Purpose: Standard automated perimetry (SAP) visual field (VF) results are more repeatable using Goldmann stimulus size V (size V) in eyes with moderate/severe deficits due to glaucoma. There are few reports relating VFs using stimulus size V and III, typically used in the clinic for glaucoma, and none for non-arteritic anterior ischemic optic neuropathy (NAION). We hypothesized that we could compare and relate the VFs with both stimuli for glaucoma and NAION.
Methods: We utilized 1992 same-day pairs of size III and size V SAP VFs using the 24-2 strategy for eyes with glaucoma or NAION. We explored the optimal threshold to censor the raw sensitivities, prior to calculating age-standardized total deviations (TDs). We determined the mean and standard deviation of the differences among all TD pairs. We computed a line of best fit to determine closeness to the line of unity.
Results: The ideal censoring conversion threshold was 21 decibel (dB) for size III and 24 dB for size V. The difference between size V and size III censored (0.0 ± 1.9 dB) and uncensored (0.4 ± 2.6 dB) TD pairings highly correlate with each other (r2 = 0.70, P < 0.001). The line of best fit from these pairings has a slope of 0.92, which is close to that of the line of unity (m = 1).
Conclusions: Censoring plus age correction is a valid method of comparison between size III and size V SAP VFs with moderate to severe VF loss due to optic nerve disorders.
Translational relevance: Size III and size V TDs are comparable in clinical practice.