What Eye Tests do you need?
There are many instruments that your keratoconus expert will use to diagnose and track your disease, depending on their practice and how often they see this disease.
Corneal Topography (corneal shape)
A corneal topographer (such as a Medmont or Orbscan) measures and maps the exact shape of your eye. It produces a scan like the one here. This is the single most important tool your optometrist will have in diagnosing keratoconus.
It also accurately monitors your eyes to see if they are getting worse over time. This is called progression of the disease.
The topographer also helps with choosing the best possible contact lens for your eye.
A scan of your cornea will instantly show the characteristic hallmark appearance of keratoconus (see image).
Global Pachymetry (Corneal thickness)
Keratoconus is firstly a progressive corneal thinning. Being able to measure how thick the cornea is becomes critical in monitoring progression.
The eye condition can be picked up even earlier through repeated corneal thickness measurements, which show subtle corneal thinning before any shape-change occurs.
This test is called global pachymetry using an instrument called an Optical Coherence Tomographer.
A Pentacam can also be used to provide similar information about your eyes.