Ability of 24-2C and 24-2 Grids to Identify Central Visual Field Defects and Structure-Function Concordance in Glaucoma and Suspects.
Abstract Purpose To compare the ability of 24-2 and 24-2C 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 100 glaucoma suspect and glaucoma patients (60 undergoing SITA-Faster testing on 24-2 and 24-2C; 40 undergoing SITA-Standard testing on 24-2 and SITA-Faster on 24-2C) were included in the study. Global visual field indices, test duration and pattern deviation results were extracted. The deviation map from Cirrus OCT Ganglion Cell Analysis (GCA) was extracted, and structure-function comparisons occurred after correction of visual field test stimulus location that stimulated the corresponding retinal ganglion cell. Results Global index results were similar between the 24-2 and 24-2C grids, and both identified a comparable number of clusters of visual field defects. Centrally, the 24-2C identified more clusters of defects compared to the 24-2, but this was not statistically significant. Although the 24-2C test locations resulted in more instances of structure-function concordance compared to the 24-2, half the locations in the 24-2C grid fell close to or outside the GCA grid when corrected for ganglion cell displacement. Conclusions The 24-2C returns similar global visual field indices compared to the 24-2, but tends to identify more clusters of central functional defects. Central structure-function concordance was better achieved using the 24-2C, but half of the visual field test locations do not coincide with a commonly used macular thickness scan.