Related Experiment Video
Updated: Oct 19, 2026
Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
Published on: May 25, 2020
Stage-dependent differences in recalculated mean deviation between 24plus(1-2) and 24plus(1) test locations in
Hiroki Nomoto1, Chota Matsumoto2, Fumi Tanabe2
1Faculty of Medicine, Department of Ophthalmology, Kindai University, Sakai City, Osaka, Japan. nomoto@med.kindai.ac.jp.
Purpose:
To evaluate stage-dependent differences in mean deviation (MD) recalculated from the 24plus(1-2) and 24plus(1) test locations and to identify the MD range at which divergence between the reduced and full location sets exceeds a prespecified operational threshold in glaucoma.
Methods:
This retrospective, cross-sectional study included 394 eyes from 197 patients with glaucoma including preperimetric glaucoma (PPG). The 24plus(1) MD was recalculated from a subset of 36 test locations derived from the 24plus(1-2) grid. Glaucoma severity was classified as PPG, early, moderate, or advanced based on MD. Differences between the full and reduced location sets were assessed using cluster-adjusted Bland-Altman analysis and linear mixed-effects models. Mixed-effects logistic regression was applied to estimate the probability of exceeding a prespecified operational MD-difference threshold (|ΔMD|> 1 dB), with patient-level bootstrap confidence intervals.
Results:
The overall mean difference in recalculated MD was - 0.52 dB (95% limits of agreement: - 2.82 to 1.78 dB). The proportion of eyes with |ΔMD|> 1 dB was 1.9% in PPG, 17.8% in early glaucoma, 50.0% in moderate glaucoma, and 67.5% in advanced glaucoma. Worse MD was significantly associated with a higher probability of exceeding the prespecified operational MD-difference threshold (β = - 0.169; P < 0.001). MD values of - 5.4 dB (95% CI: - 7.0 to - 4.0) and - 11.9 dB (95% CI: - 14.1 to - 9.9) corresponded to 25% and 50% predicted probabilities of deviation, respectively.
Conclusion:
In this recalculation/subsampling analysis, 24plus(1)-derived MD was similar to 24plus(1-2)-derived MD in early glaucoma but diverged with advancing disease, particularly beyond approximately - 5 to - 6 dB, suggesting caution when interpreting 24plus(1)-derived MD in more advanced glaucoma.
