title: The structure-function relationship in eyes with glaucomatous visual field loss that crosses the horizontal meridian.
abstract: OBJECTIVE
  To evaluate the relationship between visual field loss and glaucomatous optic discs in eyes in which field loss spreads across the horizontal meridian.
  
  
  METHODS
  Ninety-six patients with glaucoma (9 advanced, 60 moderate, and 27 early) with 2 successive abnormal fields were included. Standard achromatic automated perimetry defects were identified with a nerve fiber bundle map to identify abnormal sectors. Crossover was present if the superior and inferior sectors at the horizontal meridian (nasal, central, or temporal) were both abnormal. Optic disc damage was assessed by masked grading of simultaneous stereophotographs.
  
  
  RESULTS
  Only 30% (29) of glaucomatous eyes showed crossover, and only 2 of those eyes had early loss. The most frequent pattern of visual field loss (41% of eyes) was single hemifield damage with defects in contiguous sectors. Regardless of the pattern or severity of visual loss, most eyes (66 [69%] of 96) had both superior and inferior optic disc damage.
  
  
  CONCLUSIONS
  Early glaucomatous visual field loss rarely crosses the horizontal meridian, but defects in both hemifields at the horizontal meridian are more common in more advanced field loss. In 26 (90%) of 29 eyes with crossover, it could be explained by changes at the optic nerve head.
authors.affiliation: Department of Ophthalmology, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0946, USA.
authors.forename: Catherine
authors.initials: C
authors.lastname: Boden
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Sample
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Boehm
authors.forename: Christiana
authors.initials: C
authors.lastname: Vasile
authors.forename: Radha
authors.initials: R
authors.lastname: Akinepalli
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D010781:Photography; D011446:Prospective Studies; D012189:Retrospective Studies; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests; D014794:Visual Fields