Saccadic reaction time in mirror image sectors across horizontal meridian in eye movement perimetry

Mazumdar, Deepmala; Meethal, Najiya S. Kadavath; George, Ronnie; Pel, Johan J. M. · 2021 · DOAJ

DOI: 10.1038/s41598-021-81762-y

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study investigates the diagnostic utility of saccadic reaction time (SRT) in eye movement perimetry (EMP) for detecting glaucomatous visual field defects. While SRT delays are known to occur in glaucoma, the specific behavior of SRT across hemi-field sectors—mirroring the anatomical arrangement of retinal nerve fiber layers—had not been previously explored. The authors aimed to establish normative limits for SRT in five superior and five inferior mirror-image sectors and evaluate whether asymmetry between these sectors could classify eyes as normal or glaucomatous, comparable to the Glaucoma Hemi-field Test (GHT) used in standard automated perimetry (SAP). The research was conducted in two phases. In the development phase, retrospective data from 60 healthy subjects (aged 20–70) were used to estimate normative limits for SRT. Probability scores were assigned to SRT delays at significance levels of 5%, 2.5%, 1%, and 0.5%. Probability Score Limits (PSL) were calculated for each of the five sector pairs based on the absolute difference between superior and inferior scores. In the evaluation phase, 30 healthy subjects and 30 glaucoma patients (15 mild, 15 moderate) were prospectively recruited. Participants underwent EMP using a 54-point test grid and an eye-tracking system, as well as SAP. SRT was defined as the time from stimulus onset to the initiation of a saccade toward the stimulus. The classification accuracy of EMP-based PSLs was assessed and compared against the clinical diagnosis established by SAP. Results indicated no statistically significant differences in SRT between mirror-image sectors in healthy subjects, confirming symmetrical behavior across the horizontal meridian. In the evaluation phase, the PSL at the 2.5% probability level demonstrated moderate classification accuracy, with a sensitivity of 70% and specificity of 77% for distinguishing glaucoma from healthy eyes. The Area Under the Curve (AUC) for PSLs ranged from 0.683 to 0.783. At the stricter 0.5% level, specificity increased to 83%, but sensitivity dropped to 53% due to misclassification of glaucomatous eyes. Conversely, the 5% level showed higher sensitivity but lower specificity. The study found that SRT delays in glaucoma patients were significantly higher than in controls, and the sector-based asymmetry analysis successfully identified defects in cases where SAP GHT indicated abnormalities. The findings suggest that analyzing SRT asymmetry across hemi-field sectors in EMP provides a viable method for detecting glaucomatous visual field loss. The moderate accuracy of the 2.5% PSL level indicates that SRT-based metrics can complement traditional threshold-based perimetry. By leveraging the physiological symmetry of healthy visual fields, this approach offers a refined tool for interpreting EMP reports, potentially aiding in the earlier or more precise diagnosis of glaucoma by capturing functional deficits reflected in reaction time delays rather than just sensitivity thresholds.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-prismaquant on 2026-06-26; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• useful field of view