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E. Capris, P. Capris, G. Corallo, G. Calabria, M. Iester; Agreement to Detect Glaucomatous Visual Field Progression by Using Glaucoma Progression Analysis and Standard Humphrey Printout. Invest. Ophthalmol. Vis. Sci. 2009;50(13):2228.
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© ARVO (1962-2015); The Authors (2016-present)
To examine the level of agreement between clinicians in assessing progressive deterioration in visual field series using Glaucoma Progression Analysis (GPA) and standard Humphrey printout.
Each visual field was assessed by Humphrey Field Analyzer (HFA), program SITA standard 30-2 or 24-2 (Carl Zeiss Meditec, Inc., Dublin, CA). Mean Deviation (MD) and Pattern Standard Deviation (PSD) were considered at baseline and at the end of the follow-up. The first 3 fields in each series were exclude to minimize learning effects: the forth and fifth Full Threshold or SITA Standard exams were used as baseline. Three expert clinicians assessed the progression status of each series using both standard HFA printouts and the new Glaucoma Progression Analysis. The progression criteria adopted by the clinicians were similar to the GPA algorithm comparing single field printout with the baseline exams. The level of agreement between the clinicians was evaluated using a weighted kappa statistic. The Κ statistic was calculated interpreting as Κ < 0 indicating no agreement; Κ = 0.0 to 0.19, poor; Κ = 0.20 to 0.39, fair; Κ = 0.40 to 0.59, moderate; and Κ = 0.60 to 0.79, substantial; and Κ = 0.80 to 1.0, almost perfect agreement.
A total of 232 tests comprising 45 visual field series of 5,1 tests each were assessed by the three clinicians. The mean follow-up time was 5.8 +/- 1.75 years (mean +/- standard deviation). At baseline the mean MD was - 4.48 +/- 6.37 dB and at the end of the follow-up the mean MD was -5.49 +/- 7.4 dB, this difference was statistically significant (p=0.02). When the intra-observer agreement was evaluated, kappa statistic ranged from 0.8 to 0.533 among the three observers. When the inter-observer agreement was analyzed, if standard HFA printouts were used, kappa statistic ranged from 0.4 to 0.6, but when GPA was used, kappa statistic ranged from 0.16 to 0.6.
Intra-observer agreement was good by using either HFA printouts or GPA, while the inter-observer agreement was worsen. Slight differences in inter-observer agreement were found when standard GPA or HFA printouts were used.
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