M. Vogel – författare

References ............................................... 59 Subject Index ............................................. 65 6 Introduction The retina as an organ of perception of light, colour, shape and movement has been the subject of numerous and intensive light- and electron-microscopical investigations. To date the interest in these has largely been concentrated on the structure of the ma­ ture retina and the genesis of its cellular elements. The first exhaustive observations on the development of the retina in vertebrates were made by Babuchin (1863). Using the retinae of chicken embryos, he showed that Millier's radial fibres and the ganglion cells are the first to develop, while the receptor segments are the last. Subsequently, the early differentiation of Millier's radial fibres was often reaffirmed (Cajal, 1893; Meller, 1968; Bhattacharjee and Sanyal, 1975; and others). Furthermore, Babuchin had already indicated that the structural development in the area of the posterior pole is very rapid compared with those regions of the retina which are situated more peripherally. Today, when comparing results of electron-mi­ croscopical investigations, this fact is of particular importance, since in each case only very limited areas of the retina can be examined. Schultze (1867a, b) pointed out the uniformity of origin and the general classifica­ tion of light-perceiving elements into inner and outer segments, thus contesting the hitherto generally held opinion that these structures, like the pigment epithelium, ori­ of the eye cup. In 1881 Ogneff discovered the analogous ginate from the outer leaf mode of formation in birds and mammals.

The international symposium on transposition of the great arteries was held in Munich on May 3-5, 1991. It was organized by the German Heart Center Muni eh with two aims: firstly, to commemorate the 25th anniversary of Dr. Rashkind's publication: "Creation of an atrial septal defect without thoracotomy" (which appeared in 1966 in the Journal of the American Medical Association), and to honor this great pediatric cardiologist, who was one the pioneers of interventional catheterization. secondly, to give an overview of current medical knowledge about the pre- and postnatal diagnosis, medical and surgical treatment, and postoperative evalua- tion of transposition of the great arteries. Fig. 1. Dr. Rashkind in his Iabaratory checking his balloon catheter V This symposium brought tagether embryologists, morphologists, experts in fetal cardiology, pediatric cardiologists, and pediatric cardiac surgeons from 10 different countries. Thus, we were able to describe the current state-of-the-art of pre- and postnatal management and the surgical treatment of this second most common con- genital cyanotic anomaly of the heart. Dr.Rashkind's approach to create an atrial septal defect in the setting of com- plete transposition of the great arteries dramatically changed the natural history of this cyanotic heart defect, which carried a 90% neonatal mortality before this effec- tive palliation became available.