There are several tests your doctor may perform to determine the presence and severity of a corneal disease.
Slit Lamp Exam
To begin, your eye doctor will review your medical and family history, and examine your eyes and eyelids using a slit lamp microscope. Often, this is sufficient to confirm injury, such as a scratch on the cornea, or signs of infection.
Much like a topographic map of the earth, a corneal topography displays the elevation of different parts of the cornea.
Evaluate Corneal Shape and Thickness
In some cases, especially when corneal dystrophy is suspected, the doctor may use topography or keratometry (non-invasive imaging tests) to evaluate the shape and curvature of the cornea. Pachymetry is a type of test which measures the thickness of the cornea.
Assess Cells and Tear Film
Cultures and biopsies can also shed light on your corneal health. For example, a more detailed assessment might look at the health of the endothelial cells, the outermost portion of the cornea. Healthy tears also play a key role in protecting the cornea.