBJECTIVE
  To determine if the Hess area ratio is effective in predicting postoperative diplopia in patients undergoing surgery for orbital blow-out fracture.
  
  
  METHODS
  Our retrospective, interventional case series study involved 30 consecutive cases affected by orbital fractures and diplopia undergoing surgical correction within 7 days after injury. To evaluate ocular motility disturbance, we measured the involved ocular motility range by use of a manual Hess screen test before and 4 months after surgery. The percentage of Hess area ratio % was used to express the range of ocular motility in a numerical value.
  
  
  RESULTS
  All patients with preoperative Hess area ratio >85% had no postoperative diplopia, and most patients (57%) having a preoperative Hess area ratio <65% had postoperative diplopia. When the Hess area ratio was between 65% and 85%, surgical outcomes were variable and most patients (55%) described no problematic diplopia in the peripheral visual field.
  
  
  CONCLUSIONS
  The Hess area ratio is a useful procedure to convert Hess graphic representation in a numerical value so that Hess chart data can be compared among clinicians and used to predict surgical outcomes in patients undergoing surgery for orbital blow-out fractures.
authors.affiliation: Department of Ophthalmology, University of Rome La Sapienza, Rome, Italy. plgrenga@hotmail.it
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Grenga
authors.forename: Gabriele
authors.initials: G
authors.lastname: Reale
authors.forename: Carmela
authors.initials: C
authors.lastname: Cofone
authors.forename: Alessandro
authors.initials: A
authors.lastname: Meduri
authors.forename: Piero
authors.initials: P
authors.lastname: Ceruti
authors.forename: Roberto
authors.initials: R
authors.lastname: Grenga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004172:Diplopia / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000503:physiopathology*; D009917:Orbital Fractures / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000592:standards; D012189:Retrospective Studies; D055815:Young Adult