Asian shares edged down on Thursday and the dollar was treading water, with investors on ice ahead of a meeting of European Union leaders later in the session as Greece continued last-minute efforts to avert a default. Athens’ talks with creditors bogged down on details, with next week’s deadline to repay 1.6 billion euros ($1.79 billion)to the International Monetary Fund looming, and threatening to trigger Greece’s removal from the euro zone. MSCI’s broadest index of Asia-Pacific shares outside Japan was down about 0.3 percent.