TAG Episode 28 - 18July2017: JOHNSON pet peeves in perimetry (mp3)

[This is the .mp3 un-enhanced version of this podcast. The AAC .m4a version has chapter markers and artwork embedded in the podcast to enhance the experience on devices/apps that support this, which includes most podcasting apps on iOS and Android devices. It is the preferred version for experiencing this podcast.]

Chris Johnson

I sat down with Chris Johnson at a recent American Glaucoma Society meeting to discuss some of my pet peeves about visual field testing and what lies on the horizon. Chris is Professor of Ophthalmology and Visual Sciences at the University of Iowa and a world renown Perimetry expert.

Episode Chapters:

1. Myopic tilted optic nerves; do we have a proper control group to compare these patients to? Liquid lens in HVF 3 corrects for spherical refractive error. Nasal steps often spill over the horizontal midline because we do not correct for tilt. SLO with microperimetry will compensate for this, not yet released at the time of this recording but is now available outside of North America e.g. Compass (Fundus Automated Perimetry) https://www.centervue.com/products/compass/

2. Flattening of Frequency of Seeing curve as defects gets worse, the VF gets less reliable because we don’t use bigger test targets when worse; i.e. the more damage, the higher the variability. Aside from increasing target size e.g. a size VI target, there is potential with Frequency Doubling perimetry to reduce this variability

3. Patchy loss: we don’t have good macular functional testing. Patchy loss testing such as Rare Bit perimetry by Lars Frisen: Frisén, L. New sensitive window on abnormal spatial vision: rarebit probing. Vision Res. 2002;42:1931–1939. https://www.ncbi.nlm.nih.gov/pubmed/12128022

4. Home testing with tablets or smartphones

5. Reached a plateau and now that imaging has been advancing, it’s time for a paradigm shift that correlates the structure and function


Production information:

This episode was originally recorded March 2015 during the Annual Meeting of the American Glaucoma Society in Coronado, CA using two Shure SM58 microphones with a Marantz PMD661 digital recorder. Mixing and sound levelling were FINALLY performed in July 2017 on a MacPro using Hindenberg Journalist Pro software. Narration was overdubbed using a Heil PR40 Microphone with Journalist Pro. Look for upcoming discussion with Ron Fellman and Murray Johnstone that were recorded in 2016 that are still sitting in the vault and then some new recordings are planned soon.

Opinions expressed in this podcast  are those of the speakers and are not intended to be taken as the standard of care for glaucoma treatment. Please always weigh the complete clinical picture and involve patients with any decisions in their care.


Robert M Schertzer, MD, MEd, FRCSC
podcast@iguy.org
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Although I closed down the West Coast Glaucoma Center after moving to the east coast in the Fall of 2013, the website is still alive as a resource for eye information at http://westcoastglaucoma.com
or http://iguy.tv/office

Theme music "Middle East Gold" ©Daniel Schertzer 2010 and published by Les Prods DOSWA Enr

This podcast © 2017 DOSWA Prods Enr/Robert M Schertzer MD. MEd, FRCSC