1. From the Department of Ophthalmology,2The Ludwig Boltzmann Institute of Retinology and Biomicroscopic Laser Surgery, and the
2. Institute for Medical Statistics, RWTH, Aachen, Germany.
3. The Ludwig Boltzmann Institute of Retinology and Biomicroscopic Laser Surgery, and the
4. Department of Pathology and Bacteriology, Rudolf Foundation Clinic, Vienna, Austria; and the