If you don't hear from a doctor today, I would recommend going to 20 mg. The headache and vision problems are very concerning. I came close to losing some vision from GCA, but I started treatment just in time to save it. I took Prednisone for 13 months, and I'm in my third year of Actemra. Once I started treatment, I didn't have any more symptoms or flares. But Actemra isn't completely effective for everyone. The chances are you won't lose vision, since you're taking Prednisone and Actemra, but you should see your rheumatologist as soon as possible