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Dirk van Norren talk at ISCEV 2025 Utrecht - 1970 Pisa - 2025 Utrecht, A Journey down memory lane

RETIREMENT TRIBUTE TO DR DAVID BIRCH

The Retina Foundation of the Southwest has created a tribute video to honor Dr David Birch's retirement. This can be viewed here.

2012 - Overview of the 2012 ISCEV survey of full-field electroretinography practice

It is a particular pleasure to contact you as your new Director of Standards and to thank everyone who completed our survey of ERG practice. We received an impressive 143 responses. As one respondent mentioned, it did take more than 5 minutes to complete, especially for those who took the time to add helpful comments.

The ERG survey was prepared as a co-operative effort with our outgoing Director of Standards, Michael Marmor, Ulrich Kellner and Ruth Hamilton. The data will inform the work of Prof Kellner and his ERG standards committee in preparation of the 2014 update of the ISCEV standard for full-field electroretinography. Below please find a brief synopsis of the survey results. The detailed replies are available as PDF.

If you have suggestions for the update of the ERG standard, please send them to Ulrich Kellner [kellneru@mac.com]. The committee will be in touch with ISCEV members for further input when the draft update is available.

Four of the five standard ERG tests are used routinely by >90% of labs

• 94-98% of respondents use the dark-adapted weak and standard flashes, the light-adapted single flash and the light-adapted flicker for routine clinical ERG testing.

ERG testing is less prevalent for standard oscillatory potentials and recommended dark-adapted strong flash ERGs

• 72% routinely record oscillatory potentials
  57% (79/139) routinely record the recommended strong (10 or 30) flash ERG. Of these 79 labs, 59 use 10 cds/m², 17 labs use 30 cds/m² (includes 3 labs that routinely record both) and six labs use other strong flash levels.

Non-standard (weaker or stronger) stimuli are used for some tests

• 3.5% record non-standard dark-adapted ERGs to a weak flash stimulus.
  5.1% record non-standard light-adapted single flash ERGs
  6.5% record non-standard dark-adapted single flash ERGs.
  6.5% use non-standard stimuli for dark-adapted strong flash ERGs
  8.8% use non-standard stimuli for light-adapted flicker ERGs
  10.7% record non-standard OPs.

Full-field ERG tests are reported as clinically valuable (routinely or occasionally) as follows

• 97.5% for light-adapted flicker ERGs
  94.9% for light-adapted (3.0) single flash ERGs
  94.5% for dark-adapted (3.0) ERG
  90.2% for dark-adapted (0.01) ERGs
  70% for dark-adapted OPs
  57.6% for recommended stronger flash ERGs (i.e. 70% of those who record this response)

A majority of respondents also record multifocal ERGs and pattern ERGs in their labs. The prevalence of other ERG tests (recorded often or sometimes)

• 94–98% of respondents use each of the dark-adapted weak and standard flashes
• Long-duration (on-off) ERGs: 62%
  A dark-adapted luminance-response series: 55%
  S-cone ERG: 48%
  A light-adapted luminance-response series (photopic hill): 41%
  Saturated a-wave for slope analysis: 29%
  Scotopic threshold response: 23%
  Double flash ERGs: 17%
  The early receptor potential: 8.1%
  Direct current ERGs: 4.8%
  ERGs with red and/or blue flash were mentioned in comments as additional or alternative stimuli.

Respondents report a range of calibration methods and frequencies and most, 94%, calibration their systems. Both adults and children are tested 89% of labs. The number of ERGs per year ranges from small units to very large clinical electrophysiology facilities (see figure).

Daphne L McCulloch, ISCEV Director of Standards

2008 - Multifocal Monuments around the world

An electrophysiological traveller's guide, inaugurated by Colin Barber: [PDF]

2005 - Drug Development and Clinical Trials – Special Symposium at ISCEV 2005 (Loch Lomond, Scotland)

Electroretinography: The FDA's Viewpoint by Wiley A Chambers Download Powerpoint presentation