Pattern electroretinogram and psychophysical tests of visual function for discriminating between healthy and glaucoma eyes

Abstract

Purpose: To compare the diagnostic accuracy of the pattern electroretinogram (pattern ERG) to that of standard automated perimetry (SAP), short-wavelength automated perimetry (SWAP), and frequency-doubling technology (FDT) perimetry for discriminating between healthy and glaucomatous eyes.

Design: Cross-sectional study.

Methods: Eighty-three eyes of 42 healthy recruits and 92 eyes of 54 glaucoma patients (based on optic disc appearance) from the University of California, San Diego, Diagnostic Innovations in Glaucoma Study were tested with pattern ERG for glaucoma detection (PERGLA; Lace Elettronica, Pisa, Italy), SAP, SWAP, and FDT within 9 months. Receiver operating characteristic (ROC) curves were generated and compared for pattern ERG amplitude and SAP, SWAP, and FDT mean deviation and pattern standard deviation (PSD). Sensitivities and specificities were compared and agreement among tests was described.

Results: The area under the ROC curve for pattern ERG amplitude was 0.744 (95% confidence interval = 0.670, 0.818). The ROC curve area was 0.786 (0.720, 0.853) for SAP PSD, 0.732 (0.659, 0.806) for SWAP PSD, and 0.818 (0.758, 0.879) for FDT PSD. At 95% specificity, sensitivities of SAP and FDT PSD were significantly higher than that of pattern ERG amplitude; at 80% specificity, similar sensitivities were observed among tests. Agreement among tests was slight to moderate.

Conclusion: The diagnostic accuracy of the pattern ERG amplitude was similar to that of SAP and SWAP, but somewhat worse than that of FDT. Nevertheless, the pattern ERG may hold some advantage over psychophysical testing because of its largely objective nature.

(c) 2010 Elsevier Inc. All rights reserved.

Figures

Figure 1

Areas under the receiver operating characteristic (ROC) curves for discriminating between healthy and patient eyes for pattern electroretinogram (ERG) for glaucoma detection amplitude and standard automated perimetry (SAP), short-wavelength automated perimetry (SWAP) and frequency doubling technology perimetry (FDT) mean deviation (MD) and pattern standard deviation (PSD). The area under the ROC curve for pattern ERG for glaucoma detection amplitude (0.744) is significantly smaller than that of FDT PSD (0.818). The area under the ROC curve for SWAP MD (0.570) is significantly smaller than that of all other parameters.

Figure 2

Venn diagram showing the number of glaucomatous optic neuropathy eyes with abnormal results at the 95% specificity cut-off for pattern electroretinogram (ERG) for glaucoma detection amplitude, standard automated perimetry (SAP) pattern standard deviation (PSD), short-wavelength automated perimetry (SWAP) PSD, and frequency-doubling technology perimetry (FDT) PSD. 38 glaucomatous optic neuropathy eyes were classified as within normal limits by all four tests.

Figure 3

Venn diagram showing the number of glaucomatous optic neuropathy eyes with abnormal results at the 80% specificity cut-off for pattern electroretinogram (ERG) for glaucoma detection amplitude, standard automated perimetry (SAP) pattern standard deviation (PSD), short-wavelength automated perimetry (SWAP) PSD, and frequency doubling technology perimetry (FDT) PSD. 14 glaucomatous optic neuropathy eyes were classified as within normal limits by all four tests.