Lamina Cribrosa in Glaucoma: Diagnosis and Monitoring

The lamina cribrosa is the putative site of retinal ganglion cell axonal injury in glaucoma. Although histological studies have provided evidence of structural changes to the lamina cribrosa, even in early stages of glaucoma, until recently, the ability to evaluate the lamina cribrosa in vivo has been limited. Recent advances in optical coherence tomography, including enhanced depth and swept-source imaging, have changed this, providing a means to image the lamina cribrosa. Imaging has identified general and localized configurational changes in the lamina of glaucomatous eyes, including posterior laminar displacement, altered laminar thickness, and focal laminar defects with spatial association with conventional structural and functional losses. In addition, although the temporal relationship between changes to the lamina cribrosa and glaucomatous retinal ganglion cell loss is yet to be elucidated, quantitative measurements of laminar microarchitecture have good reproducibility and offer the potential to serve as biomarkers for glaucoma diagnosis and progression.