LAUSR

OBJECTIVES To compare the ability of 24-2C and 10-2 test grids in measuring visual field global indices, identifying central visual field defects, and facilitating macular structure-function analysis with optical coherence tomography (OCT) scans in glaucoma suspects and glaucoma patients. DESIGN Prospective, cross-sectional study. PARTICIPANTS One eye from 131 glaucoma and 57 glaucoma suspect patients recruited from a referral-only university-based glaucoma clinic. METHODS Each subject underwent perimetric testing using 24-2C SITA-Faster and 10-2 SITA-Fast in random order, and Cirrus OCT macular imaging (Ganglion Cell Analysis) for structure-function correlations. MAIN OUTCOME MEASURES Visual field global indices (mean deviation, pattern standard deviation, binarized "cluster" pass/fail, and central mean sensitivity), number and proportion of visual field defects, and structure-function concordance with the Cirrus OCT deviation map following visual field location displacement for correspondence with underlying retinal ganglion cell position. RESULTS Global indices (mean deviation, pattern standard deviation, and central mean sensitivity) were similar between the 24-2C and 10-2 grids. The 10-2 detected more points of deficit compared to the 24-2C (p<0.0001 for all patients, p=0.006 for glaucoma patients). This was preserved when analysing the proportion of defects in the central visual field for all patients (p=0.02) but was not significantly different for glaucoma patients (p=0.051). The 10-2 identified more central "clusters" of 2+ contiguous points of deficit (p<0.0001). Structure-function comparisons performed at locations where visual field and OCT test locations were colocalised revealed greater concordance of structural and functional deficits using the 10-2 compared to the 24-2C (p<0.0001). The 10-2 took a median of 201 seconds, and the 24-2C a median of 154 seconds, corresponding to the different thresholding algorithms. CONCLUSIONS The 24-2C and 10-2 test grids return similar global indices of visual field performance and proportionally similar amounts of central visual field loss. The additional points in 10-2 grid returns more "clusters" of defects and a greater rate of structure-function concordance compared to the 24-2C test grid. Thus, the 24-2C can identify the presence of a clustered central visual field defect using similar probability criteria, whilst the 10-2 may be more useful in comprehensively characterising the defect and predicting central visual function.