Metrological study on test methods for corneal topographer

Corneal topographer is now widely used in clinical and scientific work to assess the shape of the cornea, and it is important to know how well they perform. The studies have been carried out to test their accuracy and precision by using calibrated test surfaces internationally, while there are only few practical studies in China. In this paper, three test surfaces that resemble typical corneal shapes, including spherical, ellipsoidal and toroidal surfaces, are manufactured. The accuracy of the test surface is established by Ultrahigh Accurate 3-D Profilemeter. The experimental studies are carried out on three types of corneal topographer, and the results show that the test surfaces have good practical application. However, further study shall be gone on to find a commonly acceptable routine testing method for corneal topographer.