角膜後面曲率半径の測定

Measurement of the Posterior Curvature Radius of the Cornea by Photographic Method

緒言

　角膜後面曲率半径の測定は，角膜乱視，残余乱視の研究あるいは，Phacometryの精度を向上させるためなどには大切であるが，従来その報告は少ない。そこで今回は，Purkinje-Sanson像の第1像（角膜前面反射像）および第2像（角膜後面反射像）を利用した測定方法，測定条件およびその精度につき検討し，十分使用できる方法であることが判明したので，ここに報告する。

The apparatus for ophthalmophacometry, by which the first and second Purkinje-Sanson images were photographed, was used for mea-suring the posterior curvature radius of the cornea.

In order to determine the best optical arran-gement of the light source and the accuracy of this measurement, experimental and theoretical studies were performed using four artificial model corneas. It was found that the best op-tical position of the light source was at the angle of 20° from the optical axis of the camera lens.