The artistic director of Russia’s Bolshoi ballet company, who was victim of a horrific acid attack in January, has for the first time left his clinic in Germany to watch the troupe on tour in London, Russian state television said Tuesday. Sergei Filin, who suffered severe facial burns and an almost complete loss of eyesight in the January attack, left his clinic in the German city of Aachen to watch a performance by the Bolshoi on its tour at the Royal Opera House in Covent Garden.