Purchase this article with an account.
S. Park, C. G. V. De Moraes, C. C. Teng, C. Tello, J. M. Liebmann, R. Ritch; Nature and Risk Factors of Initial Glaucomatous Visual Field Defect Threatening Fixation. Invest. Ophthalmol. Vis. Sci. 2010;51(13):2703.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To assess risk factors for an initial glaucomatous visual field defect threatening fixation (VFDTF) compared to an initial nasal step (NS) and its perimetric characteristics.
Based on at least two reliable, consistent 24-2 Humphrey perimetry results, 2 groups of glaucoma patients were retrospectively and consecutively enrolled: those with only VFDTF in 1 hemifield (≥3 adjacent points with P<5% within 10° of fixation, ≥2 point with P<1%, and any 1 of these lying at the innermost points) [Group A] and those with only NS in 1 hemifield (≥3 adjacent points with P<5% in the nasal periphery outside 10° of fixation, ≥2 point with P<1%, any 1 of these lying in the nasal-most point [Group B]. Demographic and ocular variables were compared between groups. VFDTF was further analyzed using 10-2 perimetry.
A total of 44 and 51 eyes (patients) were included in Group A and B, respectively. The maximum untreated intraocular pressure (IOP) was significantly lower in Group A than in B (20.3±3.4 vs 26.7±8.5 mmHg, P<0.001). Mean deviation (MD) was not significantly different between the 2 groups (-3.02±2.06 vs -2.85±1.58 dB; Group A vs B, P=0.643), but pattern standard deviation (PSD) was significantly greater in Group A than in B (5.24±2.23 vs 3.73±1.51 dB, P=0.001). Mean age (63 vs 65 years), proportion of women (66 vs 71%), disc area by HRT (2.00 vs 1.87 mm2), spherical equivalent (-1.3 vs -1.8 D), central corneal thickness (535 vs 537 µm), and foveal threshold (34.5 vs 34.4 dB) showed no significant differences between the 2 groups (Group A vs B, all P>0.1). In Group A, 24-2 PSD had a stronger significant correlation with 10-2 MD (R: 0.65 vs 0.46) or 10-2 PSD (R: 0.70 vs 0.37), compared to 24-2 MD (P<0.001). At least 1 point with P<1% was present within 2° of fixation on 10-2 perimetry in 27/44 (61.4%) patients of Group A. MD, PSD, and worst sensitivity among and mean sensitivity of the innermost points on 24-2 in Group A had no significant correlation with the mean sensitivity within 2° of fixation on 10-2 (all P>0.06).
Initial VFDTF tended to occur in glaucoma patients with low IOP, and had deeper local defects, with 24-2 PSD being a better parameter representing the sensitivity within 10° of fixation than 24-2 MD. Patients with initial VFDTF on 24-2 perimetry quite often had a field defect within 2° of fixation, but 24-2 parameters had poor correlation with the sensitivity within 2° of fixation, requiring 10-2 perimetry.
This PDF is available to Subscribers Only