Relating Standardized Automated Perimetry Performed with Stimulus Sizes III and V in Eyes With Field Loss due to Glaucoma and NAION

Objective: Standard automated perimetry (SAP) visual field (VF) results are more repeatable using Goldmann stimulus size V (stimV) 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 stimIII and stimV 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 (TD). 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 dB for stimIII and 24 dB for stimV. The difference between stimV and stimIII censored (0.0 +/- 1.9 dB) and uncensored (0.4 +/- 2.6 dB) TD pairings strongly 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 similar to that of the line of unity (m = 1). Conclusion: Censoring plus age correction is a valid method of comparison between stimIII and stimV SAP VFs with moderate to severe VF loss due to optic nerve disorders. Translational Relevance: StimIII and stimV TDs are interchangeable in clinical practice.