Canadian biotechnology company QLT Inc. said Monday it will have all U.S. rights to the eye drug Visudyne after reworking a marketing agreement with Novartis AG. Starting Jan. 1, QLT will have exclusive U.S. rights to Visudyne, a treatment for "wet" age-related macular degeneration, which is a common cause of blindness. Novartis, a Swiss drugmaker, will have the right to make and sell the drug in all other countries. It will pay QLT a 20 percent royalty on all sales until Dec. 31, 2014. After that, QLT will get a 16 percent royalty until the end of 2019. Visudyne is one of QLT's two main products. The other is Eligard, a treatment for the symptoms of prostate cancer. QLT sold the rights to Eligard earlier this month, when it sold its entire U.S. business, although it will still receive royalties on Eligard sales. Since early 2008, QLT has been streamlining its business to focus on Visudyne. Sales of the drug sales have been hurt by the approval of rival products like Roche's Lucentis. Due to a restructuring in 2008, Novartis no longer has a specific sales force for eye drugs. QLT said Visudyne sales fell 34 percent in 2008.