ASR Hip Resurfacing, Chrome and Cobalt Levels and Effect on Vision

The ASR Hip Resurfacing System is a type of hip implant that was made from metal components containing chromium and cobalt. These metals can gradually wear down and release particles into the bloodstream. This study is measuring chromium and cobalt blood levels in people who have an ASR hip replacement still in place, and checking whether elevated metal levels are associated with any changes in their vision. This helps researchers and doctors better understand the potential health effects of metal-on-metal hip implants. You may be eligible if: - You have an ASR hip replacement implant You may NOT be eligible if: - You have known pre-existing visual problems Talk to your doctor about whether this trial might be right for you.