title: Decrease in intraocular pressure after orbital decompression for thyroid orbitopathy.
abstract: BACKGROUND
  The effect of thyroid orbitopathy on intraocular pressure (IOP) remains controversial. We carried out a study to determine the effect of orbital decompression surgery on the IOP in patients with advanced thyroid orbitopathy.
  
  
  METHODS
  The records of 12 consecutive patients (22 eyes) who underwent decompression surgery for severe thyroid orbitopathy between 1985 and 1996 were reviewed. All patients were maintained on essentially the same medications before and after surgery. The IOP readings, obtained by means of applanation tonometry in primary gaze, from the pre- and postoperative visits were recorded, and the net change was calculated.
  
  
  RESULTS
  The mean preoperative and postoperative IOP values were 19.8 mm Hg and 16.8 mm Hg respectively, a significant difference (p = 0.008). Seven of eight eyes with an IOP of 21 mm Hg or greater preoperatively had a postoperative IOP less than 21 mm Hg; these eyes showed a mean decrease in IOP of 5.6 mm Hg. The degree of preoperative IOP elevation was found to be a strong predictor of the amount of IOP lowering after surgery (p = 0.014).
  
  
  CONCLUSIONS
  Our results support the concept that orbital congestion associated with thyroid orbitopathy produces an increase in IOP by elevation of episcleral venous pressure (EVP) and that orbital decompression may reduce the IOP by decreasing EVP. Decompression surgery may obviate the need for more aggressive management of glaucoma in patients with severe thyroid orbitopathy.
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA.
authors.forename: S
authors.initials: S
authors.lastname: Dev
authors.forename: K F
authors.initials: KF
authors.lastname: Damji
authors.forename: C M
authors.initials: CM
authors.lastname: DeBacker
authors.forename: T A
authors.initials: TA
authors.lastname: Cox
authors.forename: J J
authors.initials: JJ
authors.lastname: Dutton
authors.forename: R R
authors.initials: RR
authors.lastname: Allingham
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical; D005260:Female; D005500:Follow-Up Studies; D006111:Graves Disease / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000209:etiology / Q000503:physiopathology; D013508:Ophthalmologic Surgical Procedures / Q000379:methods; D011379:Prognosis; D012189:Retrospective Studies