Visual field and retinal nerve fiber layer comparisons in glaucoma.

Semiquantitative retinal nerve fiber layer (RNFL) scores given separately to diffuse and localized changes of the RNFL were correlated with the overall mean retinal sensitivity and visual field indexes calculated from 49 thresholds of the OCTOPUS program JO. The indexes have been developed to differentiate between generalized reduction and localized disturbances of the retinal sensitivity. The RNFL scores and visual field functions were highly correlated. Approximately 50% of the variation of the visual field functions could be accounted for by the RNFL loss scores. An adequate fit of visual field data on localized nerve fiber loss score was achieved by linear regression, whereas the diffuse nerve fiber loss score was improved by quadratic regression. This suggests that localized nerve fiber loss may be more directly associated with localized visual field disturbances than generalized fiber loss and that there may be a latency between the appearance of structural changes and generalized reduction of retinal sensitivity.