title: Intraocular pressure measured by dynamic contour tonometer and ocular response analyzer in normal tension glaucoma.
abstract: BACKGROUND
  To investigate intraocular pressure (IOP) measurement values in normal tension glaucoma (NTG) eyes using two different types of tonometer that are supposed to be little affected by corneal biochemical properties.
  
  
  METHODS
  This study included 30 normal eyes of 16 healthy subjects and 30 eyes of 16 patients with NTG. IOP was measured with a Goldmann applanation tonometer (GAT), a Pascal dynamic contour tonometer (DCT), and a Reichert ocular response analyzer (ORA) three times each for normal and NTG eyes. The main measures were GAT-IOP, DCT-IOP, corneal-compensated IOP (IOPcc), Goldmann-correlated IOP (IOPg), and central corneal thickness (CCT).
  
  
  RESULTS
  In normal eyes, GAT-IOP was 13.2 +/- 1.4 mmHg; DCT-IOP, 13.0 +/- 1.6 mmHg; IOPcc, 13.6 +/- 2.0 mmHg; and IOPg, 12.4 +/- 2.0 mmHg. Multivariate analysis revealed no significant differences between the four measurements (p = 0.08). CCT was 524.6 +/- 27.3 microns. In NTG eyes, GAT-IOP was 13.1 +/- 1.3 mmHg; DCT-IOP, 13.7 +/- 1.3 mmHg; IOPcc, 15.2 +/- 2.0 mmHg; and IOPg, 12.7 +/- 2.0 mmHg. Multivariate analysis showed significant differences between the four measurements (p < 0.01). Sheffé's test showed that IOPcc was significantly higher than GAT-IOP, DCT-IOP, and IOPg (GAT-IOP vs IOPcc: p < 0.0001; DCT-IOP vs IOPcc: p = 0.01; IOPcc vs IOPg: p < 0.0001). CCT was 515.4 +/- 32.9 microns, with no significant difference between normal and NTG eyes (p = 0.15).
  
  
  CONCLUSIONS
  We investigated the values of IOP in NTG eyes as measured by the DCT and ORA. IOPcc was significantly greater than GAT-IOP, DCT-IOP and IOPg in NTG eyes, suggesting the possibility that IOP values may be underestimated.
authors.affiliation: Department of Ophthalmology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan. tamorin@dj.mbn.or.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Morita
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shoji
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kamiya
authors.forename: Mana
authors.initials: M
authors.lastname: Hagishima
authors.forename: Fusako
authors.initials: F
authors.lastname: Fujimura
authors.forename: Kimiya
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D000368:Aged; D003315:Cornea / Q000503:physiopathology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D014065:Tonometry, Ocular / Q000295:instrumentation* / Q000379:methods
references.citation: Curr Opin Ophthalmol. 2004 Apr;15(2):102-6
references.pmid: 15021220
references.citation: Invest Ophthalmol Vis Sci. 2004 Sep;45(9):3118-21
references.pmid: 15326129
references.citation: Curr Eye Res. 2006 Oct;31(10):851-62
references.pmid: 17050277
references.citation: Invest Ophthalmol Vis Sci. 2008 Mar;49(3):968-74
references.pmid: 18326720
references.citation: Klin Monbl Augenheilkd. 2008 May;225(5):357-60
references.pmid: 18454372
references.citation: Arch Ophthalmol. 2005 Nov;123(11):1532-7
references.pmid: 16286615
references.citation: J Glaucoma. 2006 Feb;15(1):2-6
references.pmid: 16378009
references.citation: Clin Exp Ophthalmol. 2008 Aug;36(6):508-13
references.pmid: 18954311
references.citation: J Cataract Refract Surg. 2005 Jan;31(1):156-62
references.pmid: 15721708
references.citation: J Glaucoma. 2006 Oct;15(5):364-70
references.pmid: 16988597
references.citation: Jpn J Ophthalmol. 2000 Nov-Dec;44(6):643-7
references.pmid: 11094181
references.citation: Am J Ophthalmol. 1997 Jun;123(6):767-72
references.pmid: 9535620
references.citation: Am J Ophthalmol. 1998 Oct;126(4):487-97
references.pmid: 9780093
references.citation: Acta Ophthalmol (Copenh). 1975 Mar;53(1):34-43
references.pmid: 1172910
references.citation: Optom Vis Sci. 2008 Jun;85(6):463-70
references.pmid: 18521025
references.citation: Ophthalmology. 2004 Sep;111(9):1641-8
references.pmid: 15350316
references.citation: J Glaucoma. 2008 Aug;17(5):361-5
references.pmid: 18703945
references.citation: Am J Ophthalmol. 1998 Aug;126(2):326-8
references.pmid: 9727538
references.citation: Arch Ophthalmol. 1999 Jan;117(1):14-6
references.pmid: 9930155
references.citation: Ophthalmology. 2005 Aug;112(8):1327-36
references.pmid: 15964631
references.citation: J Glaucoma. 2005 Aug;14(4):288-92
references.pmid: 15990609