title: Glaucomatous optic disc changes in the contralateral eye of unilateral normal pressure glaucoma patients.
abstract: OBJECTIVE
  To evaluate the optic disc for structural abnormalities in the contralateral eye of unilateral normal pressure glaucoma patients.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Fifty-three unilateral normal pressure glaucoma patients.
  
  
  METHODS
  Optic disc imaging with the Heidelberg Retina Tomograph (HRT).
  
  
  METHODS
  Optic disc structural parameters.
  
  
  RESULTS
  Of the contralateral (normal visual field) eyes, 79.2% were found to have an abnormal optic disc by HRT analysis. Of the glaucomatous (abnormal visual field) eyes, 94.3% were found to have an abnormal disc. The patterns of disc abnormality were defined as marked or moderate diffuse thinning of the neuroretinal rim (NRR) or broad or narrow focal thinning of the NRR. The most common pattern in the contralateral eyes was moderate diffuse thinning of the NRR (45.2%). The most frequently abnormal segments were the nasal superior (73. 8%) followed by the nasal inferior and the global NRR parameter (both 54.8%).
  
  
  CONCLUSIONS
  A high frequency of NRR thinning was found in the contralateral (normal visual field) eyes of unilateral normal pressure glaucoma patients by HRT analysis. Knowing whether these abnormalities predict future progression to the development of visual field abnormality must wait until longitudinal studies are completed. If a disc abnormality is shown to predict future field loss, then early identification will allow early treatment.
authors.affiliation: Glaucoma Unit, Moorfields Eye Hospital, City Road, London, UK.
authors.forename: G
authors.initials: G
authors.lastname: Wollstein
authors.forename: D F
authors.initials: DF
authors.lastname: Garway-Heath
authors.forename: D
authors.initials: D
authors.lastname: Poinoosawmy
authors.forename: R A
authors.initials: RA
authors.lastname: Hitchings
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D019721:Ophthalmoscopes; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D014054:Tomography; D014794:Visual Fields