Factors associated with focal lamina cribrosa defects in glaucoma

Abstract

Purpose: To assess factors associated with focal lamina cribrosa (LC) defects in glaucoma.

Methods: Serial enhanced depth imaging (EDI) optical coherence tomography (OCT) B-scans of the optic nerve head were obtained from glaucoma patients. EDI OCT scans were reviewed for focal LC defects (laminar holes or disinsertions). Evaluated clinical factors included age, central corneal thickness, visual field (VF) mean deviation (MD), exfoliation syndrome, normal-tension glaucoma (NTG), disc hemorrhage, and intraocular pressure (IOP) during past follow-up.

Results: One hundred forty-eight glaucomatous eyes (148 patients; mean age, 68 ± 12 years; mean VF MD, -11.63 ± 6.96 dB) were included. Sixty-seven (45%) eyes had focal LC defects and 81 (55%) did not. Eyes with focal LC defects had a higher prevalence of both disc hemorrhage (25% vs. 6%) and NTG (33% vs. 9%) and worse VF MD (-14.12 vs. -9.58 dB) than those without focal LC defects (P = 0.002, P < 0.001, and P < 0.001, respectively). In the multivariate logistic regression analysis, higher frequency of disc hemorrhage detection (odds ratio [OR], 3.63; P = 0.032), a diagnosis of NTG (OR, 4.23; P = 0.005), and worse VF MD (OR, 1.11; P < 0.001) were significant factors associated with the presence of focal LC defects. Disc hemorrhage developed in the same half of the disc as the largest or the second largest focal LC defect in 15 of 17 eyes (88.2%).

Conclusions: Disc hemorrhage, a diagnosis of NTG, and more advanced glaucoma status are associated with focal LC defects. Future studies are needed to elucidate the cause-and-effect relationships between focal LC defects and these factors.

Keywords: glaucoma; lamina cribrosa; optical coherence tomography.