I am on Gilenya and at risk for macular edema. During my semi-annual visit with my ophthalmologist, I mentioned that my eyes were dry and I sometimes used lubricating eye drops as often as every 30 minutes. I had them with me and when he saw that they were a generic brand, he said that I shouldn't use them for than 4 times per day, due to the preservatives they contained. He recommended Systane and said that this brand could be used as often as needed. I forgot to ask if Systane is available as an Rx, as I've met my out-of-pocket for the year. erash Do you know?