title: Five-year risk of progression of ocular hypertension to primary open angle glaucoma. A population-based study.
abstract: OBJECTIVE
  To report the progression of ocular hypertension (OHT) to primary open angle glaucoma (POAG) during a 5-year follow up of a population-based sample.
  
  
  METHODS
  Twenty-nine patients diagnosed to have OHT and 110 randomly selected normals from a population-based study in 1995 were invited for ocular examination in 2000. All patients underwent a complete ophthalmic examination; including the daytime diurnal variation of intraocular pressure (IOP) and measurement of central corneal thickness (CCT). The "corrected" IOP was used for analysis. Progression to POAG was based on typical optic disc changes with corresponding field defects on automated perimetry.
  
  
  RESULTS
  Twenty-five of the 29 persons with OHT who could be contacted were examined. After correcting for CCT, two persons were reclassified as normal. Four of 23 (17.4%; 95% CI: 1.95-32.75) had progressed to POAG. One person amongst the 110 normals progressed to normal tension glaucoma (NTG). The relative risk of progression amongst OHT was 19.1 (95% CI: 2.2-163.4). All those who progressed had bilateral OHT. The mean and peak IOP in those who progressed was 25.4 mm Hg and 29.3 mm Hg compared to 23.9 mm Hg and 25.7 mm Hg in those who did not. Those who progressed had more than 8 mm Hg diurnal variation. The diurnal variation was less than 6 mm Hg in those who did not progress. No patient developed blindness due to glaucoma.
  
  
  CONCLUSIONS
  The 5-year incidence of POAG amongst OHT in this population was 17.4% (3.5% per year). Bilateral OHT, higher peak IOP and large diurnal variation may be the risk factors for progression.
authors.affiliation: L V Prasad Eye Institute, Vellore, India. ravithomas@lvpei.org
authors.forename: Ravi
authors.initials: R
authors.lastname: Thomas
authors.forename: Rajul
authors.initials: R
authors.lastname: Parikh
authors.forename: Ronnie
authors.initials: R
authors.lastname: George
authors.forename: Rajesh S
authors.initials: RS
authors.lastname: Kumar
authors.forename: Jayaprakash
authors.initials: J
authors.lastname: Muliyil
mesh_terms: D018450:Disease Progression; D005260:Female; D005902:Glaucoma, Open-Angle / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000150:complications / Q000503:physiopathology*; D009898:Optic Disk / Q000473:pathology; D012307:Risk Factors; D058609:Visual Field Tests; D014794:Visual Fields