Lamina Cribrosa Depth and Shape in Glaucoma Suspects. Comparison to Glaucoma Patients and Healthy Controls

Purpose: To evaluate the lamina cribrosa depth and shape parameters in glaucoma suspects compared to glaucoma patients and healthy controls. Materials and Methods: A total of 325 subjects (120 with primary open-angle glaucoma, 103 glaucoma suspects and 102 healthy controls) were included. Serial horizontal B-scan images of optic nerve head were obtained using enhanced depth imaging of the optical coherence tomography. For each of the 325 subjects, lamina cribrosa position was measured manually in 16 horizontal B-scans, hence 5200 scans in total were analyzed. In particular, lamina cribrosa depth (LCD), lamina cribrosa deflection depth (LCDD), lamina cribrosa shape index (LCSI), and its horizontal equivalent (LCSI_H) were estimated. Along lamina cribrosa parameterization, intraocular pressure, visual field, central retinal thickness, retinal nerve fiber layer thickness, and disc and neuroretinal rim areas were also measured. Results: LCD was statistically significant different (P < .001) in glaucoma patients when compared to glaucoma suspects and heathy controls (603 ± 172 μm versus 554 ± 114 μm and 531 ± 115 μm, respectively). Similarly, LCDD was statistically significant different (P < .001) in glaucoma patients when compared to glaucoma suspects and heathy controls (250 ± 78 μm versus 213 ± 54 μm and 211 ± 58 μm, respectively). No statistically significant differences were found in LCSI (P = .957). However, LCSI_H showed statistically significant differences between healthy controls and glaucoma suspects (P = .003) and between healthy controls and glaucoma patients (P = .006). Conclusions: The deformation of LC in glaucoma suspects, in terms of LCSI_H, was not statistically different from that of glaucoma patients. LCD does not have the potential to discriminate glaucoma suspects from healthy controls.