A great deal has changed around the world with the formation of thye International Academy of Orthokeratology(IAO) in 2011. Since that time new sections have been created in Europe(EurOk) and Asia(IAOA) have joined America(OAA) and recently Oceania(OSO) has decided to join the organization. The course covers all the new developments, leadership,meetings and goals of the IAO and its four sections with special attention to the launching of China Committee of the IAOA in August in Nanjing. (Cary M. Herzberg)

  The first measurement of corneal curvature was made in 1619 by the Jesuit Priest Christopher Scheiner. He placed several convex mirrors next to the patient’s eye and lit a candle one meter away from the patient. The equal image size reflected from the cornea and the convex mirror gave the central curvature of the cornea. Several other researchers, scientists and physiological opticists have continuously worked on measuring the central curvature of the cornea since then. Helmholtz introduced the keratometer, and Javal-Schiotz developed the ophthalmometer; both instruments have reduced the error in measurement caused by eye movement.

In 1890 Gullstrand opened the era of photokerastocopy, and was able to measure more then the central curvatures of the cornea by taking a picture of the Placido disk (1888).

Several other researchers continued the work of Gullstrand, among them a few Optometrists: Mandel, El Hage, Reynolds and Wittenberg. With the introduction of the CCD camera, it was possible to take a picture of the reflected object from the cornea and digitize the image online; hence, bypassing the need to develop the film, save time and increase accuracy. The first videokeratoscope was developed by El Hage. His device was shown  at the annual AAO meeting inLas Vegasin 1988. Two other videokeratoscopes followed, namely Eyesis and Computed Anatomy. Today many other companies are producing videokeratographs using different rings configurations.

Two main important conditions contribute to the accuracy of any given videokeratograph: the working optical distance and the ring configuration. The longer the working optical distance, the more accurate are the measurements. The shorter the working optical distance, the less accurate are the measurements. This finding was reported and confirmed by Mandel and Warring/Hannoush, in two  separate studies. As for the ring configuration, the number and distribution of the rings over the corneal surface as well as the thickness of the rings determine the representation of the cornea. The thinner the rings are combined with a high density and distribution of rings over the surface area result in a better representation of the cornea. On the other hand, a thicker ring with a smaller number of rings and smaller distribution over the surface area of the cornea result in a less accurate representation of the cornea with more.( Sami El Hage)