Evaluation of the lamina cribrosa morphology in correlation to retinal nerve fiber layer thickness

Abstract

Aim The aim of this study was to assess the correlation between lamina cribrosa (LC) morphology and glaucoma severity using spectral domain optical coherence tomography. Patients and methods This is a comparative cross-sectional study that included 40 eyes divided into 20 eyes having primary open-angle glaucoma and 20 normal control eyes. Serial horizontal B-scan images of the optic nerve head were obtained using enhanced depth imaging optical coherence tomography. Images were analyzed using the Cirrus HD software. Statistical analysis was conducted to compare the lamina cribrosa depth (LD) and lamina cribrosa thickness (LT) with retinal nerve fiber layer (RNFL) thickness and visual field mean deviation. Results The mean±SD values of the LD, LT, and visual field mean deviation were 533.5±66.8, 188.4±15.8 µm, and −4.3±3.4 dB, respectively. On linear regression analysis, LD, LT, and intraocular pressure were significantly correlated with RNFL thickness (P<0.001, 0.001, and 0.01, respectively). The mean LD was significantly greater in the glaucoma group compared with the normal control group (P<0.001). In eyes with glaucoma, the LC was thinner and located more posteriorly compared with the normal control eyes. Conclusion There was a generalized decrease in LT and posterior displacement of the LC in the glaucomatous patients compared with healthy controls. Thus, the LC morphology can help differentiate glaucomatous from normal eyes.

Keywords

• glaucoma
• lamina cribrosa
• lamina cribrosa depth
• lamina cribrosa thickness
• optical coherence tomography