Parafoveal Scotoma Progression in Glaucoma: Humphrey 10-2 versus 24-2 Visual Field Analysis

Abstract

To compare the performance of 10-2 versus 24-2 visual fields (VFs) in detecting progression of initial parafoveal scotoma (IPFS) in glaucomatous eyes. Retrospective, observational study. Glaucoma patients with the following criteria: (1) an IPFS (≥ 3 adjacent points with P<0.05 within the central 10° degrees of fixation, 1 point or more with P<0.01 lying at the innermost paracentral points, and no scotoma outside the central 10°) in either hemifield based on 2 reliable Humphrey 24-2 Swedish interactive threshold algorithm standard VFs, and (2) 5 or more 10-2 and 24-2 VFs. Based on threshold map sensitivities, VF progression, defined as having 1 or more significantly progressing point(s) with a slope of sensitivity of less than -1.0 dB/year at P<0.01, was evaluated using pointwise linear regression. The number of progressing eyes in 10-2 and 24-2 VF analyses. Fifty eyes (50 patients) were included (mean age ± standard deviation, 62 ± 9 years). Mean follow-up period (5.7 vs. 5.6 years) and number of VFs (7.6 vs. 7.8) were similar between 10-2 and 24-2 analyses (all P>0.3). Significantly more progressing eyes were detected in 10-2 than in 24-2 analyses (24 vs. 11 eyes; P = 0.007). This difference became greater within the central 10° (24 vs. 4 eyes; P<0.001). Four of the 11 progressing eyes in 24-2 analysis were missed in 10-2 analysis, whereas 17 of the 24 progressing eyes in 10-2 analysis were missed in 24-2 analysis. The 4 progressing eyes missed in 10-2 analysis had progressing point(s) only outside the central 10° in 24-2 analysis. The other 3 eyes with progressing point(s) only outside the central 10° in 24-2 analysis were detected as progressing in 10-2 analysis. Similar results were obtained when more stringent criteria (at least 2 significantly progressing points within the same hemifield) were used for VF progression. The 10-2 VF detects more progressing eyes than the 24-2 VF in glaucoma patients with IPFS, suggesting that closer surveillance of the central VF using testing algorithms with closely spaced grids is warranted in eyes with parafoveal scotomas. Proprietary or commercial disclosure may be found after the references.