title: Comparison of Goldmann applanation and dynamic contour tonometry before and after cataract surgery.
abstract: OBJECTIVE
  To validate changes in intraocular pressure (IOP) after phacoemulsification with intraocular lens (IOL) implantation without pressure-lowering surgery in previously unoperated eyes of normal and glaucoma patients.
  
  
  METHODS
  University Eye Clinic, Otto-von-Guericke-University, Magdeburg, Germany.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  The IOP in both eyes of patients was determined by Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) 1 to 2 days before and after uneventful unilateral surgery. Central corneal thickness was used to correct raw GAT readings.
  
  
  RESULTS
  Of the 50 patients having unilateral phacoemulsification, 29 had had cataract extraction in the contralateral eye. The mean baseline IOP was 17.4 ± 4.4 mm Hg (GAT) and 16.6 ± 2.9 mm Hg (DCT). Postoperatively, the GAT IOP decreased to 16.4 ± 6.5 mm Hg and the DCT IOP increased slightly to 17.1 ± 4.1 mm Hg. The mean tonometer difference (ΔIOP = GAT - DCT) amounted to ΔIOP(pre) = +0.75 ± 2.69 mm Hg in phakic eyes and ΔIOP(post) = -0.70 ± 3.76 mm Hg in pseudophakic eyes (P=.0011). Consistent results were found in pairs of phakic eyes and pseudophakic eyes (mean IOP 18.0 ± 4.8 mm Hg [GAT] and 17.0 ± 3.3 mm Hg [DCT]). In fellow eyes, the mean GAT reading was 13.4 ± 4.4 mm Hg and the mean DCT value, 14.8 ± 2.4 mm Hg. ΔIOP(phakic) was +1.04 ± 2.75 mm Hg and ΔIOP(pseudophakic) was -1.48 ± 2.78 mm Hg (P=.00000021).
  
  
  CONCLUSIONS
  The GAT IOP readings in pseudophakic eyes seemed to be falsely low. Hence, special attention in the screening, diagnosis, and management of glaucoma is necessary.
authors.affiliation: Department of Ophthalmology, Otto-von-Guericke-University Magdeburg, Germany.
authors.forename: Mitja A
authors.initials: MA
authors.lastname: Heinrich
authors.forename: Timo
authors.initials: T
authors.lastname: Eppig
authors.forename: Achim
authors.initials: A
authors.lastname: Langenbucher
authors.forename: Sven
authors.initials: S
authors.lastname: Walter
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Behrens-Baumann
authors.forename: Arne
authors.initials: A
authors.lastname: Viestenz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D011184:Postoperative Period; D057234:Preoperative Period; D011446:Prospective Studies; D019591:Pseudophakia / Q000503:physiopathology*; D014065:Tonometry, Ocular / Q000295:instrumentation*