10-2 Versus 24-2 Visual Field Progression Analysis in Glaucomatous Eyes with Initial Parafoveal Scotomata

Abstract

Purpose: : To compare the efficacy of 10-2 vs. 24-2 visual fields (VFs) in detecting progression of initial parafoveal scotoma (IPFS) in glaucomatous eyes.

Methods: : Glaucoma patients with the following criteria were included: 1) an IPFS in either hemifield based on 2 reliable 24-2 SITA-Standard VFs (≥3 adjacent points with P<5% within the central 10 degrees of fixation, ≥1 point with P<1% lying at the innermost paracentral points, and no scotoma outside the central 10 degrees) and 2) five or more 10-2 and 24-2 VFs (initial 10-2 and 24-2 VFs obtained <6 months apart). Based on 10-2 and 24-2 full threshold map values, progression rates were calculated using pointwise linear regression (PLR) analysis and averaged to generate the global progression rate (dB/yr) of each eye. VF progression was defined as having ≥1 significantly progressing point(s) (slope <-1.0 dB/yr at P<0.01). The rates at these points were averaged to generate the localized progression rate (dB/yr) of each eye. The number of progressing eyes, localized progression rate, and number of progressing points were compared between 10-2 and 24-2 VFs within the central 10 degrees only.

Results: : Fifty eyes (50 patients) were included (mean age, 61.9±8.7 yr; 10-2 VF mean deviation [MD], -6.2 ± 3.4 dB; 24-2 VF MD, -3.4 ± 3.3 dB). Mean follow-up period (5.7 ± 2.1 vs. 5.6 ± 1.9 yr) and number of VFs (7.6 ± 2.4 vs. 7.8 ± 2.9) were similar for 10-2 and 24-2 tests (10-2 vs. 24-2, all P>0.3). Mean global progression rate was significantly greater in 10-2 analysis (-0.40±0.51 dB/yr) than in 24-2 analysis (-0.23 ± 0.28 dB/yr) (P=0.01). Within the central 10 degrees of VF, 10-2 analysis detected significantly more progressing eyes than 24-2 analysis (24 vs. 7 eyes; P<0.001). Within the central 10 degrees, mean localized progression rate (-1.3 vs. -0.4 dB/yr) and mean number of progressing points (2.5 vs. 0.5) were significantly greater in 10-2 than in 24-2 analyses (10-2 vs. 24-2; all P<0.001).

Conclusions: : In glaucoma patients with an IPFS, the 10-2 VF detects more progressing eyes than the 24-2 VF, suggesting that closer surveillance of the central VF using 10-2 VF is warranted in these eyes.

Keywords: perimetry • visual fields • detection