Can you have a corneal topography scan with an opaque cornea?

Answer:
A corneal topography scan measures the shape of the front surface of the cornea (the clear dome-shaped window at the front of the eye). A corneal tomography measures both the front and back surfaces of the cornea. This gives a more comprehensive representation of the total shape and power of the cornea.

Modern corneal topography machines are actually tomography machines since understanding the overall curvature variations of the cornea is much more useful in diagnosing and monitoring disease. Since tomography machines rely on light, having an opaque cornea produces either very limited or no results about the corneal shape.