The mantra of modern keratoconus management is: diagnose early, stop progression, rehabilitate vision.
There are a number of diagnostic instruments that are used to diagnose and monitor keratoconus. The corneal topographer is one such instrument and essentially it maps out the contours of the anterior corneal structure. I, as well as many others, was taught in school that corneal topography, aka videokeratography, is the gold standard for diagnosing keratoconus. There are a number of different corneal topography systems, each of which provides slightly different information about the cornea surface shape, but all the principles are the same. These instruments have come to exist due in part to the principals of the keratometer and the placido disk.
Placido Disk Keratoscope
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