Bayer suffered a setback in its home market of Germany on Thursday when a healthcare cost watchdog said it was unable to assess whether its new eye medication Eylea offered an advantage over a rival product from Novartis. The opinion issued by the German Institute for Quality and Efficiency in Health Care, or IQWiG, could affect the level of reimbursement by public insurers for Eylea in Germany. IQWiG compared trial data on Eylea and Novartis's Lucentis for treatment of macular edema - a build-up of fluid under the centre of the retina following a blockage of the retina's major vein.