AMA, the German buying group, has obtained a license from Karl Lagerfeld, the well-known German fashion designer, for distribution in its 1,500 affiliated optical stores, starting last Jan. 1. The Karl Lagerfeld line will be added to another exclusive brand of AMA, St. Moritz. AMA has also signed a deal with a German refractive surgery association, VSDAR, allowing AMA's opticians and optometrists to get special training to better handle LASIK patients before and after surgery.