Estimating percent misdiagnosis when applying SITA-Standard criteria to SITA-Fast and SITA-Faster

Abstract

Purpose : An increasing number of glaucoma clinics are transitioning from SITA-Standard to SITA-Fast and SITA-Faster. We estimate percent misdiagnosis when applying SITA-Standard criteria for classifying glaucoma severity and the rate of MD worsening to SITA-Fast and SITA-Faster.

Methods : A total of 392,654 24-2 SITA-Standard, SITA-Fast and SITA-Faster visual fields (VFs) from 42,035 glaucoma and glaucoma suspect eyes with at least 5 VFs over follow-up between January 1997 and June 2023 at the Wilmer Eye Institute were analyzed. To estimate percent misdiagnosis, we constructed “within 6-month” retest distributions to compare SITA-Standard, SITA-Fast and SITA-Faster sensitivities. Each “within 6-month” retest distribution consisted of all sensitivities measured by a given test strategy within 6 months of a SITA-Standard measured baseline dB value. Expected sensitivities — means of the retest distributions — and expected mean deviation (MD) values were compared between test strategies, and used to adjust Hodapp-Parish-Anderson (HPA) criteria for SITA-Fast and SITA-Faster. Percent misdiagnosis of glaucoma severity was estimated by comparing HPA criteria to adjusted HPA criteria. Percent misdiagnosis of MD worsening was estimated by applying linear regression to expected MD values, and comparing the number of eyes below different criterion rates of worsening for different test strategies.

Results : HPA cutoffs for for partitioning MD into “severe”, “moderate” and “mild” should be adjusted from –12 dB and –6 dB for SITA-Standard to –10.8 dB and –5.3 dB for SITA-Fast, and –10 dB and –5.2 dB for SITA-Faster. Estimated percent misdiagnosis of moderate glaucoma as mild was 21.5% for SITA-Fast and 22.3% for SITA-Faster, while estimated percent misdiagnosis of severe glaucoma as moderate was 19.9% for SITA-Fast and 30.2% for SITA-Faster. Estimated percent misdiagnosis of rapid (>90^th percentile) MD worsening as moderate (75-90^th percentile)was 9.8% for SITA-Fast and 22.7% for SITA-Faster, while estimated percent misdiagnosis of moderate MD worsening as mild was 7.6% for SITA-Fast and 15.4% for SITA-Faster.

Conclusions : Potentially significant levels of misdiagnosis may result when applying SITA-Standard based criteria for classifying glaucoma severity and the rate of MD worsening to SITA-Fast and SITA-Faster. Classification criteria should be appropriately adjusted when using SITA-Fast or SITA-Faster.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.