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Purpose: To establish the extent of agreement for ISCEV standard reference pattern reversal VEPs (prVEPs) acquired at three European centres, to determine any effect of sex, and to establish reference intervals from birth to adolescence., Methods: PrVEPs were recorded from healthy reference infants and children, aged 2 weeks to 16 years, from three centres using closely matched but non-identical protocols. Amplitudes and peak times were modelled with orthogonal quadratic and sigmoidal curves, respectively, and two-sided limits, 2.5th and 97.5th centiles, estimated using nonlinear quantile Bayesian regression. Data were compared by centre and by sex using median quantile confidence intervals. The 'critical age', i.e. age at which P100 peak time ceased to shorten, was calculated., Results: Data from the three centres were adequately comparable. Sex differences were not clinically meaningful. The pooled data showed rapid drops in P100 peak time which stabilised by 27 and by 34 weeks for large and small check widths, respectively. Post-critical-age reference limits were 87-115 ms and 96-131 ms for large and small check widths, respectively. Amplitudes varied markedly and reference limits for all ages were 5-57 μV and 3.5-56 μV for large and small check widths, respectively., Conclusions: PrVEP reference data could be combined despite some methodology differences within the tolerances of the ISCEV VEP Standard, supporting the clinical benefit of ISCEV Standards. Comparison with historical data is hampered by lack of minimum reporting guidelines. The reference data presented here could be validated or transformed for use elsewhere., (© 2023. The Author(s).)

This document developed by the International Society for Clinical Electrophysiology of Vision (ISCEV) provides guidance for calibration and verification of stimulus and recording systems specific to clinical electrophysiology of vision. This guideline provides additional information for those using ISCEV Standards and Extended protocols and supersedes earlier Guidelines. The ISCEV guidelines for calibration and verification of stimuli and recording instruments (2023 update) were approved by the ISCEV Board of Directors 01, March 2023., (© 2023. The Author(s).)

The full-field electroretinogram (ERG) is a mass electrophysiological response to diffuse flashes of light and is used widely to assess generalized retinal function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV), presents an updated and revised ISCEV Standard for clinical ERG testing. Minimum protocols for basic ERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis, monitoring and inter-laboratory comparisons, while also responding to evolving clinical practices and technology. The main changes in this updated ISCEV Standard for clinical ERGs include specifying that ERGs may meet the Standard without mydriasis, providing stimuli adequately compensate for non-dilated pupils. There is more detail about analysis of dark-adapted oscillatory potentials (OPs) and the document format has been updated and supplementary content reduced. There is a more detailed review of the origins of the major ERG components. Several tests previously tabulated as additional ERG protocols are now cited as published ISCEV extended protocols. A non-standard abbreviated ERG protocol is described, for use when patient age, compliance or other circumstances preclude ISCEV Standard ERG testing., (© 2022. The Author(s).)

Introduction: Establishing robust reference intervals for clinical procedures has received much attention from international clinical laboratories, with approved guidelines. Physiological measurement laboratories have given this topic less attention; however, most of the principles are transferable., Methods: Herein, we summarise those principles and expand them to cover bilateral measurements and one-tailed reference intervals, which are common issues for those interpreting clinical visual electrophysiology tests such as electroretinograms (ERGs), visual evoked potentials (VEPs) and electrooculograms (EOGs)., Results: The gold standard process of establishing and defining reference intervals, which are adequately reliable, entails collecting data from a minimum of 120 suitable reference individuals for each partition (e.g. sex, age) and defining limits with nonparametric methods. Parametric techniques may be used under some conditions. A brief outline of methods for defining reference limits from patient data (indirect sampling) is given. Reference intervals established elsewhere, or with older protocols, can be transferred or verified with as few as 40 and 20 suitable reference individuals, respectively. Consideration is given to small numbers of reference subjects, interpretation of serial measurements using subject-based reference values, multidimensional reference regions and age-dependent reference values. Bilateral measurements, despite their correlation, can be used to improve reference intervals although additional care is required in computing the confidence in the reference interval or the reference interval itself when bilateral measurements are only available from some of subjects., Discussion: Good quality reference limits minimise false-positive and false-negative results, thereby maximising the clinical utility and patient benefit. Quality indicators include using appropriately sized reference datasets with appropriate numerical handling for reporting; using subject-based reference limits where appropriate; and limiting tests for each patient to only those which are clinically indicated, independent and highly discriminating., (© 2021. The Author(s).)

