title: ProTon tonometer determination of intraocular pressure in patients with scarred corneas.
abstract: OBJECTIVE
  To evaluate the measure of intraocular pressure (IOP) in patients with scarred corneas obtained from the affected and non-affected areas.
  
  
  METHODS
  Eighteen patients with small maculo-leucomatous corneal opacity following microbial keratitis were prospectively included in the study. Goldmann applanation tonometry was done first on the non-affected corneal surface. ProTon tonometry (PT) was then carried out on the same eye, to obtain IOP measurements from the non-affected (PT1) and the affected area (PT2) of the cornea. The IOP measurements were compared using a two-tail paired t test.
  
  
  RESULTS
  The mean of IOP measurements of PT 2 and PT1 was 22 mm of Hg (SD +/- 5.2) and 14.8 mm of Hg (SD +/- 5.4), respectively. The higher reading of PT2 was statistically significant ( P < 0.001). The mean Goldmann applanation tonometry was 14.6 mm of Hg (SD 5.4) and it did not differ significantly ( P = 0.86) from the PT1 readings of 14.8 mm of Hg (SD 5.4).
  
  
  CONCLUSIONS
  In patients with maculo-leucomatous corneal opacity, determination of IOP by ProTon tonometer varies from the affected to the non-affected area. The ProTon tonometer overestimates the level of IOP when it is applied to a leucomatous corneal opacity.
authors.affiliation: Department of Ophthalmology, Post Graduate Institute of Medical Research and Education, Chandigarh, India. aronkjain@yahoo.com
authors.forename: Arun K
authors.initials: AK
authors.lastname: Jain
authors.forename: Jaspreet
authors.initials: J
authors.lastname: Sukhija
authors.forename: Amod
authors.initials: A
authors.lastname: Gupta
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002921:Cicatrix / Q000473:pathology / Q000503:physiopathology*; D003315:Cornea / Q000473:pathology*; D003318:Corneal Opacity / Q000473:pathology / Q000503:physiopathology*; D004867:Equipment Design; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D014065:Tonometry, Ocular / Q000295:instrumentation*