Abstract
Purpose: :
To test the hypothesis that the depth of absolute visual field defects of glaucomatous patients as tested by threshold conventional automated perimetry would be quantifiable using Goldmann size V stimuli rather than standard size III stimuli.
Methods: :
Seventeen glaucomatous patients showing well established absolute defects when tested with a Humprey 750-II VFA (Carl Zeiss Medited, Inc.,Doublin CA, USA) perimeter (SITA-Standard strategy, program 24-2 or 30-2, Goldmann size III stimuli) were enrolled in this study. The worse eye from each patient was chosen. Each patient underwent first a further SITA-Standard, size III stimuli test and then a Fastpac, size V stimuli test. The Fastpac strategy was chosen because the use of size V stimuli is not allowed by the SITA-Standard strategy.
Results: :
As expected, differences between the results from size V and size III stimuli tests were statistically significant (p<0.001), with the absolute defects reduced when perimetry was performed using a size V stimulus.
Conclusions: :
Areas classified as absolute scotomas by standard automated perimetry are considered as blind and their real depth cannot be quantified. Our data support the hypothesis that such absolute defect don’t correspond to completely blind retinal areas. The use of size V stimuli should be useful during the follow up of glaucomatous patients with advanced disease and should also have implications in the patient disability assessment.
Keywords: perimetry • visual fields