[Enhanced Depth Imaging- optical coherence tomography technique and the lamina cribrosa in glaucoma].

The importance of the lamina cribosa in the pathogeny of glaucoma is well known, although exploration utilizing the “Enhanced Depth-Imaging” (EDI) technique with spectral domain optic coherence tomography (DS-OCT) is quite recent. Initially, it was used to assess and quantify choroidal thickness1–3 and now it has facilitated a quantum leap in qualitative, quantitative and dynamic in vivo examination of the lamina cribosa. The lamina cribosa is a hyper-reflective structure with well defined limits and traversed by multiple hypo-reflecting columns which, in the interface section, match low reflectiveness orifices (Fig. 1). In addition to the descriptive aspects, we are able to quantify lamina cribosa thickness as well as that of the overlying prelaminary tissue and the cup depth (Fig. 1) together with the anterior and posterior limits. The latter measure is the least reproducible of all. The thickness of the lamina cribosa is significantly greater in normal subjects than in ocular hypertensives, and thicker in these then in glaucoma patients. The degree of thinning significantly correlates with the severity of glaucoma and increases together with glaucomatous damage.4 On the other hand,