title: Evaluation of the structure-function relationship in glaucoma.
abstract: OBJECTIVE
  While glaucoma is evaluated on the basis of structural and functional test results, the spatial relationship between structure and function is not well defined. This study produces a topographical map to demonstrate how sectors of the optic nerve head (ONH) are related to locations in the visual field, using empiric cross-sectional patient data.
  
  
  METHODS
  One hundred nine subjects with healthy eyes and 166 subjects with diagnosed or suspected glaucoma (one test per patient) were evaluated using a retina tomograph and white-on-white standard automated perimetry (SAP). The tomograph ONH images were divided into 36 sectors; and the sector rim areas normalized to account for changes in the total rim area. These were then correlated with SAP thresholds. For each visual field location, a map was produced indicating the strength of correlation between the normalized sector rim areas and thresholds.
  
  
  RESULTS
  The highest correlation between a sector's normalized rim area and a SAP location's sensitivity was 0.520. Twenty-seven of the 52 non-blind spot SAP locations exhibited a correlation greater than 0.2 with at least one ONH sector. Locations in the superior hemifield were usually best correlated with the polar inferior temporal sectors of the ONH; locations in the inferior hemifield were usually best correlated with the polar superior temporal sectors of the ONH.
  
  
  CONCLUSIONS
  A map relating regions of the ONH to SAP test locations has been produced. This map may be useful in elucidating the structure-function relationship, particularly for cases of localized glaucomatous loss.
authors.affiliation: Discoveries In Sight, Devers Eye Institute, Portland, OR 97208, USA. sgardiner@discoveriesinsight.org
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Gardiner
authors.forename: Chris A
authors.initials: CA
authors.lastname: Johnson
authors.forename: George A
authors.initials: GA
authors.lastname: Cioffi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields