Effect of focal lamina cribrosa defect on glaucomatous visual field progression.

Abstract

To evaluate the association between focal, structural defects of the lamina cribrosa (LC) and glaucomatous visual field (VF) progression. Retrospective, observational study. A total of 169 patients with glaucoma (169 eyes) with a range of glaucomatous damage. Serial horizontal and vertical enhanced-depth imaging optical coherence tomography (EDI OCT) B-scans of the optic nerve head were obtained from patients with glaucoma with 5 or more prior Humphrey 24-2 VFs (Carl Zeiss Meditec, Inc, Dublin, CA). The EDI OCT scans were reviewed for the presence of focal LC defects (laminar holes or disinsertions with a diameter >100 μm). The VF progression was defined as having ≥ 2 significantly progressing test points (with a slope calculated using pointwise linear regression [PLR], worse than -1.0 dB/year at P<0.01). Age, intraocular pressure (IOP), baseline VF mean deviation (MD), disc hemorrhage, and central corneal thickness (CCT) were recorded. The relationship between focal LC defects and the rate and risk of VF progression. Mean age and VF MD at the time of EDI OCT were 69 ± 12 years and -11.49 ± 6.87 dB, respectively. Sixty eyes (36%) progressed according to PLR criteria. Progression was more common in eyes with, rather than without, focal LC defects (38/81 eyes [47%] vs. 22/88 eyes [25%], P = 0.003). Among the evaluated parameters, the presence of focal LC defects, disc hemorrhage, higher mean follow-up IOP, greater number of VFs, and longer follow-up period were significantly associated with VF progression in the multivariable analyses (odds ratios, 2.90, 4.66, 1.22, 1.25, and 1.27, respectively; P = 0.010, P = 0.002, P = 0.002, P<0.001, and P<0.001, respectively). The mean global progression rate was significantly faster in the group with focal LC defect than in the group with no focal LC defect (-0.54 ± 0.99 dB/year vs. -0.28 ± 0.52 dB/year; P = 0.031). Among the 60 progressing eyes, despite no significant difference in the mean number of progressing VF points per eye (6.7 ± 7.0 vs. 6.5 ± 4.4; P = 0.899), the mean localized progression rate was significantly faster in the eyes with focal LC defects than in the eyes with no focal LC defects (-2.85 ± 1.85 dB/year vs. -1.75 ± 0.56 dB/year; P = 0.009). Focal LC defects are strongly associated with glaucomatous VF progression, and eyes with focal LC defects tend to progress faster than those without.