Detection of optic neuropathy in glaucomatous eyes with normal standard visual fields using a test battery of short-wavelength automated perimetry and pattern electroretinography

To evaluate the clinical use of a test battery of short-wavelength automated perimetry (SWAP), frequency-doubling technology (FDT) perimetry, and pattern-electroretinography (PERG) in patients with definite primary open-angle glaucoma (POAG) but normal results on standard automated perimetry (SAP). Prospective, comparative, observational case series. Thirty-six patients with POAG with standard visual field defects in one eye and normal standard visual fields in the contralateral eye and 36 normal controls were enrolled. SWAP, PERG, FDT, and SAP were performed in all eyes, and global indices and amplitudes were used for statistical analysis. When contralateral POAG eyes with asymmetric glaucomatous damage was compared, a paired t test showed significant differences in SAP mean deviation (MD) ( P < 0.0001), SWAP-MD ( P = 0.0003), FDT-MD ( P = 0.0008), and PERG amplitudes ( P < 0.0001). When comparing between POAG eyes with normal results on SAP and normal controls, Student’s t test showed significant differences for SWAP-MD ( P < 0.0001), FDT-MD ( P = 0.0006), PERG N1P1-amplitude ( P = 0.0486) and P1N2-amplitude ( P < 0.0001); receiver operating characteristic analysis revealed promising accuracy for SWAP-MD of 73.6% ( P < 0.0001). SWAP-MD ( P < 0.0001) and FDT-MD ( P < 0.0001) correlated significantly with SAP-MD and with each other (range, P < 0.0001 to P = 0.0020). Regression analysis revealed that PERG P1N2-amplitude could improve the power of SWAP-MD from 73.6% to detect early POAG in eyes with normal results on SAP to an accuracy of 81.9%. A test battery of SWAP-MD and PERG P1N2-amplitude could detect glaucomatous optic neuropathy in POAG eyes with normal standard visual fields, whereas FDT-MD and SWAP-MD significantly correlated with each other and with SAP-MD. All tests were able to detect the eye with the more severe glaucomatous optic neuropathy in patients with asymmetric POAG.