The TsiogkaSpaeth grid in Indian patients with primary open-angle glaucoma: A cross-sectional diagnostic accuracy study

Purpose: To evaluate the diagnostic accuracy of an innovative visual field grid tool, the TsiogkaSpaeth (TS) Grid, in detecting visual field defects in patients with primary open-angle glaucoma (POAG) and to compare its performance with standard automated perimetry. Methods: This hospital-based cross-sectional study included 51 participants (73 eyes) with POAG and age-matched controls. All participants underwent comprehensive ophthalmic evaluation, TS Grid testing, and Humphrey Visual Field Analyzer (HFA) 24-2 SITA Standard testing as the reference standard. Diagnostic accuracy parameters including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristic (ROC) curve analysis were calculated. Correlations between TS Grid scores and standard automated perimetry indices (mean deviation [MD], pattern standard deviation [PSD], visual field index [VFI]) were analyzed. Results: The TS Grid demonstrated a sensitivity of 91.7%, a specificity of 89.2%, PPV of 89.2%, and NPV of 91.7%. The area under the ROC curve was 0.904, indicating excellent diagnostic accuracy. TS Grid scores showed strong positive correlation with MD and VFI and a negative correlation with PSD ( P < 0.001). Conclusion: The TS Grid is a reliable, low-cost, and portable tool for visual field assessment in POAG. Its high diagnostic accuracy and ease of use make it a valuable adjunct for screening and functional evaluation, particularly in resource-limited settings.