title: Change in choroidal thickness and axial length with change in intraocular pressure after trabeculectomy.
abstract: OBJECTIVE
  We studied the change in choroidal thickness (CT) and axial length (AL) after intraocular (IOP) changes produced by trabeculectomy.
  
  
  METHODS
  Twenty-one eyes of 20 patients were studied preoperatively, and then postoperatively at 1 week, 1, 3, and 6 months. Variables measured included IOP, AL, keratometry, refractive error, central corneal thickness, and average CT in the posterior 6 mm centred on the fovea using enhanced depth imaging spectral domain optical coherence tomography (OCT).
  
  
  RESULTS
  OCT images in 17 eyes (58 images, preoperatively and postoperatively) were of sufficient quality to determine CT. In every patient, CT increased with IOP lowering postoperatively. For each 1 mmHg decrease in IOP, there was a mean increase of 3.4 µm in CT (p<0.0001; univariate regression, 95% CI 2.5 to 4.3). This represented a CT increase of 1.7% per mm Hg decrease (p<0.0001; 95% CI 1.3 to 2.0%). AL decreased by 6.8 µm per mm Hg decrease in IOP (p<0.0001, univariate regression, 95% CI 4.9 to 8.6).
  
  
  CONCLUSIONS
  The dynamic relationship between change in IOP and the state of sclera and choroid was confirmed by sequential measurements in postoperative trabeculectomy patients, providing estimates of the magnitude of choroidal swelling and scleral volume decrease with IOP lowering.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: Osamah
authors.initials: O
authors.lastname: Saeedi
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: Angelique
authors.initials: A
authors.lastname: Pillar
authors.affiliation: Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Joan
authors.initials: J
authors.lastname: Jefferys
authors.affiliation: Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Karun
authors.initials: K
authors.lastname: Arora
authors.affiliation: Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: David
authors.initials: D
authors.lastname: Friedman
authors.affiliation: Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Harry
authors.initials: H
authors.lastname: Quigley
mesh_terms: D000368:Aged; D058452:Axial Length, Eye / Q000473:pathology*; D002829:Choroid / Q000473:pathology*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000503:physiopathology / Q000601:surgery*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014130:Trabeculectomy
keywords: Choroid; Glaucoma; Imaging; Intraocular pressure