The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for visual evoked potentials (VEPs) describes a minimum procedure for clinical VEP testing and encourages more extensive testing. This ISCEV extended protocol is an extension to the VEP standard. It describes procedures for recording multiple VEPs to a range of sizes of pattern stimuli to establish the VEP spatial frequency limit (threshold) and for relating this limit to visual acuity.

The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum protocol for clinical testing but encourages additional ERG testing when appropriate. This ISCEV extended protocol describes methods to record and evaluate a light-adapted (LA) ERG stimulus-response series with increasing flash strengths. The LA ERG stimulus-response series (also referred to as the luminance-response or intensity-response series in the published literature) can characterise generalised cone system function more comprehensively than the ISCEV standard LA ERGs alone. The amplitude of LA ERG a-waves, arising from cones and cone off-bipolar cells, typically shows a saturating function. The LA ERG b-wave amplitudes, which arise primarily from activity of retinal bipolar cells, show an amplitude peak followed by a nonzero plateau (the "photopic hill" phenomenon). This ISCEV extended protocol specifies a stimulus-response series suitable to evaluate generalised dysfunction affecting the LA retina, to aid in distinguishing between the on- and off-responses of the cone system and to monitor ERG changes in these characteristics. The LA ERG stimulus-response series for a- and b-waves is recorded to a sequence of nine flash stimuli ranging from 0.03 to 300 cd s m -2 , superimposed on a standard background of 30 cd m -2 . A shorter protocol is also presented to measure the mid-range of the function (the "photopic hill") using 5 flash stimuli.

The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum procedure, but encourages more extensive testing. This ISCEV extended protocol describes an extension to the ERG standard, namely the dark-adapted (DA) red flash ERG. The DA red flash ERG can be incorporated conveniently within the ISCEV standard ERG protocol after a minimum of 20-min DA and recorded after the DA 0.01 ERG to a flash strength of 0.3 phot cd s m -2 , eliciting a waveform with two positive peaks in healthy individuals. The first positive component is the cone-mediated x-wave with a peak at 30-50 ms; the second is a rod-mediated b-wave with a peak time of approximately 100 ms. Shorter DA times may be desirable to shorten the recording time or to alter the prominence of the early cone-mediated x-wave relative to the rod-mediated b-wave. The DA red flash ERG is used to aid the diagnosis of achromatopsia (rod monochromacy), cone dystrophy and other forms of cone system dysfunction, including "Bradyopsia" (RGS9/R9AP-retinopathy), when the DA red flash ERG x-wave is preserved in the absence of ISCEV standard LA ERGs. The DA red flash ERG can also help determine the origin of residual DA ERGs in cases of severe rod dysfunction, for example in disorders such as vitamin A deficiency, fundus albipunctatus (RDH5-retinopathy), Oguchi disease (SAG- or GRK1-retinopathy) and some rod-cone dystrophies. To shorter DA periods, the x-wave may be elicited without the following rod b-wave, shown to be helpful in abbreviated protocols for children.

This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV), presents an updated and revised ISCEV Standard for full-field clinical electroretinography (ffERG or simply ERG). The parameters for Standard flash stimuli have been revised to accommodate a variety of light sources including gas discharge lamps and light emitting diodes. This ISCEV Standard for clinical ERGs specifies six responses based on the adaptation state of the eye and the flash strength: (1) Dark-adapted 0.01 ERG (rod ERG); (2) Dark-adapted 3 ERG (combined rod-cone standard flash ERG); (3) Dark-adapted 3 oscillatory potentials; (4) Dark-adapted 10 ERG (strong flash ERG); (5) Light-adapted 3 ERG (standard flash "cone" ERG); and (6) Light-adapted 30 Hz flicker ERG. ISCEV encourages the use of additional ERG protocols for testing beyond this minimum standard for clinical ERGs.

