[Indirect contact specular microscopy. A new technique for the in vivo examination of the posterior corneal surface (author's transl)].

A new application of contact specular microscopy (CSM) is presented. This technique allows, in addition to conventional CSM and by augmentation of the applanation pressure of the CSM dipping cone, to observe changes on the posterior corneal surface in a three-dimensional mode. This technique gives valuable information in cases of preendothelial, endothelial, and retroendothelial modifications, leading to prominent changes of the posterior corneal surface. Thus, it is a very suitable method to interpret in vivo morphological findings. A hypothesis of the mechanisms leading to the three-dimensional image is presented. Based on these optical considerations the term 'indirect CSM' is proposed in contrast to the conventional direct CSM.