title: A Comparative Study of Rebound Tonometry With Tonopen and Goldmann Applanation Tonometry Following Vitreoretinal Surgery.
abstract: OBJECTIVE
  To investigate agreement in intraocular pressure (IOP) measurements among Icare rebound tonometry, Tonopen tonometry, and Goldmann applanation tonometry following vitreoretinal surgery.
  
  
  METHODS
  Reliability analysis of tonometers.
  
  
  METHODS
  Fifty-eyes of 50 adults undergoing vitreoretinal surgery were enrolled. IOP was measured on first postoperative day using Icare (Tiolat, Helsinki, Finland), followed by Tonopen (Reichert, Depew, New York, USA) and Goldmann (Haag-Streit USA, Mason, Ohio, USA) in randomized order. Intraclass correlation coefficients (ICC) and Bland-Altman plots were calculated for all subcategories.
  
  
  RESULTS
  Icare successfully measured IOP in all eyes, while Goldmann was unmeasurable in 6 eyes (12%) and Tonopen in 1 eye (2%). Mean IOP by Icare, Tonopen, and Goldmann was 15.9 ± 8.9, 16.9 ± 6.2, and 16.0 ± 7.3 mm Hg, respectively (P = .76). Type of intraocular tamponade, status of lens, status of cornea, gauge of instrumentation, and history of prior vitrectomy did not result in significant differences among the 3 tonometers. ICC was excellent (>0.75) in all subgroups, except at IOP <10 and ≥ 23 mm Hg (based on Icare). In eyes with IOP <10 mm Hg, Icare underestimated IOP (mm Hg; P = .01) compared to Goldmann (2.0 ± 2.1) and Tonopen (3.5 ± 2.4), whereas at IOP ≥ 23 mm Hg Icare was overestimated (P = .01) compared to Goldmann (3.77 ± 3.49) and Tonopen (4.97 ± 3.33). Overall, differences in IOP were ≤ 3 mm Hg in 58% of eyes for Icare-Tonopen, 72% for Tonopen-Goldmann, and 62% for Icare-Goldmann.
  
  
  CONCLUSIONS
  IOP measurements using Icare rebound tonometry, Tonopen, and Goldmann tonometry are in excellent agreement following vitreoretinal surgery. However, Icare overestimates at IOP ≥ 23 and underestimates at IOP <10 mm Hg.
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Dilraj S
authors.initials: DS
authors.lastname: Grewal
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sandra S
authors.initials: SS
authors.lastname: Stinnett
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Folgar
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Schneider
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Lejla
authors.initials: L
authors.lastname: Vajzovic
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Asrani
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sharon F
authors.initials: SF
authors.lastname: Freedman
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Prithvi
authors.initials: P
authors.lastname: Mruthyunjaya
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina. Electronic address: paul.s.hahn@dm.duke.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Hahn
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014065:Tonometry, Ocular / Q000295:instrumentation* / Q000592:standards; D057586:Vitreoretinal Surgery