Purpose: To describe the appearance and maturation of dark-adapted oscillatory potentials (OPs) in electroretinograms (ERGs) recorded from preterm infants, and to determine any effect of retinopathy of prematurity (ROP)., Methods: Dark-adapted ERGs were recorded in conjunction with screening for ROP and at outpatient follow-up, using a flash luminance of 11.3 scot cd s m(-2) (4.06 phot cd s m(-2)). Eligible infants were born before 31 weeks' gestation and/or weighed ≤1,250 grams at birth., Results: Presence or absence of OPs was established for 68 ERG recordings from 38 infants at maturities ranging from 30 weeks' postmenstrual age (PMA) to 28 weeks' post-term corrected age. 20 infants did not develop ROP, eight developed stage 1, one stage 2 and one stage 3 disease which regressed spontaneously. Eight infants received treatment for threshold ROP. OPs were present in 50 % of infants at 36 weeks' PMA and in all by 50 weeks' PMA. The earliest appearance of OPs was at 30+5 weeks' PMA. Individual OP amplitudes increased and peak time of individual OPs decreased with increasing maturity. For infants with threshold ROP summed OP amplitudes tended to be smaller prior to treatment (6.5 vs 9.9μV, P = 0.09) and were significantly smaller by 50 weeks' PMA (14 vs 30μV, P = 0.007). OP1 was less likely to be present in infants who developed stage 3 or worse ROP (P = 0.000)., Conclusions: Dark-adapted OPs are recordable in some preterm infants from 30 weeks' PMA. Relative suppression of early OPs is a potential marker for developing ROP.

This study characterizes differences in human ERGs based on ocular pigmentation. Light- and dark-adapted luminance-response (LR) series for a-, b- and i-waves and light-adapted oscillatory potentials (OPs) were recorded in 14 healthy volunteers (7 blue-eyed Caucasians; 7 brown-eyed Asians, aged 20-22 years). Amplitude interpolations were by logistic growth (Naka-Rushton), Gaussian or the combined 'photopic hill' functions. Implicit times (IT) for dark-adapted a- and b-waves, and for light-adapted a-, b- and i-waves were earlier in the blue-eyed group than in the brown-eyed group across all flash strengths (P < 0.05). For dark-adapted ERGs, saturated a-wave amplitude was larger for blue eyes (397 vs. 318 μV, P < 0.05) as was the a-wave to strong flash (10 cd·s/m(2); 357 vs. 293 μV, P < 0.05) and the b-wave to ISCEV standard 0.01 (354 vs. 238 μV, P < 0.05). Light-adapted b-waves for midrange flash stimuli were much larger for the blue-eyed group (photopic hill, Gaussian peak: 155 vs. 82 μV, P < 0.001) with no difference in saturated amplitudes. Similarly, interpolated i-wave amplitudes were larger (48 vs. 18 μV, P < 0.01). For a light-adapted 2.6 stimulus, a- and b-waves were larger for the blue-eyed group (52 vs. 39 μV; 209 vs. 133 μV, P < 0.01) as were OP4 and OP5 (37.2 vs. 15.6 μV; 47.5 vs. 22.2 μV, P < 0.01), but OP1-OP3 did not differ. ERGs have shorter ITs in people with blue irides than in those with dark pigmentation. Amplitude differences are highly non-linear and substantially larger from eyes with light pigmentation for components thought to be associated with the OFF retinal pathways.

Maturation of the electroretinogram (ERG) reflects retinal development. Serial ERGs recorded from a preterm infant between 30 and 50 weeks after conception showed rapid maturation. A transient loss of retinal sensitivity coincided with clinical signs of stage 2 retinopathy of prematurity (ROP).