To evaluate the relationship between global indices of Humphrey standard automated perimetry (SAP, 30-2 SITA standard test), Humphrey Matrix frequency doubling technology (FDT, 30-2 threshold test), and Heidelberg Retina Tomograph (HRT II) parameters and measure the level of agreement among these 3 tests in classifying eyes as normal or abnormal.
The study included 1 eye of 29 ocular hypertensive and 56 glaucoma patients with a mean age of 60.9+/-10.5 years. All subjects had reliable visual fields and HRT measurements performed within a 2-week period. The eyes were classified as normal/abnormal according to visual field criteria and Moorfields regression analysis (MRA). Correlations between visual field indices (mean deviation and pattern standard deviation) and HRT parameters were analyzed using Spearman correlation coefficient (r) and the agreement between the tests in classifying eyes was defined with kappa value.
FDT Matrix mean deviation and pattern standard deviation parameters were found to be highly correlated with those of SAP (r=0.66 and 0.69, respectively). Visual field indices showed statistically significant correlations with cup area, rim area, cup/disc (C/D) area, linear C/D, cup shape, mean retinal nerve fiber layer thickness and retinal nerve fiber layer area parameters (P<0.05). Fifty-eight patients (68.2%) had abnormal results at least with 1 of the tests and 21 subjects (24.7%) had abnormal results with all 3 tests. The kappa values were 0.6 for SAP and Matrix (P<0.001), 0.33 for SAP and MRA (P=0.002), and 0.31 for Matrix and MRA (P=0.004).
FDT Matrix results are highly comparable with SAP in the assessment of glaucoma. Visual field global indices show statistically significant, but low-moderate correlations with most of the HRT parameters. The agreement among MRA and visual fields for abnormality is fair. Either HRT or visual fields may show the first evidence of glaucomatous damage; therefore, the combination of optic nerve head parameters and visual field results could improve glaucoma diagnosis and follow-up.