The Keratoconus Examination

Keratoconus is a biomechanical problem of the cornea which leads to optical problems.  It is a progressive condition which, aside from distorting the cornea's natural optics, can also lead to scarring and other problems.  The presentation and impact of keratoconus can vary widely from person to person. 

In order to fully assess your keratoconus, understand the likely future course of the disease, and make appropriate treatment recommendations, an extensive eye examination is performed along with several specialized tests to fully analyze your problem. These tests also give you a complete baseline for your ongoing care in the future. 

The CLEI Center for Keratoconus incorporates all of the latest diagnostic technologies to assess your KC and determine the proper course of treatment.  Some of  these diagnostic tools include:

Corneal topography instruments to assess your cornea's optical surface.  These are corneal maps that can assess many indices of your individual corneal shape and structure.  We use a number of instruments, each of which may give different clues to the corneal shape, including the Pentacam, Orbscan, EyeSys, and Keratron units). 

Wavefront analysis of the eyes optical system and assessment of aberration profile.  Because of the optical irregularities of the keratoconic cornea, light is not completely focused.  This causes scattering of light rays and the formation of "visual static", much like the static that you may find on a TV.  Wavefront analysis defines the particular types of static that are present in the keratoconic cornea.

Optical Response Analyser: This is a new instrument which has recently been introduced. It measures the elasticity and flexibility of the cornea and is the first true clinical measurement of corneal biomechanics in KC. This may allow for better diagnosis of early keratoconus, help to predict its possible progression, and allow for monitoring of changes in the keratoconic cornea.

Pupil size by infrared pupillometry

Contrast sensitivity determines the influence of "visual static" from keratoconus on your optical function.

Binocularity testing

Corneal thickness (ultrasonic pachymentry) measurements detect the degree of keratoconic thinning.  In KC, the cornea is thinner and weaker than normal.  Changes over time can be monitored by periodic assessment of the corneal thickness measure both by ultrasound and by imaging on the Pentacam unit.

Refraction (determination of prescription).  This is more difficult in the keratoconic patient, since the corneal optics are distorted.  Various techniques allow us to best measure your refraction and optimize, as best possible, your glasses corrected vision with keratoconus. 

The goal of this comprehensive keratoconus evaluation is multifold. First, we want to fully assess and define your keratoconus in order to monitor progression over time. Second, this testing will allow us to best recommend a course of treatment (whether optical or surgical) to optimize your visual function.