Central-most Visual Field Defects in Early Glaucoma

Precis: This study demonstrates the substantial association between visual field (VF) defect within the central-most 4 points in 24-2 VF and the VF defect exhibited by 10-2 test pattern relative to the initial defect in 24-2 VF. Purpose: To evaluate the significance of central-most visual field defects (CMVFDs) in 24-2 VF in early glaucoma. Methods: This cross-sectional study examined 29 eyes of 28 glaucoma patients with CMVFDs. CMVFD was defined as a glaucomatous defect with at least 1 abnormal point at P<1% within the central 5 degrees on 3 consecutive 24-2 VF tests. 10-2 VFs were categorized into 3 groups by severity of pattern defects: deep arcuate, partial arcuate, and minimal defect. The deep arcuate group was interpreted as the most severe defect on the 10-2 VF. Mann-Whitney test was used to compare the perimetric parameters differences between 24-2 VFs with CMVFD and 10-2 VFs related to the initial defect. Results: CMVFD was observed in 82% eyes, predominantly in the superior hemifield (86%). Arcuate-like defects (72%) on the 10-2 VF were mostly in superior hemifield (82%). The deep arcuate group showed significantly worse mean deviation (MD) and pattern standard deviation (PSD), (MD= -9.1 +/- 4, PSD =10.7 +/- 2.1 dB), than partial arcuate and minimal defect groups (all P<0.001). Eyes with deep arcuate defect had severely depressed defect depth (-26 to -35 dB) and low sensitivity (<0 to 10 dB) at abnormal points in the central 5 degrees in 24-2 VF. A significant difference among deep arcuate, partial arcuate (P<0.001), and minimal defect groups (P<0.001) was observed at abnormal points' threshold sensitivity and defect depth. Conclusions: Given the significance and effect of perimetric factors at abnormal test points in the central 5 degrees of 24-2 VFs, these eyes deserve attention to determine the severity of and functional impact on the CMVFD in early glaucoma by performing 10-2 test.