Application of Virtual Visual Fields Yvonne Ou, MD Associate Professor of Ophthalmology Co-Director, Glaucoma Service Vice Chair for Postgraduate Education Department of Ophthalmology, UCSF Disclosures: None
“ “Since intertest (long-term) fluctuation is common, it is wise not to undertake a major therapeutic intervention based on a single examination. ” - R. Rand Allingham, Chandler & Grant’s Glaucoma
Slide about Medeiros study “…evidence-based guidance on the frequency of testing required to accurately distinguish the presence of progressive visual field losses from measurement variability remains elusive, but would be of immense benefit for the clinical management of patients with glaucoma.” Ophthalmology 2017;124:786-792. Smaller gains in the time to detect progression when testing increased from 2 to 3 times a year Ophthalmology 2017;124:786-792.
Slide about Medeiros study “..obtaining 2 reliable tests at baseline followed by semiannual testing and confirmation of progression through repeat testing in the initial years of follow-up may provide a good compromise for detecting progression, while minimizing the burden on health care resources in clinical practice.” Ophthalmology 2017;124:786-792. Do we really need to compromise? “You want a child, I want a dog. Can’t we compromise?” New Yorker, published July 23, 2001
“ Me: “Mr. Smith, how are you doing? Sorry for the wait.” “ Mr. Smith: “I HATE visual field testing!”
But what happens in reality? https://giphy.com/gifs/kHU8W94VS329y Limitations of traditional VF testing methods High cost Lack of portability Ergonomic limitations Need for highly skilled examiner Individual tests are Controlled lighting High fixation losses – High false positives environment inability to suppress noisy foveation reflex
Okulokinetic perimetry As developed by Bertil Damato, MD, PhD Thursday, 13 October 1983, 1 pm Hospital Library Courtesy of Bertil Damato OKP Glaucoma Screener: Version I Courtesy of Bertil Damato
Okulokinetic perimetry 15 Virtual Reality - OKP Portable wireless test Self-paced, automated instruction and training No need to control for lighting Utilizes “foveation reflex” Reduces user fatigue Current version with suprathreshold testing 16
How to perform the test On the fly customizability
In normal patients, how sensitive is VR-OKP for detecting the blind spot? Mean Test Duration Demographics Sensitivity in detecting blind spot 5 minutes 19 seconds 98.3% 60 Range (59/60 eyes) 4 minutes 37 seconds to 18 12 5 minutes 53 seconds Male Female Eyes Mean Age User-friendliness Safety Outcome 31 years adverse 0% events Discomfort and fatigue Range rated little to none 19 to 50 years 78 year-old female
78yo female - Loved VR since no eye covered - Didn’t have discomfort - “felt like just one screen” - VR VF ”less frustrating” Courtesy of James Blaha, Ben Backus, Bertil Damato, Mike Deiner, Manish Gupta and my patient
“ “Areas of existing damage are far more likely to demonstrate progressive loss, either by scotomatous enlargement or deepening, than undamaged areas. Therefore, it is useful to examine these areas more carefully when examining a series of visual fields.” - R. Rand Allingham, Chandler & Grant’s Glaucoma What the future holds… “Smart” algorithms that test areas of previous scotomas in more detail Threshold testing Home testing Test stimuli that challenge selectively vulnerable RGC subtypes Stay tuned…
Home testing is feasible Potential benefits of VR-oculokinetic perimetry Low cost Very portable Overcomes ergonomics Home testing Frequent testing may Built-in lighting Utilizes foveation reflex No need for highly environment skilled examiner overcome intertest variability
Thank you! UCSF Vivid Vision - Bertil Damato, MD, PhD - Ben Backus, PhD - Michael Deiner, PhD - James Blaha - Anwell Nguyen - Manish Gupta - Mary Lew - Megan Law, MD
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