June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
Reducing detection time from 24 months to 9 months or less for rapid visual field loss in glaucoma
Author Affiliations & Notes
  • Benjamin T Backus
    Vivid Vision, Inc., San Francisco, California, United States
  • James J Blaha
    Vivid Vision, Inc., San Francisco, California, United States
  • Footnotes
    Commercial Relationships   Benjamin Backus, SUNY Research Foundation (P), Vivid Vision Inc (I), Vivid Vision Inc (E); James Blaha, Vivid Vision Inc (I), Vivid Vision Inc (E)
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 3390. doi:
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    • Get Citation

      Benjamin T Backus, James J Blaha; Reducing detection time from 24 months to 9 months or less for rapid visual field loss in glaucoma. Invest. Ophthalmol. Vis. Sci. 2021;62(8):3390.

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      © ARVO (1962-2015); The Authors (2016-present)

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Abstract

Purpose : Patients with rapidly progressing glaucoma must be identified quickly to receive aggressive treatment to save their vision. Progression is diagnosed with visual field tests, but current tests lack precision, with a test-retest variability of ~1.0 dB in mean sensitivity (MS) for moderate to severe glaucoma. New at-home tests with redesigned psychophysical procedures have recently made it practical to test 10 times in 5-10 days (Deiner, Damato & Ou, 2020. Implementing and Monitoring At-Home VR Oculo-kinetic Perimetry During COVID-19. Ophthal 127:1258). The additional data reduces test-retest variability by a factor of √10, to 0.3 dB. We asked how many months are needed to detect rapid progression (-2 dB/year) for a patient taking quarterly clusters of 10 tests, as compared to a conventional test quarterly or twice-yearly.

Methods : Simulations in Matlab modeled progression in 10,000 cases each at rates of 0 dB or -2 dB/year, respectively. Test-retest variability for single tests was 1.0 dB. Specificity was set to 0.95 and sensitivity to 0.8. The testing procedure continued until the fitted rate parameter for progression (the slopes of the regression lines) could be segregated by a boundary, with 95% of non-progressors below, and 80% of progressors above, the boundary.

Results : Detecting progression took 24 months for tests administered twice yearly, 18 mos for quarterly, but only 9 mos for 10-test clusters quarterly. Alternatively, specificity and sensitivity could be 99% and 98% respectively, for time-to-detect of 36, 27, and 12 months, respectively. Many glaucoma patients have test-retest variability < 1.0 dB. In a patient whose test-retest variability is 0.5, time-to-detect is 6 months for quarterly clusters. It is similarly reduced if the new at-home test has better test-retest variability than conventional tests.

Conclusions : Even by itself, at-home testing of visual fields using conventional psychophysical methods would greatly improve treatment of glaucoma. Additionally, new testing procedures that are less fatiguing for the patient mean that 10 tests can collected at a time, shortening the time to detect progression to as little as 6 months.

This is a 2021 ARVO Annual Meeting abstract.

 

Top: Simulated MS values from 4 testing protocols for one patient. Middle: Regression slopes for 50 patients with and without progression. Bottom: Accumulation of statistical power.

Top: Simulated MS values from 4 testing protocols for one patient. Middle: Regression slopes for 50 patients with and without progression. Bottom: Accumulation of statistical power.

 

Detection time (months). Colors correspond to curves in figure above.

Detection time (months). Colors correspond to curves in figure above.

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