Dr Moïse Tourabaly · Key points
This cross-section shows two layers of the cornea: on the surface, the very thin epithelium; beneath it, the stroma, which makes up most of its thickness.
The cornea in cross-section
Epithelial thickness (OCT)
Normally, the epithelium has a fairly even thickness across the whole cornea: the map is uniform.
When the stroma bulges, the epithelium compensates: it thins at the apex of the cone and thickens around it. The surface then looks almost regular, but the epithelial map becomes asymmetric and can reveal an early form before standard topography does.
Diagnosis always combines several tests: topography, corneal tomography, thickness (pachymetry) and follow-up over time.
Educational diagram · Dr Moïse Tourabaly, ophthalmologist. It does not replace a consultation.