A New Pattern Electroretinogram Paradigm Evaluated in Terms of User Friendliness and Agreement with Perimetry


      To assess ease of use of the pattern electroretinogram optimized for glaucoma screening (PERGLA) paradigm by a novice operator; to study test–retest variability of the PERGLA parameters; and to compare results from the PERGLA to those from perimetry.


      Cohort study.


      Twelve healthy control subjects and 16 patients with moderate to advanced glaucoma in at least 1 eye.


      Pattern electroretinograms were recorded simultaneously from both eyes using a commercially available testing station. Each participant underwent PERGLA procedures in 2 sessions. One eye of each subject was tested on contrast sensitivity perimetry (CSP) in which a 0.4 cycles/degree Gabor patch served as a stimulus. Central visual fields results from conventional automated perimetry (CAP) were obtained from patients’ records. Bland–Altman analysis was performed on PERGLA results to assess normal test–retest variability. Differences from mean normal (in decibels [dB]) were compared for PERGLA versus CSP and CAP.

      Main Outcome Measures

      Pattern electroretinogram amplitude, noise, phase, and test–retest variability (coefficient of variation); contrast sensitivity from CSP; perimetric sensitivity from CAP; and differences from mean normal for PERGLA, CSP, and CAP.


      The mean log amplitude (0.08±0.12 log μV) and the mean phase (1.92±0.07 π rad) for the control group were consistent with published PERGLA norms, as was test–retest variability for both amplitude (coefficient of variation [CV] = 8.2±7.0%) and phase (CV = 1.1±0.9%). The mean signal-to-noise ratio (8.7±4.5) was lower than published norms. The test–retest variability increased as PERGLA log amplitude decreased (R2>0.12, P<0.05). On average, differences from mean normal were similar for PERGLA versus CSP and for PERGLA versus CAP (mean differences<0.5 dB) with 95% confidence intervals near ±4 dB in both comparisons.


      A novice operator successfully replicated published PERGLA norms in a young control group for amplitude, phase, and repeatability. Higher test–retest variability was found in eyes with smaller signals. On average, PERGLA results were in reasonable agreement with those from perimetry, although there existed large individual differences which may limit the usage of PERGLA in screening or in following progression of glaucoma.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic and Personal
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Ophthalmology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Viswanathan S.
        • Frishman L.J.
        • Robson J.G.
        The uniform field and pattern ERG in macaques with experimental glaucoma: removal of spiking activity.
        Invest Ophthalmol Vis Sci. 2000; 41: 2797-2810
        • Korth M.
        • Horn F.
        • Storck B.
        • Jonas J.
        The pattern-evoked electroretinogram (PERG): age-related alterations and changes in glaucoma.
        Graefes Arch Clin Exp Ophthalmol. 1989; 227: 123-130
        • Bach M.
        • Sulimma F.
        • Gerling J.
        Little correlation of the pattern electroretinogram (PERG) and visual field measures in early glaucoma.
        Doc Ophthalmol. 1998; 94: 253-263
        • Garway-Heath D.F.
        • Holder G.E.
        • Fitzke F.W.
        • Hitchings R.A.
        Relationship between electrophysiological, psychophysical, and anatomical measurements in glaucoma.
        Invest Ophthalmol Vis Sci. 2002; 43: 2213-2220
        • Hood D.C.
        • Xu L.
        • Thienprasiddhi P.
        • et al.
        The pattern electroretinogram in glaucoma patients with confirmed visual field deficits.
        Invest Ophthalmol Vis Sci. 2005; 46: 2411-2418
        • Porciatti V.
        • Ventura L.M.
        Normative data for a user-friendly paradigm for pattern electroretinogram recording.
        Ophthalmology. 2004; 111: 161-168
        • Heijl A.
        • Lindgren A.
        • Lindgren G.
        Test-retest variability in glaucomatous visual fields.
        Am J Ophthalmol. 1989; 108: 130-135
        • Piltz J.R.
        • Starita R.J.
        Test-retest variability in glaucomatous visual fields [letter].
        Am J Ophthalmol. 1990; 109: 109-111
        • Henson D.B.
        • Chaudry S.
        • Artes P.H.
        • et al.
        Response variability in the visual field: comparison of optic neuritis, glaucoma, ocular hypertension, and normal eyes.
        Invest Ophthalmol Vis Sci. 2000; 41: 417-421
        • Harwerth R.S.
        • Crawford M.L.
        • Frishman L.J.
        • et al.
        Visual field defects and neural losses from experimental glaucoma.
        Prog Retin Eye Res. 2002; 21: 91-125
        • Swanson W.H.
        • Birch E.E.
        Extracting thresholds from noisy psychophysical data.
        Percept Psychophys. 1992; 51: 409-422
        • Bland J.M.
        • Altman D.G.
        Statistical methods for assessing agreement between two methods of clinical measurement.
        Lancet. 1986; 1: 307-310
        • Bland J.M.
        • Altman D.G.
        Measurement error.
        BMJ. 1996; 313: 744
        • Hood D.C.
        • Greenstein V.C.
        • Odel J.G.
        • et al.
        Visual field defects and multifocal visual evoked potentials: evidence of a linear relationship.
        Arch Ophthalmol. 2002; 120: 1672-1681
        • Heijl A.
        • Lindgren G.
        • Olsson J.
        Normal variability of static perimetric threshold values across the central visual field.
        Arch Ophthalmol. 1987; 105: 1544-1549
      1. Otto T, Bach M. Retest variability and diurnal effects in the pattern electroretinogram. Doc Ophthalmol 1996 -1997;92: 311-23.

        • Ventura L.M.
        • Porciatti V.
        Restoration of retinal ganglion cell function in early glaucoma after intraocular pressure reduction: a pilot study.
        Ophthalmology. 2005; 112: 20-27
        • Drasdo N.
        • Aldebasi Y.H.
        • Chiti Z.
        • et al.
        The S-cone PHNR and pattern ERG in primary open angle glaucoma.
        Invest Ophthalmol Vis Sci. 2001; 42: 1266-1272
        • Ventura L.M.
        • Porciatti V.
        • Ishida K.
        • et al.
        Pattern electroretinogram abnormality and glaucoma.
        Ophthalmology. 2005; 112: 10-19
        • Graham S.L.
        • Drance S.M.
        • Chauhan B.C.
        • et al.
        Comparison of psychophysical and electrophysiological testing in early glaucoma.
        Invest Ophthalmol Vis Sci. 1996; 37: 2651-2662